Increased reactivity in the mesenteric artery of spontaneously hypertensive rats to phorbol ester.
The contraction responses of mesenteric artery from 10 week old spontaneously hypertensive rats (SHRs) and normotensive Wistar Kyoto controls (WKYs) to phorbol 12, 13 - dibutyrate (PDBu) and agents acting on the potential-operated calcium channels were compared. The vessels from the SHR were significantly more sensitive to PDBu than those from the WKY. The PDBu-induced contractions were inhibited by nifedipine. The vessels from the SHR were also more sensitive to Bay K 8644 and KCl than the WKY. Low concentrations of PDBu (1 nM) potentiated the KCl contraction significantly more in the SHR than the WKY. It is suggested that the increased reactivity to PDBu in the SHR may in part be related to changes in the activity of the potential-operated calcium channels.
D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D002273:Carcinogens; D007473:Ion Channels; D010703:Phorbol Esters; D015240:Phorbol 12,13-Dibutyrate