European Journal of Pharmacology (v.527, #1-3)
Editorial Board (ii).
Pharmacogenomics and cardiovascular drugs: Need for integrated biological system with phenotypes and proteomic markers by Gérard Siest; Jean-Brice Marteau; Sandy Maumus; Hind Berrahmoune; Elise Jeannesson; Anastasia Samara; Anne-Marie Batt; Sophie Visvikis-Siest (1-22).
After summarizing the most well-known genes involved in drug metabolism, we will take as example of drugs, the statins, considered as very important drugs from a Public-Health standpoint, but also for economical reasons. These drugs respond differently in human depending on multiple polymorphisms. We will give examples with common ApoE polymorphisms influencing the hypolipemic effects of statins. These drugs also have pleiotropic effects and decrease inflammatory markers. This illustrates the need to separate clinical diseases phenotypes in specific metabolic pathways, which could propose other classifications, of diseases and related genes.Hypertension is also a good example of clinical phenotype which should be followed after various therapeutic approaches by genes polymorphisms and proteins markers.Gene products are under clear environmental expression variations such as age, body mass index and obesity, alcohol, tobacco and dietary interventions which are the first therapeutical actions taken in cardiovascular diseases. But at each of the five steps, within a pharmacoproteomic strategy, we also need to use available information from peptides, proteins and metabolites, which usually are the gene products. A profiling approach, i.e., dealing with genomics, but now also with proteomics, is to be used.
Keywords: ABC transporter; Antiobesity drug; Cardiovascular disease; Cardiovascular drug; Drug-metabolizing enzyme; Drug target; Inflammation; Nutrigenetics; Nutrigenomics; Obesity; Pharmacodynamic; Pharmacogenetic; Statin;
Inhibition of 1-methyl-4-phenylpyridinium-induced mitochondrial dysfunction and cell death in PC12 cells by sulfonylurea glibenclamide by Chung Soo Lee; Yun Jeong Kim; Hyun Hee Ko; Eun Sook Han (23-30).
The present study investigates the effect of sulfonylurea glibenclamide on the cytotoxicity of 1-methyl-4-phenylpyridinium (MPP+) in differentiated PC12 cells in relation to changes in the mitochondrial membrane permeability. Glibenclamide and tolbutamide reduced the MPP+-induced cell death and GSH depletion concentration dependently with a maximal inhibitory effect at 5–10 μM. Despite the toxic effect at 20 μM, sulfonylureas showed an inhibitory effect. N-Acetylcysteine, superoxide dismutase, catalase, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and Mn(III) tetrakis(4-benzoic acid)porphyrin chloride inhibited the cytotoxicity of MPP+. Glibenclamide attenuated the nuclear damage, changes in the mitochondrial membrane permeability, caspase-3 activation and formation of reactive oxygen species due to MPP+ in PC12 cells. The results show that glibenclamide may reduce the MPP+-induced viability loss in PC12 cells by suppressing the changes in the mitochondrial membrane permeability, leading to the release of cytochrome c and subsequent activation of caspase-3, which are associated with the increased reactive oxygen species formation and depletion of GSH.
Keywords: 1-Methyl-4-phenylpyridinium; Glibenclamide; PC12 cell; Mitochondrial membrane permeability; Cell injury;
Inhibitory effects of a benz[f]indole-4,9-dione analog on cancer cell metastasis mediated by the down-regulation of matrix metalloproteinase expression in human HT1080 fibrosarcoma cells by Hyen Joo Park; Hyun-Jung Lee; Hye-Young Min; Hwa-Jin Chung; Myung Eun Suh; Hye-Young Park-Choo; Choonmi Kim; Hwa Jung Kim; Eun-Kyung Seo; Sang Kook Lee (31-36).
In our previous study, a synthetic benz[f]indole-4,9-dione analog, 2-amino-3-ethoxycarbonyl-N-methylbenz[f]indole-4,9-dione (SME-6), exhibited a potential anti-tumor activity. We, in this study, further explored the anti-metastatic and anti-invasive effect of SME-6 by determining the regulation of matrix metalloproteinases (MMPs). MMPs, zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix as well as non-matrix substrates. On this line, we examined the influence of SME-6 on the expressions of MMP-2, -9, membrane type 1-MMP (MT1-MMP), tissue inhibitor of metalloproteinases (TIMP-1, -2), and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent suppressions of MMPs and TIMP-2 mRNA levels were observed in SME-6-treated HT1080 human fibrosarcoma cells detected by reverse transcriptase–polymerase chain reaction. TIMP-1 mRNA level, however, was induced in a dose-dependent manner. Gelatin zymographic analysis also exhibited a significant down-regulation of MMP-2 and -9 expression in HT1080 cells treated with SME-6 compared to controls. Furthermore, SME-6 inhibited the invasion, motility, and migration of tumor cells. Taken together, these data provide a possible role of SME-6 as a potential antitumor agent with the markedly inhibition of the metastatic and invasive capacity of malignant cells.
Keywords: Benz[f]indole-4,9-dione; 2-Amino-3-ethoxycarbonyl-N-methylbenz[indole-4,9-dione; Extracellular matrix; Matrix metalloproteinase; Tissue inhibitor of metalloproteinase; Membrane type 1-matrix metalloproteinase;
2-(2-Br-phenyl)-8-methoxy-benzoxazinone (HPW-RX2), a direct thrombin inhibitor with a suppressive effect on thromboxane formation in platelets by Chin-Chung Wu; Tsai-Wei Wang; Wei-Ya Wang; Pei-Wen Hsieh; Yang-Chang Wu (37-43).
2-(2-Br-phenyl)-8-methoxy-benzoxazinone (HPW-RX2), a newly synthetic benzoxazinone derivative, has previously been shown to inhibit rabbit platelet aggregation caused by thrombin and arachidonic acid. In the present study, the mechanism for the antiplatelet effect of HPW-RX2 was further investigated. In human platelets, HPW-RX2 concentration-dependently inhibited platelet aggregation, ATP release, P-selectin expression, and intracellular calcium mobilization caused by thrombin. In contrast, HPW-RX2 had no significant effect on either SFLLRN- or GYPGKF-induced platelet aggregation, indicating that HPW-RX2 did not interfere with platelet thrombin receptors. Moreover, HPW-RX2 inhibited the amidolytic activity of thrombin and prolonged the fibrinogen clotting time. These results suggest that the inhibitory effect of HPW-RX2 on thrombin-induced platelet aggregation is via direct inhibition of thrombin proteolytic activity. Besides the inhibition on thrombin, HPW-RX2 also prevented platelet aggregation, ATP release, and increase in [Ca2+]i caused by arachidonic acid and low concentration collagen. In a parallel manner, both arachidonic acid-induced thromboxane B2 and prostaglandin D2 formations were decreased in platelets treated with HPW-RX2. This indicates that HPW-RX2 is able to inhibit the arachidonic acid cascade at the cyclooxygenase level. This is the first report of a benzoxazinone derivative possessing both thrombin and cyclooxygenase inhibitory properties. The dual effect of HPW-RX2 might provide extra therapeutic benefits for treatment of arterial thrombosis.
Keywords: Antiplatelet agent; Thrombin; Thromboxane A2;
Inhibition of acute nociceptive responses in rat spinal cord by a bradykinin B1 receptor antagonist by Rachel K. Conley; Alan Wheeldon; Janine K. Webb; Robert M. DiPardo; Carl F. Homnick; Mark G. Bock; Tsing-Bau Chen; Raymond S.L. Chang; Douglas J. Pettibone; Susan Boyce (44-51).
This study used behavioural and in vivo electrophysiological paradigms to examine the effects of systemic and spinal administration of a bradykinin B1 receptor antagonist, compound X, on acute nociceptive responses in the rat. In behavioural experiments, compound X significantly increased the latency to withdraw the hindpaw from a radiant heat source after both intravenous and intrathecal administration, without affecting motor performance on the rotarod. In electrophysiological experiments, both intravenous and direct spinal administration of compound X attenuated the responses of single dorsal horn neurones to noxious thermal stimulation of the hindpaw. These data show that the antinociceptive effects of a bradykinin B1 receptor antagonist are mediated, at least in part, at the level of the spinal cord and suggest a role for spinal bradykinin B1 receptors in acute nociception.
Keywords: Bradykinin B1 receptor; Antinociception; Spinal cord; (Rat);
Modulation of striatal dopamine release in vitro by agonists of the glycineB site of NMDA receptors; interaction with antipsychotics by Stephen Bennett; Benjamin Gronier (52-59).
The N-methyl-d-aspartate (NMDA) glutamate receptor possesses an obligatory co-agonist site for d-serine and glycine, named the glycineB site. Several clinical trials indicate that glycineB agonists can improve negative and cognitive symptoms of schizophrenia when co-administered with antipsychotics. In the present study we have investigated the effects of glycineB agonists on the endogenous release of dopamine from preparations of rat striatal tissue prisms in static conditions. The glycineB agonists glycine (1 mM) and d-serine (10 μM), but not d-cycloserine (10 μM), substantially increased the spontaneous release of dopamine, but significantly reduced the release of dopamine evoked by NMDA. The effect of glycine on spontaneous release was abolished by the non-competitive NMDA antagonists 5R,10S-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5,10-imine (MK-801, 10 μM) and ifenprodil (5 μM), but was only partially suppressed by the competitive antagonist 4-(3-phosphonopropyl)-piperazine-2-carboxylic acid (CPP, 10 μM). The selective inhibitor of the glial glycine transporter GlyT1 N[3-(4′-fluorophenyl)-3-(4′-phenylphenoxy)propyl]sarcosine (NFPS, 10 μM) significantly increased the release of dopamine in an MK-801-sensitive manner. Interestingly, haloperidol (1 μM), but not clozapine (10 μM), prevented the effects of glycine. This study shows that glycineB modulators can control dopamine release by interacting with a distinctive NMDA receptor subtype with which some typical antipsychotics can interfere.
Keywords: GlycineB site; N-methyl-d-aspartate receptors; Dopamine; Schizophrenia; Antipsychotic;
Effect of diabetes on the mechanisms of intrathecal antinociception of sildenafil in rats by Claudia Ivonne Araiza-Saldaña; Gerardo Reyes-García; Deysi Yadira Bermúdez-Ocaña; Francisca Pérez-Severiano; Vinicio Granados-Soto (60-70).
The mechanism of intrathecal antinociceptive action of the phosphodiesterase 5 inhibitor sildenafil was assessed in diabetic rats using the formalin test. Intrathecal administration of sildenafil (12.5–50 μg) produced a dose-related antinociception during both phases of the formalin test in non-diabetic and diabetic rats. Intrathecal pretreatment with N-l-nitro-arginine methyl ester (l-NAME, nitric oxide (NO) synthase inhibitor, 1–50 μg), 1H-(1,2,4)-oxadiazolo(4,2-a)quinoxalin-1-one (ODQ, guanylyl cyclase inhibitor, 1–10 μg), KT5823 (protein kinase G (PKG) inhibitor, 5–500 ng), charybdotoxin (large-conductance Ca2+-activated K+ channel blocker, 0.01–1 ng), apamin (small-conductance Ca2+-activated K+ channel blocker, 0.1–3 ng) and glibenclamide (ATP-sensitive K+ channel blocker, 12.5–50 μg), but not N-d-nitro-arginine methyl ester (d-NAME, 50 μg) or saline, significantly diminished sildenafil (50 μg)-induced antinociception in non-diabetic rats. Intrathecal administration of ODQ, KT5823, apamin and glibenclamide, but not l-NAME nor charybdotoxin, reversed intrathecal antinociception induced by sildenafil in diabetic rats. Results suggest that sildenafil produces its intrathecal antinociceptive effect via activation of NO–cyclic GMP–PKG–K+ channels pathway in non-diabetic rats. Data suggest that diabetes leads to a dysfunction in NO and large-conductance Ca2+-activated K+ channels. Sildenafil could have a role in the pharmacotherapy of diabetes-associated pain.
Keywords: Sildenafil; Cyclic GMP; Protein kinase G; K+ channel; Spinal processing;
Development of antinociceptive tolerance and physical dependence following morphine i.c.v. infusion in mice by Natalie R. Lenard; Sandra C. Roerig (71-76).
The chronic i.c.v. infusion of morphine has been reported for rats but not for mice. In the current report, the antinociceptive tolerance to both i.c.v. morphine infusion and s.c. implantation of morphine pellets in mice was compared. Physical dependence after i.c.v. morphine infusion was also evaluated. Osmotic minipumps were filled with morphine (50 mM), connected to i.c.v. cannulae, and implanted s.c. to deliver 50 nmol/h for 3 days (i.e., 3.6 μmol total). Robust jumping precipitated by naloxone (1 mg/kg, s.c.) indicated the development of physical dependence. Tolerance to i.c.v., i.t., and i.v. morphine (6.3-, 2.0-, and 4.4-fold, respectively) was observed using the tail flick test. Mice implanted with pellets containing 75 mg morphine for 3 days (i.e., ∼260 μmol total) were also tolerant to morphine (6.5-, 7.5- and 18-fold, respectively). Thus, the tolerance developed using the two methods was not identical. These results allow comparison of morphine tested by 3 different routes (i.c.v., i.t., and i.v.) after chronic morphine treatment by two routes (i.c.v. and s.c.) in a single study.
Keywords: Intracerebroventricular; Osmotic minipump; Morphine pellet; Chronic; Naloxone; Withdrawal; Tolerance; (Mice);
Up-regulation of nicotinic acetylcholine receptors by central-type acetylcholinesterase inhibitors in rat cortical neurons by Toshiaki Kume; Mitsuhiro Sugimoto; Yuki Takada; Toshiaki Yamaguchi; Atsushi Yonezawa; Hiroshi Katsuki; Hachiro Sugimoto; Akinori Akaike (77-85).
We previously reported that donepezil, a central-type acetylcholinesterase inhibitor, showed neuroprotective action via α4-and α7-nicotinic acetylcholine receptors against glutamate neurotoxicity in rat cortical culture. The present study was performed to investigate whether the neuroprotective action of acetylcholinesterase inhibitors is accompanied by the alteration of expression and function of nicotinic receptors. Four days treatment with acetylcholinesterase inhibitors (10 μM) enhanced the nicotine-induced increase of the intracellular calcium concentration. Immunoblot analysis revealed that donepezil increased both α4 and α7 subunit proteins. Donepezil and galanthamine increased the number of cells expressing α4- and α7-nicotinic receptors in immunocytochemical analysis. We examined whether up-regulation of nicotinic receptors affected the neuroprotective action of acetylcholinesterase inhibitors. Under up-regulating conditions, donepezil and galanthamine exerted neuroprotective action at lower concentrations. These results suggest that donepezil and galanthamine up-regulate nicotinic receptors in cortical neurons, and that the up-regulation of nicotinic receptors may make cortical neurons more sensitive to the neuroprotective action of donepezil and galanthamine.
Keywords: Acetylcholinesterase inhibitor; Nicotinic acetylcholine receptor; Up-regulation; Neuroprotection; Alzheimer's disease;
The selective tachykinin neurokinin 1 (NK1) receptor antagonist, GR 205,171, stereospecifically inhibits light-induced phase advances of hamster circadian activity rhythms by Robert L. Gannon; Mark J. Millan (86-93).
Circadian rhythms in mammals are generated by master pacemaker cells located within the suprachiasmatic nucleus of the hypothalamus. In hamsters, the suprachiasmatic nucleus contains a small collection of cells immunoreactive for substance P, the endogenous ligand of tachykinin neurokinin 1 (NK1) receptors. In addition, two other nuclei which form part of the circadian system, the intergeniculate leaflet of the thalamus and the raphe nuclei, also contain fibers and/or cell bodies immunoreactive for substance P. In light of these observations, we evaluated the influence of the selective tachykinin NK1 receptor antagonist, GR 205,171, upon circadian activity rhythms in the hamster. Systemic injection of GR 205,171 dose-dependently (2.5–40.0 mg/kg, i.p.) inhibited light-induced phase advances in hamster circadian wheel running activity rhythms by approximately 50%. In contrast, GR 226,206, the less active enantiomer of GR 205,171, failed to affect light-induced phase advances. In addition, we examined the potential ability of GR 205,171 to induce non-photic phase shifts in hamster wheel running rhythms when injected at mid-day to late night circadian times. However, GR 205,171 (40 mg/kg) did not elicit non-photic phase shifts at these times indicating that tachykinin NK1 receptor antagonists are only effective when a light stimulus is applied to the pacemaker. Although GR 205,171 may, in theory, activate several sites within the circadian system, we suggest that GR 205,171 acts in the raphe nuclei to increase inhibitory serotonergic input to pacemaker cells in the suprachiasmatic nuclei, thereby suppressing photic modulation of the pacemaker. These findings have important implications for the use of tachykinin NK1 receptor antagonists in the treatment of depression and other central nervous system disorders.
Keywords: Circadian; Suprachiasmatic; Neurokinin; Raphe; Depression;
Ionotropic glutamatergic neurotransmission in the ventral tegmental area modulates ΔFosB expression in the nucleus accumbens and abstinence syndrome in morphine withdrawal rats by Hui-Ling Wang; Xiao-Hui Xiang; Yuan Guo; Wei-Ran Wu; Dong-Yuan Cao; Hui-Sheng Wang; Yan Zhao (94-104).
The present study sought to assess whether the blockade of ionotropic glutamate receptors in the ventral tegmental area could modulate morphine withdrawal in morphine-dependent rats and the expression of stable ΔFosB isoforms in the nucleus accumbens during morphine withdrawal. Rats were injected (i.p.) with increasing doses of morphine for 1 week to develop physical dependence, and withdrawal was then precipitated by one injection of naloxone (2 mg/kg, i.p.). Abstinence signs such as jumping, wet-dog shake, writhing posture, weight loss, and Gellert-Holtzman scale score were recorded to evaluate naloxone-induced morphine withdrawal. Two ionotropic glutamate receptor antagonists, dizocilpine (MK-801) and 6, 7-dinitroquinnoxaline-2, 3-dione (DNQX), were microinjected unilaterally into the ventral tegmental area 30 min before naloxone precipitation. A second injection of naloxone (2 mg/kg i.p.) was given 1 h after the first naloxone injection to sustain a maximal level of withdrawal so that the expression of stable ΔFosB isoforms in the nucleus accumbens could be measured. This would enable determination of the correlation between the MK-801 or DNQX-induced decrease in somatic withdrawal signs and the change in neuronal activity in the nucleus accumbens. The results showed that both MK-801 and DNQX significantly alleviated all symptoms of morphine withdrawal except for weight loss and reduced the expression of stable ΔFosB isoforms within the nucleus accumbens. These data suggest that ionotropic glutamatergic neurotransmission in the ventral tegmental area regulates the levels of stable ΔFosB isoforms in the nucleus accumbens, which play a very important role in modulating opiate withdrawal.
Keywords: Morphine withdrawal; ΔFosB; Glutamate receptor; DNQX; MK-801; Nucleus accumbens; Ventral tegmental area;
Stimulation of 5-HT1A receptors increases the seizure threshold for picrotoxin in mice by Danka Peričić; Josipa Lazić; Maja Jazvinšćak Jembrek; Dubravka Švob Štrac (105-110).
To evaluate the possible role of 5-HT1A and 5-HT2A receptors in the anticonvulsant effect of swim stress, mice were pre-treated with agonists and antagonists of these receptors prior to exposure to stress and the intravenous infusion of picrotoxin. 8-OH-DPAT ((±)-8-hydroxy-2-(di-n-propylamino) tetralin) and WAY-100635 (a selective agonist and antagonist of 5-HT1A receptors), DOI (1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane) and ketanserin (a 5-HT2A/2C receptor agonist and antagonist) were used. Results demonstrated that 1 and 3 mg/kg of 8-OH-DPAT increased the doses of picrotoxin producing running/bouncing clonus, tonic hindlimb extension and death in stressed and unstressed mice, respectively. Pre-treatment with WAY (0.3 mg/kg) prevented the effect of 8-OH-DPAT (3 mg/kg). DOI (2.5 mg/kg) and ketanserin (1 mg/kg) failed to affect the seizure threshold for picrotoxin. The results show that stimulation of 5-HT1A receptors exerts anticonvulsant actions in stressed and unstressed mice, while stimulation of 5-HT2A/2C receptors does not interfere with the effect of stress on picrotoxin-induced convulsions.
Keywords: Swim stress; Convulsions; (±)-8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide (8-OH-DPAT); WAY-100635; 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI); Ketanserin;
FK962, a novel enhancer of somatostatin release, exerts cognitive-enhancing actions in rats by Kenichi Tokita; Tatsuo Inoue; Shunji Yamazaki; Feng Wang; Takayuki Yamaji; Nobuya Matsuoka; Seitaro Mutoh (111-120).
FK962 (N-(1-acetylpiperidin-4-yl)-4-fluorobenzamide) is a derivative of FK960 (N-(4-acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate), with putative anti-dementia properties. Here, we wanted to determine whether FK962 retained the ability of the parent compound to both facilitate somatostatinergic nerve activity in hippocampal neurons and to ameliorate cognitive dysfunction in rat models. FK962 (10−9–10− 6 M) significantly enhanced high K+-evoked somatostatin release from rat hippocampal slices. FK962 also significantly reduced somatostatin-induced inhibition of Ca2+ channels at 10− 9–10− 7 M in single rat hippocampal neurons using whole-cell patch-clamp. Furthermore, administration of FK962 (0.032–3.2 mg/kg, i.p.) significantly ameliorated memory deficits in passive avoidance task in animal models: scopolamine-treated rats, nucleus basalis magnocellularis-lesioned rats and aged rats. FK962 (0.01–1 mg/kg, i.p.) significantly improved spatial memory deficits induced by nucleus basalis magnocellularis-lesion in water maze task. These results suggest that FK962 ameliorates cognitive impairment in rats via activation of the somatostatinergic nervous system in the hippocampus, indicating that FK962 could be a potent cognitive enhancer and therefore might be of therapeutic value for cognitive disorders such as Alzheimer's disease.
Keywords: FK962; Memory; Passive avoidance; Somatostatin; Water maze; Whole-cell patch-clamp;
Training does not affect the alteration in pulmonary artery vasoreactivity in pulmonary hypertensive rats by Lucie Goret; Cyril Reboul; Stephane Tanguy; Michel Dauzat; Philippe Obert (121-128).
This study examined the effects of training on intrinsic vasorelaxation and vasoconstriction properties of pulmonary hypertensive rat arteries. Fifty seven male Wistar rats were randomly assigned to 4 groups: normotensive sedentary (n = 14), normotensive trained (n = 15), pulmonary hypertensive sedentary (n = 15) and pulmonary hypertensive trained (n = 13). Pulmonary hypertension was obtained using a chronic hypoxia exposure model. Endothelium-dependent vasorelaxation to acetylcholine (10− 8–10− 4 M), endothelium-independent vasorelaxation to sodium nitro-prusside (10− 8–10− 4 M), and vasoconstriction to epinephrine (10− 9–10− 4 M) and endothelin-1 (10− 12–10− 7 M) were assessed on isolated rings of large pulmonary arteries. Alterations in endothelium-dependent and -independent vasorelaxation properties as well as enhanced vasoconstrictor responses were obtained in pulmonary hypertensive rats. Chronic exercise did not affect those pulmonary vasoreactivity alterations. A predominant effect of chronic hypoxia over training seems to be partially responsible for this phenomenon, probably through impairment in nitric oxide bioavailability and vascular smooth muscle sensitivity.
Keywords: Pulmonary hypertension; Chronic exercise; Vasorelaxation; Vasoconstriction;
Effects of fasudil, a Rho-kinase inhibitor, on myocardial preconditioning in anesthetized rats by Şeniz Demiryürek; Ali F. Kara; Ahmet Çelik; Aydan Babül; Mehmet Tarakçıogˇlu; Abdullah T. Demiryürek (129-140).
The aim of this study was to examine the effects of fasudil, a Rho-kinase inhibitor, on ischemic preconditioning and carbachol preconditioning in anesthetized rats. The total number of ventricular ectopic beats was markedly augmented with fasudil at 0.3 mg/kg and depressed with fasudil at 10 mg/kg. Fasudil at 10 mg/kg also markedly decreased the ventricular tachycardia incidence. Ischemic preconditioning, induced by 5 min coronary artery occlusion and 5 min reperfusion, decreased the incidence of ventricular tachycardia and abolished the occurrence of ventricular fibrillation. The incidences of ventricular tachycardia and ventricular fibrillation in the fasudil (10 mg/kg) + ischemic preconditioning group were found to be similar to the ischemic preconditioning group. However, low doses of fasudil (0.3 and 1 mg/kg) appeared to prevent the antiarrhythmic effects of ischemic preconditioning. Carbachol (4 μg/kg/min for 5 min) induced marked reductions in mean arterial blood pressure, heart rate and abolished ventricular tachycardia. Marked reductions in ventricular ectopic beats and ventricular tachycardia were noted in the fasudil (10 mg/kg) + carbachol preconditioning group. Lactate levels were markedly reduced in the ischemic preconditioning group and this reduction was prominently inhibited with fasudil at 1 mg/kg. Ischemic preconditioning caused a marked decrease in plasma malondialdehyde levels. Fasudil (10 mg/kg), ischemic preconditioning and carbachol preconditioning each generated marked reductions in ischemic myocardial malondialdehyde levels. Decreases in infarct size were observed with fasudil (10 mg/kg) treatment, ischemic preconditioning and carbachol preconditioning when compared to control. These results suggest that low doses of fasudil (0.3 and 1 mg/kg) appeared to prevents the effects of ischemic preconditioning and carbachol preconditioning, but a high dose of fasudil (10 mg/kg) was able to produce cardioprotective effects on myocardium against arrhythmias, infarct size or biochemical parameters and mimic the effects of ischemic preconditioning in anesthetized rats.
Keywords: Arrhythmia; Fasudil; Infarct size; Preconditioning; Rho-kinase;
Hydrochlorothiazide increases plasma or tissue angiotensin-converting enzyme-inhibitor drug levels in rats with myocardial infarction: Differential effects on lisinopril and zofenopril by Bart Westendorp; Regien G. Schoemaker; Wiek H. van Gilst; Dirk J. van Veldhuisen; Hendrik Buikema (141-149).
Sodium depletion with diuretics augments the efficacy of angiotensin-converting enzyme-inhibitor therapy for hypertension and renal dysfunction, and possibly for left ventricular dysfunction after myocardial infarction. Underlying mechanisms may involve altered angiotensin-converting enzyme-inhibitor pharmacokinetics. We hypothesized that the diuretic hydrochlorothiazide causes increased steady-state levels of the angiotensin-converting enzyme-inhibitors lisinopril and zofenopril in rats with myocardial infarction. Rats were subjected to coronary ligation to induce myocardial infarction. After 1 week, rats were randomized to 50 mg/kg/day hydrochlorothiazide or control treatment for 3 weeks. The last week, rats received lisinopril or zofenopril in equipotentent dosages (3.3 and 10 mg/kg/day, respectively). Rats were sacrificed at T max after the last dose of angiotensin-converting enzyme-inhibitor, and tissues were collected for analysis of drug concentrations. Lisinopril concentrations in plasma were significantly increased by hydrochlorothiazide, at unchanged tissue concentrations. This increase could be fully explained by decreased renal function, as evidenced by increased plasma creatinine levels (lisinopril + hydrochlorothiazide 82 ± 5 μM versus lisinopril 61 ± 5 μM, P < 0.001). In contrast, zofenoprilat levels in kidney and non-infarcted left ventricle were markedly increased by hydrochlorothiazide, whereas plasma concentrations were unchanged. Although hydrochlorothiazide tended to increase plasma creatinine in zofenopril-treated rats as well, this increase was less pronounced (zofenopril + hydrochlorothiazide 61 ± 3 μM versus zofenopril 54 ± 2 μM, P = 0.15). Hydrochlorothiazide increases steady-state angiotensin-converting enzyme-inhibitor drug levels, most likely by affecting their renal clearance. Notably, the lipophilic angiotensin-converting enzyme-inhibitor zofenopril accumulated in tissue, whereas the hydrophilic lisinopril increased in plasma. Whether combining different angiotensin-converting enzyme-inhibitors with hydrochlorothiazide translates into distinct clinical profiles requires further study.
Keywords: Myocardial infarction; Angiotensin-converting enzyme inhibition; Diuretic; Pharmacokinetics;
The cysteinyl-leukotriene-1 receptor antagonist zafirlukast is a potent secretagogue in rat and human airways by Rene Schmidt; Petra Staats; David A. Groneberg; Ulrich Wagner (150-156).
Cysteinyl-leukotriene-1 receptor antagonists are important tools in the therapy of asthma. Although many studies have been performed concerning their effects on airway smooth muscle tone, there are no basic data on their effects on airway secretions. Therefore, we assessed the effects of zafirlukast and montelukast on rat tracheal secretion by quantification of secreted 35S04 labelled mucus macromolecules, and determined the influence of the arachidonic acid pathway using the modified Ussing chamber technique.Zafirlukast (432 ± 89.99%) and montelukast (167 ± 16.74%) stimulated rat tracheal secretion. This was abolished by application of eicosatetraenoic acid, an inhibitor of the arachidonic acid metabolism. Whereas inhibition of cyclooxygenase did not show any significant effect on zafirlukast induced secretion, blockade of the 5-lipoxygenase pathway markedly reduced the secretagogue effects. Furthermore, inhibition of phosphatidylinositol-3-kinase completely inhibited the effects elicited by zafirlukast. Additional experiments revealed secretagogue effects of zafirlukast also in human bronchial tissue.In conclusion, zafirlukast is a potent inducer of tracheal secretion. Obviously, these effects are induced by involvement of a phosphatidylinositol-3-kinase dependent pathway mediated by products of the arachidonic acid metabolism.
Keywords: Leukotriene receptor antagonist; Airway mucus; Secretion; Asthma; COPD (chronic obstructive pulmonary disease);
Nandrolone treatment decreases the α1B-adrenoceptor mRNA level in rat kidney, but not the density of α1B-adrenoceptors in cultured MDCK-D1 kidney cells by Jonas Lindblom; Ramona Petrovska; Mathias Hallberg; Kristina Magnusson; Fred Nyberg; Staffan Uhlén (157-162).
We have previously shown that treatment of rats with the anabolic androgen steroid nandrolone decreased the density of α1B-adrenoceptors in the rat kidney [Uhlén, S., Lindblom, J., Kindlundh, A., Muhisha, P., Nyberg, F., (2003). Nandrolone treatment decreases the level of rat kidney α1B-adrenoceptors. Naunyn-Schmiedeberg's Arch. Pharmacol. 368, 91–98]. This effect may have been caused either by decreased de novo synthesis of α1B-adrenoceptors or by increased degradation of ars-adrenoceptors. In the present study, we show that treatment of rats with nandrolone decreases the level of mRNA for the α1B-adrenoceptor in the kidneys, implying decreased synthesis of α1B-adrenoceptors. On the other hand, nandrolone did not decrease the density of α1B-adrenoceptors in Madin-Darby Canine Kidney (MDCK) cells, even though the sub-cell line tested, MDCK-D1, expresses both the androgen receptor and the α1B-adrenoceptor. It is concluded that the regulation of α1B-adrenoceptor expression by anabolic androgenic steroids is intricate and cell-type specific.
Keywords: Kidney; α1B-adrenoceptor; Nandrolone; MDCK-D1;
Treatment with PARP-1 inhibitors, GPI 15427 or GPI 16539, ameliorates intestinal damage in rat models of colitis and shock by Rosanna Di Paola; Emanuela Mazzon; Weizheng Xu; Tiziana Genovese; Dana Ferrraris; Carmelo Muià; Concetta Crisafulli; Jie Zhang; Salvatore Cuzzocrea (163-171).
Poly (ADP-ribose) polymerase-1 (PARP-1), a nuclear enzyme activated by DNA strand breaks, plays a detrimental role during inflammation. As inflammation is important in the development of colitis and ischemia/reperfusion (I/R) injury of the intestine, we investigated the effects of 10-(4-methyl-piperazin-1-ylmethyl)-2H-7-oxa-1,2-diaza-benzo[de]anthracen-3-one (GPI 15427) and 2-(4-methyl-piperazin-1-yl)-5H-benzo[c][1,5]naphthyridin-6-one (GPI 16539), two novel and potent inhibitors of PARP-1, in a rat model of gut injury and inflammation, splanchnic artery occlusion (SAO)shock and dinitrobenzene sulfonic acid (DNBS)-induced colitis. We report here for the first time that post-injury administration of GPI 15427 and GPI 16539 exerts potent anti-inflammatory effects by reducing inflammatory cell infiltration and histological injury, and delaying the development of clinical signs in both in vivo models. Furthermore, GPI 15427 and GPI 16539 treatment diminished the accumulation of poly(ADP-ribose) in the ileum of splanchnic artery occlusion-shocked rats and in the colons of dinitrobenzene sulfonic acid-treated rats. Thus, GPI 15427 and GPI 16539 exhibited anti-inflammation activity against damage caused by intestinal ischemia/reperfusion and colitis. GPI 15427 and GPI 16539 may be useful for treating gut ischemia and inflammation.
Keywords: PARP-1; GPI 15427; GPI 16539; Myeloperoxidase; Colitis; Ischemia/Reperfusion;
Cannabinoid CB2 receptor agonist activity in the hindpaw incision by Christopher J. LaBuda; Michael Koblish; Patrick J. Little (172-174).
The identification of peripherally expressed CB2 receptors and reports that the selective activation of cannabinoid CB2 receptors produces antinociception without traditional cannabinergic side effects suggests that selective cannabinoid CB2 receptor agonists might be useful in the management of pain. In a rat hindpaw incision model, we examined the antiallodynic activity of the selective cannabinoid CB2 receptor agonists AM1241 (3–30 mg/kg i.p.), GW405833 (3–30 mg/kg i.p.), and HU-308 (0.3–30 mg/kg i.p.). The rank order for efficacy in the hindpaw incision model following a dose of 10 mg/kg, i.p. was AM1241 > GW405833 = HU-308, and the selective cannabinoid CB2 receptor antagonist, SR144528, reversed the antiallodynic effect of HU-308. Together, these data suggest that selective cannabinoid CB2 receptor agonists might represent a new class of postoperative analgesics.
Keywords: Cannabinoid; Postoperative pain; Tactile allodynia;
Author index (175-176).
Keyword index (177-180).