Antihypertensive effects of ketanserin and ritanserin in the spontaneously hypertensive rat.
Acute as well as chronic treatment with ketanserin but not with ritanserin reduced the blood pressure in the spontaneously hypertensive rat, indicating that 5-HT2-receptor blockade alone does not have antihypertensive properties. Whereas the blood pressure reduction to acute administration of ketanserin was directly related to its ability to shift the dose-response curve of phenylephrine (alpha 1-adrenergic blockade), the same relationship was not apparent following chronic treatment with ketanserin. This suggests that the 5-HT2- and alpha 1-blockade may complement each other in reducing the blood pressure, a conclusion supported by the observation that in the conscious rat, 5-HT2-receptor blockade by ritanserin enhanced the hypotensive response to prazosin. However, ritanserin did not influence the ability of prazosin to antagonize pressor responses to phenylephrine in the pithed rat.
Persson
B
B
Department of Pharmacology, University of Göteborg, Sweden.
Gradin
K
K
Pettersson
A
A
Hedner
T
T
D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D007650:Ketanserin / Q000627:therapeutic use*; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D010880:Piperidines / Q000627:therapeutic use*; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D016713:Ritanserin; D012701:Serotonin / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology
D000959:Antihypertensive Agents; D010880:Piperidines; D011942:Receptors, Adrenergic, alpha; D011985:Receptors, Serotonin; D016713:Ritanserin; D010656:Phenylephrine; D012701:Serotonin; D007650:Ketanserin; D011224:Prazosin