Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new visken research articles will be listed here shortly after becoming available to us.
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Medical research on visken
Serotonin receptors contribute to the promnesic effects of P. olacoides (Marapuama).
Physiol Behav. 2008 May 1;
da Silva AL, Ferreira JG, da Silva Martins B, Oliveira S, Mai N, Nunes DS, Elisabetsky E
Nootropic, antioxidant, and neuroprotective properties have been shown in a standardized ethanol extract of Ptychopetalum olacoides (POEE), a medicinal plant traditionally used by the Amazonian elderly population. It has been revealed that POEE mechanisms of action include anticholinesterase effects, and involve beta-adrenergic and dopamine D(1) receptors. The purpose of this study was to verify the role of serotonin receptors in the promnesic effects of this standardized extract. The step-down task in mice and selective serotonin antagonists were used. The study reveals that POEE promnesic effects on short-term (acquisition, consolidation and retrieval) and long-term (retrieval) declarative aversive memories are increased by 5HT(2A) (but not 5HT(1A)) serotonin antagonists (spiperone and pindolol, respectively). The observed synergism between POEE and spiperone can be interpreted as the combined effects of two subeffective doses of two 5HT antagonists, or the known synergism between an acetylcholinesterase inhibitor (POEE) and a 5HT antagonist. In conclusion it is suggested that 5HT(2A) serotonin receptors are relevant for the promnesic effects of this extract, adding to its multiple mechanisms of action.
J Chromatogr A. 2008 Jul 4; 1196-1197: 23-7
Abdel-Rehim M, Persson C, Altun Z, Blomberg L
96-well pipette tips with a chemically bonded monolithic methacrylate sorbent plug were used for solid-phase extraction (SPE) of pindolol and metoprolol in human plasma samples. The sorbent plug was formed by in situ polymerization. Monolithic packed 96-tips are a tool for miniaturized, solid-phase extraction. Using such packed 96-tips, a 96-well plate could be handled in about 2min. The key aspect of the monolithic phase is that monolithic material can provide both relatively good binding capacity and relatively low backpressure properties. The validation of the methodology showed that the accuracy values of quality-control samples were between 101% and 103% for metoprolol, while between 94% and 114% for pindolol. The precision ranged from 4% to 15%. The standard calibration curves were obtained within the concentration range 5-5000nM in plasma samples. The coefficients of determination (R(2)) for plasma samples were >/=0.99. Our prepared polymer based monolithic packed 96-tips were compared with commercial silica based 96-tips and protein precipitation.
Pharmacotherapy for Inappropriate Sexual Behaviors in Dementia: A Systematic Review of Literature.
Am J Alzheimers Dis Other Demen. 2008 May 28;
Ozkan B, Wilkins K, Muralee S, Tampi RR
The aim of this study is to systematically review the published literature on pharmacotherapy for inappropriate sexual behaviors in dementia. Literature search of the 5 databases (PubMed, MEDLINE, EMBASE, PsychINFO, and COCHRANE collaboration) and the analysis of the data available for the pharmacotherapeutic treatments of inappropriate sexual behaviors in dementia were carried out.There are no published randomized controlled trials of pharmacotherapy for inappropriate sexual behaviors in dementia, but available data from uncontrolled trials, case series, and individual case reports suggest efficacy for antidepressants, antipsychotics, mood stabilizers, hormonal agents, cimetidine, and pindolol for the treatment of these behaviors. Although there are no controlled data for the treatment of inappropriate sexual behaviors in dementia, available data suggest efficacy for some commonly used pharmacotherapeutic agents.
Regul Pept. 2008 Jun 5; 148(1-3): 1-5
Radács M, Gálfi M, Nagyéri G, Molnár AH, Varga C, László F, László FA
The effects of adrenaline (A) and noradrenaline (NA) on vasopressin (VP) secretion were studied in 13-14-day cultures of isolated rat neurohypophyseal (NH) tissue. The VP contents of the supernatant media were determined by radioimmunoassay after a 1 or 2-h incubation. Significantly increased VP levels were detected in the tissue culture media following the administration of A (an alpha+beta(2)-receptor agonist), depending on the dose of A. The VP secretion elevation was totally blocked by the previous administration of phentolamine (an alpha(1)+alpha(2)-receptor antagonist) or corynanthine (an alpha(1)-receptor antagonist). Yohimbine (an alpha(2)-receptor antagonist) did not influence the VP secretion increase induced by A. After the administration of NA (a beta+alpha(1)-receptor agonist), a VP secretion elevation was again detected, but the degree of enhancement proved smaller than that of the VP secretion increase induced by A. Propranolol (a beta(1)+beta(2)-receptor antagonist) before NA administration prevented the VP secretion increase. Atenolol (a beta(1)-receptor antagonist) did not block the VP secretion elevation induced by NA. Corynanthine (an alpha(1)-receptor antagonist) treatment before NA administration reduced the NA-induced VP enhancement, because NA has an alpha(1)-receptor agonist character in addition to its main character (a beta-receptor agonist). Surprisingly, the administration of pindolol (a beta(1)+beta(2)-receptor antagonist) enhanced VP secretion. This contradictory effect can be explained in that pindolol not only acts as a blocker, but also exerts "intrinsic sympathomimetic action" and a strong adrenergic agonist effect. Pindolol before NA administration significantly increased the NA-induced VP elevation. CONCLUSIONS: Mainly the alpha(1)- and beta(2)-adrenergic receptors are involved in the A- or NA-induced increase of VP secretion in isolated NH tissue cultures. The results indicate that VP release is influenced directly by the adrenergic system, and the adrenergic control of VP secretion from the NH tissue in rats can occur at the level of the posterior pituitary.
Study on chiral resolution of three beta-blockers by affinity electrokinetic chromatography.
Talanta. 2008 Mar 15; 75(1): 222-6
Yang G, Zhao Y, Li M, Zhu Z, Zhuang Q
The chiral resolution of three beta-blockers including propranolol, pindolol and oxprenolol, was studied by affinity electrokinetic chromatography. The effect of various chiral selectors and some key parameters including buffer pH, buffer concentration, capillary temperature and applied voltage were carefully studied, respectively. At optimum condition, based on the signal-to-noise ratio of 3, the detection limits for the simple resolution and chiral resolution were found to be 1.0x10(-5) and 4.0 x 10(-5)M, respectively. In addition, the interactions of these beta-blockers with bovine serum albumin (BSA) were studied and the binding constant (K(a)) between BSA and each of beta-blockers were calculated. Based on linear correlation coefficient, it can be concluded that the binding ratio of pindolol (oxprenolol) combining with BSA is 1:1, and that the binding number of propranolol interacting with BSA deviates one.
Serotonin transporter gene and response to lithium augmentation in depression.
Psychiatr Genet. 2008 Apr; 18(2): 92-7
Stamm TJ, Adli M, Kirchheiner J, Smolka MN, Kaiser R, Tremblay PB, Bauer M
BACKGROUND: The serotonin (5-HT) transporter gene-linked polymorphic region (5-HTTLPR) is associated with better response to selective serotonin reuptake inhibitors in Caucasian patients carrying the long (l)-allele. In contrast, augmentation of antidepressant drugs with pindolol has been shown to improve responsiveness to antidepressants in short (s)-allele carriers. Lithium augmentation is a well-established strategy for overcoming treatment resistance. In this study, the 5-HTTLPR allele variant's effect on lithium augmentation was analyzed in antidepressant-nonresponsive patients. METHODS: We measured remission rates during lithium augmentation in 50 depressed patients genotyped for the 5-HTTLPR. All patients took part in phase II of the German Algorithm Project, a prospective study for the evaluation of a standardized stepwise drug treatment regimen. For statistical analysis, the Cox regression model including several clinical factors besides the 5-HTTLPR was used. RESULTS: Only the genotype of the 5-HTTLPR (P
J Clin Psychopharmacol. 2008 Apr; 28(2): 249-51
Benedetti F, Barbini B, Bernasconi A, Fulgosi MC, Campori E, Colombo C, Dallaspezia S, Lorenzi C, Pontiggia A, Radaelli D, Smeraldi E
Toxicol In Vitro. 2008 Jun; 22(4): 1070-6
Cheong HI, Johnson J, Cormier M, Hosseini K
beta-Blockers are a class of agents that have been used extensively in topical preparations for the treatment of glaucoma. Recent evidence indicates that they may also be useful in a number of retinal diseases. Because biocompatibility is of utmost importance in the treatment of ocular-related diseases, we compared the in vitro cytotoxicity, using the MTT assay, of eight clinically available beta-blockers (propranolol, alprenolol, atenolol, labetalol, metoprolol, pindolol, timolol, and bisoprolol) on human corneal epithelial and retinal pigment epithelial cell lines. Primary and immortalized corneal and retinal cell lines were compared for their susceptibility to the cytotoxic effect of the drugs. The cytotoxicity of beta-blockers was also evaluated on human skin keratinocytes and fibroblasts in order to investigate susceptibility differences as a function of the tissue of origin. Results demonstrated large differences in cytotoxicity (about 60-fold) for these closely related drugs on the same cell line. Conversely, only relatively small differences in cytotoxicity were observed between the different cell lines for the same drug, indicating that the mechanism of cytotoxicity is not cell-specific. Calculation of the ratio between the cytotoxicity of beta-blockers and their beta-blocking constant is presented as a potential tool to help identify the least irritating, most potent drug.
J Clin Psychopharmacol. 2008 Feb; 28(1): 39-44
Safarinejad MR
PURPOSE: To evaluate the efficacy and safety of pindolol 7.5 mg/d in delaying of ejaculation in paroxetine-refractory patients. MATERIALS AND METHODS: Eighty-six married men (mean age, 33 years) with premature ejaculation unresponsive to paroxetine 20 mg/d given for 2 months or longer were randomized to receive 7.5 mg pindolol (n = 44) (group 1) (PXT + POL) or placebo (n = 42) (group 2) (PXT + PBO) for 6 weeks, while continuing paroxetine. After 6 weeks, all patients received paroxetine and placebo and were followed for 3 further weeks in a single-blind manner. Pretreatment evaluation included history and physical examination, mean intravaginal ejaculatory latency time (IELT), International Index of Erectile Function (IIEF), and Meares-Stamey test. The efficacy of 2 treatments was assessed every 1 week during treatment and, at the end of study, using responses to IIEF, IELT evaluation, mean intercourse satisfaction domain, mean weekly coitus episodes, and adverse drug effects. RESULTS: Seventy-seven (89.5%) completed the whole treatment schedule. At the end of 6-week treatment period, the IELT after paroxetine-pindolol and paroxetine-placebo gradually increased from mean 48 and 41 seconds to approximately 188 and 58 seconds, respectively (P = 0.001). The mean weekly intercourse episodes increased from pretreatment values of 1.5 and 1.5 to 2.7 and 1.7, for groups PXT + POL and PXT + PBO, respectively (P = 0.01). Baseline mean intercourse satisfaction domain values of IIEF 12 and 11 reached to 16 and 11 at 6-week treatment in PXT + POL and PXT + PBO groups, respectively (P = 0.01). Upon discontinuing pindolol, all outcome measures returned to baseline values rapidly. The incidence of side effects with paroxetine-pindolol was significantly higher (P = 0.04). CONCLUSIONS: These findings support that a single high dose of pindolol (7.5 mg) is an effective augmentation strategy in paroxetine-refractory patients.
Neurogastroenterol Motil. 2008 Jun; 20(6): 680-8
O'Mahony S, Chua AS, Quigley EM, Clarke G, Shanahan F, Keeling PW, Dinan TG
Efforts to define either a biomarker for irritable bowel syndrome (IBS) or a valid animal model have proven disappointing. The aims of this study were to determine if buspirone stimulates prolactin release through the 5-hydroxytryptamine (5HT)1a receptor and whether this response is altered in patients with IBS and in the rat maternal separation model. Buspirone (30 mg) was used to stimulate prolactin release in 40 patients with IBS and in 40 healthy controls. In study 1, 10 IBS patients and 10 controls underwent pretreatment with pindolol (5HT1a antagonist) or placebo followed by buspirone. In study 2, 30 patients with IBS and 30 healthy controls had prolactin release stimulated by buspirone. Maternally separated and nonseparated rats were also treated with buspirone and prolactin monitored. Serotonin metabolites were measured together with the expression of the 5HT1a and serotonin transporter (SERT) gene. Pindolol produced a dose-dependent decrease in the buspirone prolactin response. Patients with IBS and maternally separated rats showed an exaggerated release of prolactin in response to buspirone. In the animal model, an increased turnover of 5HT was found in the brainstem together with a trend toward increased activity of the SERT gene. In conclusion altered central serotonin responses are found in both IBS and in an animal model.