European Neuropsychopharmacology (v.12, #3)
Sertraline treatment of obsessive-compulsive disorder: efficacy and tolerability of a rapid titration regimen by Filippo Bogetto; Umberto Albert; Giuseppe Maina (181-186).
The objective of this study was to compare in a single blind manner, over a period of 12 weeks, the efficacy and tolerability of two different titration regimens of sertraline in the treatment of OCD: 150 mg/day reached at day five from the beginning of therapy (rapid titration regimen) versus 150 mg/day reached at day 15 from the beginning (slow titration regimen). Patients with a DSM-IV diagnosis of OCD and a Y-BOCS greater or equal to 16 were randomly assigned to receive one of the two dosing regimens; an upper target dose of 150 mg/day was selected on the basis of a review of mean dosages used in flexible-dose sertraline studies. The primary efficacy measure was the Y-BOCS, which was completed at baseline and every 2 weeks. Thirty-two patients referred to the Anxiety and Mood Disorders Unit of the University of Turin were included in the study. Seventeen were assigned to the rapidly escalating dose regimen and 15 to the other titration regimen. Twenty-seven (84.4%) patients completed the 12 weeks of the study: 14 (82.4%) patients in the rapid and 13 (86.7%) in the slow titration regimen. The ANOVA analysis showed a significant difference between treatment groups at week 4 and 6 in favor of the rapid titration regimen group; this difference faded afterwards. Both titration regimens were effective in reducing OC symptoms and were well tolerated: no differences in drop-out or in adverse event rates emerged between the two groups. Limitations of the present study are the single-blind design and the lack of power to detect differences in tolerability.
Keywords: Obsessive-compulsive disorder; Sertraline; Rapid titration;
Behavioral and neurochemical effects of dopaminergic drugs in models of brain injury by M. Medico; S. De Vivo; C. Tomasello; M. Grech; A. Nicosia; M. Castorina; M.A. D’Agata; L. Rampello; L. Lempereur; F. Drago (187-194).
The dopaminergic drugs, ropinirole and dihydroergocryptine (DHECP) were injected subcutaneously (s.c.) at doses of 0.5 and 1 mg/kg/day for 7 days into male rats of the Sprague–Dawley strain. The drug pretreatment reverted amnesia induced in rats by hypobaric hypopxia and tested in active and passive avoidance tasks. Furthermore, a partial restoration of memory retention was found in animals with a 2-month brain occlusive ischemia induced by manipulation of the four major arteries of the brain. No major changes were found in spontaneous motor activity, but drug treatment increased ambulation of animals subjected to acute or chronic experimental manipulation. In a model of kainate-induced epilepsy, ropinirole or DHECP did not affect seizure parameters, but reduced mortality rate. At the end of behavioral procedures, in all animals subjected to hypobaric hypoxia or to brain occlusive ischemia glutathione redox index (glutathione reduced/glutathione oxidized ratio) was measured in the frontal cortex, striatum and hippocampus. It was found that experimental models of brain injury were followed by a decrease of reduced glutathione content in all brain areas. The glutathione redox index was augmented by ropinirole or DHECP treatment in all brain areas. These behavioral and neurochemical findings suggest that ropinirole and DHECP may exert either protective activity (as found in animals pretreated with these drugs and exposed to hypobaric hypoxia) or reversal of brain injury (as found in animals treated after two-month occlusive brain ischemia). Thus, both drugs may be studied as therapeutic agents in brain injuries of various origin.
Keywords: Ropinirole; Dihydroergocryptine; Active and passive avoidance; Hypobaric hypoxia; Brain occlusive ischemia; Kainate-induced convulsions; Glutathione redox index;
ApoE genotype influences the biological effect of donepezil on APP metabolism in Alzheimer disease: evidence from a peripheral model by Barbara Borroni; Francesca Colciaghi; Lucia Pastorino; Silvana Archetti; Paola Corsini; Flaminio Cattabeni; Monica Di Luca; Alessandro Padovani (195-200).
Three major amyloid precursor protein (APP) forms with apparent molecular weight ranging from 106 to 130 kDa are present in human platelets. Alzheimer disease (AD) is associated with a decreased APP forms ratio (APPr) between the three major forms. A total of 25 mild to moderate AD patients were investigated. Platelet APPr was studied before and after 30 days of acetylcholinesterase-inhibitor treatment (donepezil, 5 mg daily). Patients were grouped into non-ϵ4 carriers and ϵ4 carriers according to apolipoprotein E (ApoE) genotype. At baseline, all patients showed low APPr levels and no significant difference was found between the two ApoE subgroups. After treatment, although a marked improvement in APPr was observed in most patients, non-ϵ4 carriers displayed a higher increase compared to ϵ4 carriers (P<0.0001). The present study provides evidence that donepezil influences APP metabolism in platelets, and suggests that ApoE genotype might be an important modulating factor for drug responsiveness in AD.
Keywords: Alzheimer disease; Amyloid precursor protein (APP); Donepezil; Apolipoprotein E;
Organotypic rat cerebellar slice culture as a model to analyze the molecular pharmacology of GABAA receptors by Eugen Davids; Wulf Hevers; Kerstin Dämgen; Kehong Zhang; Frank I Tarazi; Hartmut Lüddens (201-208).
The preservation of the neuronal circuitry in rat cerebellar slice cultures provides an advantage in monitoring the development and characterizing the pharmacology of GABAA receptor subtypes. Sprague–Dawley rats, 8–11 days of age, were decapitated, their cerebella were cut into 400-μm slices and transferred into culture dishes. Cell viability and organotypic cerebellar organization of the culture remained well preserved up to 3 weeks. Autoradiographic procedures were introduced in these advanced culture technique and employed [3H]Ro 15-4513 in the absence and presence of 10 μM diazepam to visualize all benzodiazepine (BZD) and diazepam-insensitive (DIS) binding sites, respectively. Since expression of the α6 subunit variant of the GABAA/BZD receptor is restricted to the cerebellar granule cells and the BZD receptor agonist diazepam has very low affinity for this subunit, changes in DIS [3H]Ro 15-4513 binding sites during cultivation time can be attributed to changes in α6 subunit expression. A time-dependent development of total and DIS [3H]Ro 15-4513 binding sites were observed in the culture with a trend towards an increase in GABAA receptor α6 subunit levels during the first week. These findings suggest that explant preparations can be used to examine morphological changes in rat cerebellar slices. In addition, these preparations can be utilized to study the pharmacological effects of GABAA/BZD selective drugs on postnatal development of GABAA receptors in rat cerebellum.
Keywords: Organotypic culture; Rat; Cerebellum; GABAA receptor;
St John’s wort (Hypericum perforatum) modulates evoked potentials in guinea pig hippocampal slices via AMPA and GABA receptors by J.M Langosch; X.-Y Zhou; M Heinen; S Kupferschmid; S.S Chatterjee; M Nöldner; J Walden (209-216).
The effects of an ethanolic extract of the plant Hypericum perforatum L. (St John’s wort) (HYP) and its hydrosoluble fraction (HYPWS) on electrically evoked population spikes and fEPSP were investigated in this study. Concentration dependent (10−6 to 10−4 g/l) excitatory effects were found. Above concentrations of 10−3 g/l, HYP reduced the evoked responses, whereas HYPWS further increased them. Paired pulse facilitation was unaffected with HYPWS (10−4 to 10−2 g/l). The excitatory effects of HYPWS were amplified by the GABAA and GABAB receptor antagonists bicuculline and phaclofen, respectively. These excitations were antagonised by the AMPA receptor antagonist CNQX. Excitations caused by hypericum were not antagonised by the NMDA receptor antagonists D-APV and MK801, the metabotropic glutamate receptor (type I and II) antagonist MCPG, or the L-type calcium channel blocker verapamil. Hypericin and hyperforin, two components of H. perforatum, were found not to be responsible for the excitatory effects of the extract.
Keywords: AMPA; GABA; Hippocampus; Hyperforin; Hypericin; Hypericum perforatum L.;
Marinobufagenin (MBG) suppression of ethanol-seeking behavior is associated with inhibition of brain cortex Na/K-ATPase in mice by Vladimir A. Kashkin; Alexei Y. Bagrov; Olga V. Fedorova; Yakov Y. Bagrov; Natalia I. Agalakova; Nadezhda A. Patkina; Edwin E. Zvartau (217-223).
In the present study the hypothesis was tested that sodium pump ligands (SPL) can modulate alcohol-seeking behavior and that this effect is related to changes in Na/K-ATPase activity in the central nervous system. Mice were tested for initiation of ethanol intravenous self-administration (IVSA) following i.p. pretreatment with vehicle or the endogenous SPL, marinobufagenin (MBG). Drug- and experimentally-naive mice acquired IVSA of 2% ethanol during a single 30-min session. MBG was found to dose-dependently attenuate (1.25–2.5 μg/kg) initiation of ethanol IVSA producing a decrease in the ratio and in the difference between operant responses of response-dependent and yoked animals as well as a decrease in percentage of mice demonstrating ethanol-seeking behavior. Attenuation of the reinforcing effect of ethanol resulting from MBG was associated with brain levels of this steroid capable of concurrently inhibiting Na/K-ATPase in the brain cortex. We hypothesize that endogenous digitalis-like factors could modulate the reinforcing effect of ethanol.
Keywords: Ethanol; Self-administration; Na/K-ATPase; Marinobufagenin; Ouabain;
Niguldipine impairs the protective activity of carbamazepine and phenobarbital in amygdala-kindled seizures in rats by Kinga K Borowicz; Zdzisław Kleinrok; Stanisław J Czuczwar (225-233).
There is evidence that some calcium (Ca2+) channel inhibitors enhance the protective activity of antiepileptic drugs. Since clinical trials have not provided consistent data on this issue, the objective of this study was to evaluate the interaction of a dihydropyridine, niguldipine, with conventional antiepileptics in amygdala-kindled rats. Niguldipine (at 7.5 but not at 5 mg/kg) displayed a significant anticonvulsant effect, as regards seizure and afterdischarge durations in amygdala-kindled convulsions in rats, a model of complex partial seizures. No protective effect was observed when niguldipine (5 mg/kg) was combined with antiepileptics at subeffective doses, i.e. valproate (75 mg/kg), diphenylhydantoin (40 mg/kg), or clonazepam (0.003 mg/kg). Unexpectedly, the combined treatment of niguldipine (5 mg/kg) with carbamazepine (20 mg/kg) or phenobarbital (20 mg/kg) resulted in a proconvulsive action. BAY k-8644 (an L-type Ca2+ channel activator) did not modify the protective activity of niguldipine (7.5 mg/kg) or the opposite action of this dihydropyridine (5 mg/kg) in combinations with carbamazepine or phenobarbital. A pharmacokinetic interaction is not probable since niguldipine did not affect the free plasma levels of the antiepileptics. These data indicate that the opposite actions of niguldipine alone or combined with carbamazepine (or phenobarbital) were not associated with Ca2+ channel blockade. The present results may argue against the use of niguldipine as an adjuvant antiepileptic or for cardiovascular reasons in patients with complex partial seizures.
Keywords: Niguldipine; Calcium channel inhibitor; Antiepileptic drugs; Seizure; Kindling;
Functional genomics and depression research by Mitsuhiko Yamada; Teruhiko Higuchi (235-244).
Although antidepressants have been used clinically for more than 50 years, no consensus has been reached concerning their precise molecular mechanism of action. Functional genomics is a powerful tool that can be used to identify genes affected by antidepressants or by other effective therapeutic manipulations. Using this tool we have previously identified more than 300 cDNA fragments as antidepressant related genes and from these, original cDNA microarrays were developed. Some of these candidate genes may encode common functional molecules induced by chronic antidepressant treatment. Defining the roles of these genes in drug-induced neural plasticity is likely to transform the course of research on the biological basis of depression. Such detailed knowledge will have profound effects on the diagnosis, prevention, and treatment of depression. Novel biological approaches beyond the ‘monoamine hypothesis’ are expected to evoke paradigm shifts in the future of depression research.
Keywords: Antidepressant; ECT; microarray; Neural plasticity; Differential cloning;
The effect of fluvoxamine and sertraline on the opioid withdrawal syndrome: by Alex M. Gray (245-254).
A microdialysis study was undertaken to determine the effect of acute and sub-chronic administration of the selective serotonin reuptake inhibitor, fluvoxamine, and the acute effect of the selective serotonin reuptake inhibitor sertraline, on the naloxone precipitated opioid withdrawal induced increase in hippocampal noradrenaline levels. This study also determined the effect of fluvoxamine and sertraline on opioid withdrawal-induced physical behaviours. Naloxone (1 mg kg−1; i.p.) increased noradrenaline levels in the hippocampus of morphine dependent rats 20 min after administration, with peak levels of 267±13% of baseline, occurring 40 min after administration of naloxone. Opioid withdrawal-induced physical behaviours were evident in morphine dependent rats 5 min after a naloxone injection (1 mg kg−1; i.p.). Acute fluvoxamine or sertraline (10 mg kg−1; i.p.) given 40 min before naloxone (1 mg kg−1; i.p.) did not modify the increased hippocampal noradrenaline levels (242±15 and 242±19%, respectively), observed in morphine dependent rats following an naloxone injection. Acute fluvoxamine and sertraline (10 mg kg−1; i.p.) reduced the severity of the naloxone precipitated opioid withdrawal syndrome. Sub-chronic treatment with fluvoxamine (10 mg kg−1; i.p.) prevented the naloxone precipitated increase in hippocampal noradrenaline levels in morphine dependent rats. Furthermore, sub-chronic fluvoxamine produced a significantly reduced baseline level of noradrenaline in these rats which was 52.5±8% of baseline 40 min after naloxone
Keywords: Opioid withdrawal; Drug dependence; Noradrenaline; Antidepressants; Locus coeruleus; Paragigantocellularis; Limbic system; Morphine; Fluvoxamine; Sertraline;
Carbamazepine augmentation in depressive patients non-responding to citalopram: a pharmacokinetic and clinical pilot study by Lina Steinacher; Pierre Vandel; Daniele F. Zullino; Chin B. Eap; Marlyse Brawand-Amey; Pierre Baumann (255-260).
Citalopram is a chiral antidepressant drug. Its eutomer, S-citalopram (escitalopram), has recently been introduced as an antidepressant. In an open pilot study, four outpatients and two inpatients with a major depressive episode (ICD-10), and who were nonresponders to a 4-week pretreatment with 40–60 mg/day citalopram, were comedicated for another 4-week period with carbamazepine (200–400 mg/day). Some of the patients suffered also from comorbidities: Phobic anxiety disorder with panic attacks (n=2), generalised anxiety disorder, alcohol abuse, dependent personality disorder, hypertension (n=1). After a 4-week augmentation therapy with carbamazepine, a significant (P<0.03) decrease of the plasma concentrations of S-citalopram and R-citalopram, by 27 and 31%, respectively, was observed. Apparently, the probable induction of CYP3A4 by carbamazepine results in a nonstereoselective increase in N-demethylation of citalopram. Moreover, there was a significant (P<0.03) decrease of the ratio S/R-citalopram propionic acid derivative, the formation of it being partly regulated by MAO-A and MAO-B. Already, within 1 week after addition of carbamazepine, there was a slight but significant (P<0.03) decrease of the MADRS depression scores, from 27.0±7.7 (mean±S.D.) to 23.3±6.6, and the final score on day 56 was 18.8±10.9. The treatment was generally well tolerated. There was no evidence of occurrence of a serotonin syndrome. After augmentation with carbamazepine, treatment related adverse events were: Nausea in one case, diarrhea in one case, and rash in two cases. In conclusion, the results of this pilot study suggest that carbamazepine augmentation of a citalopram treatment in previous nonresponders to citalopram may be clinically useful, but that in addition carbamazepine can lead to a decrease of the plasma concentrations of the active enantiomer escitalopram.
Keywords: Depression; Citalopram; Carbamazepine–Augmentation; Pharmacokinetic interaction; Cytochrome P-450; Escitalopram;
Chronic clozapine, but not haloperidol, treatment affects rat brain vesicular monoamine transporter 2 by Moshe Rehavi; Netta Roz; Abraham Weizman (261-268).
We compared the effect of chronic clozapine and haloperidol treatment on the expression of rat brain vesicular monoamine transporter (VMAT2) as well as on the membranal presynaptic transporters for serotonin, dopamine and noradrenaline. Rats were treated for 21 days with clozapine (25 mg/kg), haloperidol (0.5 mg/kg) or saline. VMAT2 expression was assessed on the protein level by high affinity [3H]dihydrotetrabenazine binding using autoradiography, and on the mRNA level by in situ hybridization. The densities of the monoamine transporters were evaluated by autoradiography using specific ligands. Clozapine administration led to an increase in [3H]TBZOH binding in the nucleus accumbens, prefrontal cortex and striatum, whereas haloperidol had no effect on VMAT2 binding capacity. The clozapine-induced increase in VMAT2 was accompanied by a parallel increase in the membrane serotonin transporter in the prefrontal cortex and the striatum. Haloperidol induced an increase in the serotonin transporter in the striatum and the core of the nucleus accumbens. The special effect of clozapine on VMAT2 expression may be relevant to its unique therapeutic advantages.
Keywords: Vesicular monoamine transporter; Clozapine; Haloperidol; Dopamine transporter; Serotonin transporter; Noradrenaline transporter;
Elevated serum S100B protein in drug-free bipolar patients during first manic episode: a pilot study by R. Machado-Vieira; D.R. Lara; L.V.C. Portela; C.A. Gonçalves; J.C. Soares; F. Kapczinski; D.O. Souza (269-272).
S100B protein is a calcium-binding protein mostly derived from glial cells, which exerts trophic or toxic effects on neural cells depending on its concentration. Since serum S100B levels has been tested as a potential marker in neuropsychiatric disorders, and structural abnormalities on glial cells have been recently associated with bipolar disorder patients, we conducted this preliminary study to examine if S100B serum levels are altered during first manic episode. We quantitated S100B in serum of 40 subjects (20 unmedicated patients during manic episode and 20 healthy matched controls). The mean±S.D. values for S100B for bipolar subjects were 0.065±0.068 μg/l and 0.018±0.029 μg/l for healthy controls. Increased levels of S100B in bipolar mania was statistically significant (Wilcoxon signed ranks test, Z=−2.45, P=0.01). These preliminary findings suggest that mania may increase the levels of S100B in serum of bipolar disorder patients, which could be related to adaptative neural mechanisms in bipolar mania.
Keywords: Bipolar disorder; S100B protein; Mania; Serum; Mechanism of action; Glia;