Further evidence that the tachycardiac response to 5-hydroxytryptamine in rats is not mediated via typical 5-HT2 receptors.
1. In pithed rats, the receptor type of cardiac tissue mediating the tachycardiac response to 5-hydroxytryptamine (5-HT) was analysed. 2. Ketanserin, mesulergine and methiothepin, administered in doses which antagonized the pressor response to 5-HT, slightly reduced, considerably reduced and antagonized, respectively, its tachycardiac response. 3. 8-OH DPAT and RU 24969 produced no significant tachycardia, while DOI neither mimicked nor blocked the 5-HT-induced tachycardia. 4. The tachycardia was not affected by MDL 72222, metoclopramide and cocaine. 5. The hypothesis is proposed that in rats the tachycardiac response to 5-HT is mediated via 5-HT receptors belonging to an yet unclassified subtype of 5-HT1 or 5-HT2 receptors.
Department of Pharmacology, Faculty of Medicine, Belgrade, Serbia.
M K
MK
Krstić
Z S
ZS
Katusić
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004873:Ergolines / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008719:Methiothepin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*
D004873:Ergolines; D011985:Receptors, Serotonin; D012701:Serotonin; D008719:Methiothepin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D007650:Ketanserin; C031649:mesulergine