M-chlorophenylpiperazine increases blood pressure and heart rate in pithed and conscious rats.
In pithed rats, m-chlorophenylpiperazine (m-CPP) produced marked, dose-dependent (ED50 = 0.18 mumol) increases in mean arterial blood pressure which peaked within 1 minute and were sustained over 15 minutes. Two serotonin antagonists, metergoline and ritanserin, completely blocked the pressor responses to 2.5 mg/kg m-CPP in pithed adrenal demedullated rats, while alpha-adrenergic blockade by prazosin plus yohimbine was without effect, suggesting that the doubling in blood pressure produced by m-CPP was mediated via serotonin receptors within blood vessels. Somewhat smaller increases in blood pressure over baseline values were observed after m-CPP administration to conscious, freely moving rats. A small but statistically significant increase in heart rate peaked 5 minutes after m-CPP and also was blocked by metergoline but was only minimally affected by ritanserin or the prazosin-yohimbine combination. These results with m-CPP support other evidence for two or more separable effects of serotonergic agonists on the peripheral cardiovascular system.
D000313:Adrenal Medulla / Q000502:physiology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D001921:Brain / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects*; D007700:Kinetics; D008297:Male; D008711:Metergoline / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D016713:Ritanserin; D012702:Serotonin Antagonists / Q000494:pharmacology; D013116:Spinal Cord / Q000502:physiology
D010879:Piperazines; D010880:Piperidines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D016713:Ritanserin; D008711:Metergoline; C015068:1-(3-chlorophenyl)piperazine