ABSTRACT
Background: Central 5-HT and 5-HT serotonergic 2A 2Creceptors are mainly involved in the control ofnigrostriatal and mesolimbic dopaminergic neuronalactivity has been well proved and established. 5-HThas facilitatory effect on stimulated dopamine releaseby stimulating central 5-HT receptors and inhibitory 2Aeffect by stimulating 5-HT receptors. Aim and 2CObjectives: To evaluate 5-HT and 5-HT receptor 2A 2Cblocking activity of Mirtazapine (MIR) and the effectof mirtazapine pre-treatment on Ergometrine (ERG)induced behaviours, Fluoxetine (FLU) induced penileerections and Haloperidol (HAL) induced catalepsy inrats. Material and Methods: Each group wassubdivided into different subgroups consisting 6animals in each. Control group received DimethylSulfoxide (DMSO) and other groups received differentdoses of mirtazapine one hour before ERG/FLU/HAL.Values obtained from control group were comparedwith all remaining groups pre-treatment with differentdoses of MIR. Results: MIR (MIR) at 2.5, 5, 10 and 20mg/kg intraperitoneally (i.p) did not produce any per seeffects. Pre-treatment with 5, 10 and 20 mg/kg i.p. MIRsignificantly antagonised ERG induced behaviours. 5mg/kg i.p. MIR significantly antagonised whereas 10and 20 mg/kg i.p. MIR abolished FLU (10 mg/kg)induced penile erections in rats. MIR 5 and 20 mg/kgi.p. significantly antagonised HAL (1mg/kg) inducedcatalepsy at 1 hr testing time interval while 10 and 20mg/kg MIR significantly antagonised HAL (1 mg/kg)induced catalepsy at 2 hr testing time interval.Conclusion: Our results indicate that MIR at 5, 10 and20 mg/kg possesses 5-HT and 5-HT receptors 2A 2Cblocking activity. At 5, 10 and 20 mg/kg MIR, byblocking central 5-HT receptors predominantly, 2Ccauses release of dopamine from nigrostriataldopaminergic neurons and therefore antagonizes HALinduced catalepsy
ABSTRACT
Background : Nebivolol is a third-generation highly selective b1-blocker with additional endothelial nitric oxide (NO) mediated vasodilating activity. This property may potentiate the blood pressure-lowering effect of Nebivolol. Nebivolol is also claimed to have neutral or favourable effect on carbohydrate metabolism and lipid profile. Therefore this study was conducted to evaluate effects of Nebivolol on different biochemical parameters in essential hypertensive patients. Materials and Methods : 21 newly diagnosed patients of either sex with essential hypertension were included in the study. Patients having co-morbidities e.g. Diabetes mellitus, hyperlipidemia, gout, pregnant females were excluded from the study. Baseline readings of lipid profile, serum electrolytes, fasting blood sugar and uric acid were recorded before starting Nebivolol drug therapy. Same biochemical tests were repeated after six months drug treatment. Results and Observation : After comparing the means there is increase in total cholesterol, LDL, Serum electrolytes, blood sugar levels but this increase is within normal limits and is not statistically significant. While there is decrease in TG level but statistically not significant. No significant change in HDL, uric acid levels. Conclusion : Nebivolol is a unique, highly selective b1-blocker due to its neutral metabolic properties and is potentially safe over conventional b-blockers.