Vascular actions of neurohypophysial peptides in the flounder

摘要: Free swimming, chronically cannulated flounder have been used to study the blood pressure effects of arginine vasotocin (AVT) and isotocin. The initial fall in dorsal aortic following AVT injection coincided with an increase ventral pressure, suggesting caused constriction arterio-arterial pathway. Ventral increased a dose dependent manner increasing dose. Dorsal also but not manner, effect at higher doses being off set by branchial vasoconstriction. Isotocin due vasoconstriction, no subsequent pressor was seen. Branchial vasoconstriction both teleost neurohypophysial peptides suggests presence peptide receptor(s) gill, although it is unclear as whether this single common receptor or different populations for each peptide. its absence isotocin there may be other types receptors post-branchial vascular beds. actions suggest that these play some role regulation regional flow distribution.