Role of central serotonergic (5-HT2) receptor in blood pressure regulation in rats.
To investigate the role of the serotonergic nervous system in blood pressure regulation, 5 micrograms of 5-hydroxytryptamine (5-HT) was given i.c.v. before and after 1 microgram of i.c.v. xylamidine or 200 micrograms of i.c.v. ketanserin or 200 micrograms of i.v. ketanserin in conscious Wistar Kyoto rats. Also i.v. (0.5, 1, 2 micrograms) or i.c.v. (1 microgram) phenylephrine (PHE) were given before and after 1 microgram of i.c.v. xylamidine. I.c.v. 5-HT elicited a consistent pressor response of approximately 27mmHg and slight decrease in heart rate. MAP and heart rate did not change after xylamidine or ketanserin. Whereas pressor response to i.c.v. 5-HT after i.c.v. ketanserin or i.c.v. xylamidine was suppressed, it did not change after i.v. ketanserin. Neither i.c.v. nor i.v. PHE-induced pressor response was influenced by i.c.v. xylamidine pretreatment. These data suggest that the central 5-HT2 receptor may subserve pressor function in rats.
Kushiro
T
T
Dept. of Cardiology, Surugadai Nihon University Hospital, Tokyo, Japan.
Kurumatani
H
H
Ishii
T
T
Yokoyama
H
H
Koike
J
J
Hatayama
Y
Y
Kobayashi
Y
Y
Kajiwara
N
N
D000578:Amidines / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000502:physiology*; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY; D011985:Receptors, Serotonin / Q000502:physiology*
D000578:Amidines; D011985:Receptors, Serotonin; D007650:Ketanserin; C005894:xylamidine