Background and purpose: Activation of post-synaptic 5-HT1A receptors may provide enhanced therapy against depression. We describe the signal transduction profile of F15599, a novel 5-HT1A receptor agonist. ]-GTPgS binding more potently in frontal cortex than raphe. F15599, unlike 5-HT, more potently and efficaciously stimulated Gai than Gao activation. In rat prefrontal cortex (a region expressing post-synaptic 5-HT1A receptors), F15599 potently activated ERK1/2 phosphorylation and strongly induced c-fos mRNA expression. In contrast, in raphe regions (expressing pre-synaptic 5-HT1A receptors) F15599 only weakly or did not induce c-fos mRNA expression. Finally, despite its more modest affinity in vitro, F15599 bound to 5-HT1A receptors in vivo almost as potently as F13714. Conclusions and implications: F15599 showed a distinctive activation profiles for 5-HT1A receptor-mediated signalling pathways, unlike those of reference agonists and consistent with functional selectivity at 5-HT1A receptors. In rat, F15599 potently activated signalling in prefrontal cortex, a feature likely to underlie its beneficial effects in models of depression and cognition.

The use of some of antipsychotic drugs (APDs) in humans has been hampered by the induction of metabolic disorders such as weight gain, dyslipidemia, and diabetes. In primary rat hepatocytes, we investigated the actions of several APDs on lipid and cholesterol metabolism using [(14)C]acetate incorporation, quantitative reverse transcription-polymerase chain reaction, and western blotting. Clozapine and olanzapine, known to have significant metabolic side effects in man, strongly increased de novo lipid and cholesterol synthesis in rat hepatocytes. Haloperidol, which has less impact in metabolic disorders, enhanced lipogenesis without altering cholesterol production. By contrast, quetiapine, which exhibits few metabolic side effects in man, did not affect lipid and cholesterol synthesis. Interestingly, aripiprazole, which has not yet been reported to induce metabolic disorders in humans, strongly decreases cholesterol synthesis. Furthermore, these inductions of lipid and cholesterol synthesis observed with clozapine and olanzapine were also associated with up-regulation of the transcription factors sterol regulatory element-binding protein (SREBP)-1 and/or SREBP-2 and their associated target genes. Part of the APD-induced metabolic disorders in humans may be due to direct effects on liver metabolism. Our model may also be of interest to assess the action of future drugs on metabolic parameters.

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Weight gain and metabolic disturbances, such as dyslipidemia and hyperglycaemia, are common side effects of most antipsychotic drugs, including risperidone. The aim of this study was to investigate the effects of chronic treatment with risperidone on body weight, fat accumulation, liver weight, and hepatic expression of key genes involved in lipid metabolism in female mice. We also addressed the mechanism of risperidone induction of metabolic side effects by exploring its effect on lipid and cholesterol metabolism in primary cultures of rat hepatocytes. Eleven weeks of treatment with long-acting risperidone (12.5 mpk/week) resulted in a significant weight gain associated with an increase of liver and adipose tissue weight. These effects were positively correlated with hepatic mRNA induction of two key genes involved in lipogenesis: sterol regulatory element binding protein-1c (SREBP-1c) and fatty acid synthase (FAS). Furthermore, in line with these in vivo results, risperidone elicited significant inductions of SREBP-1 maturation and FAS mRNA expression in primary cultures of rat hepatocytes associated with an increase of free fatty acid, triacylglycerol, and phospholipid synthesis as assessed by acetate incorporation. The current investigations underscore the usefulness of a mouse model to study the weight gain observed with risperidone treatment in humans. This study shows that risperidone induces similar effects in the liver (in vivo) and in hepatocyte cell cultures (in vitro) on the expression of key genes and/or proteins that control lipid metabolism. This suggests that risperidone could alter lipid metabolism in the liver and induce weight gain in a way that is partly independent of its action on the central nervous system.

BackgroundSickle cell disease (SCD) accounts for 5% of mortality in African children aged < 5 years. Improving the care management and quality of life of patients with SCD requires a reliable diagnosis in resource-limited settings. We assessed the diagnostic accuracy of the rapid Sickle SCAN® point-of-care (POC) test for SCD used in field conditions in two West-African countries.MethodsWe conducted a case-control study in Bamako (Mali) and Lomé (Togo). Known cases of sickle cell disease (HbSS, HbSC), trait (HbAS), HbC heterozygotes (HbAC) and homozygous (HbCC), aged ≥6 months were compared to Controls (HbAA), recruited by convenience. All subjects received both an index rapid POC test and a gold standard (high-performance liquid chromatography in Bamako; capillary electrophoresis in Lomé). Personnel conducting tests were blinded from subjects’ SCD status. Sensitivity and specificity were calculated for each phenotype. Practicality was assessed by local healthcare professionals familiar with national diagnostic methods and their associated constraints.ResultsIn Togo, 209 Cases (45 HbAS, 39 HbAC, 41 HbSS, 44 HbSC and 40 HbCC phenotypes) were compared to 86 Controls (HbAA). 100% sensitivity and specificity were observed for AA Controls and HbCC cases. Estimated sensitivity was 97.7% [95% confidence interval: 88.0–99.9], 97.6% [87.1–99.9%], 95.6% [84.8–99.5%], and 94.9% [82.7–99.4], for HbSC, HbSS, HbAS, and HbAC, respectively. Specificity exceeded 99.2% for all phenotypes. Among 160 cases and 80 controls in Mali, rapid testing was 100% sensitive and specific. Rapid testing was well accepted by local healthcare professionals.ConclusionRapid POC testing is 100% accurate for homozygote healthy people and excellent (Togo) or perfect (Mali) for sickle cell trait and disease patients. In addition to its comparable diagnostic performance, this test is cheaper, easier to implement, and logistically more convenient than the current standard diagnostic methods in use. Its predictive value indicators and diagnostic accuracy in newborns should be further evaluated prior to implementation in large-scale screening programs in resource-limited settings where SCD is prevalent.