Characterization of vasopressin and oxytocin receptors in an Australian marsupial

Abstract

In this study arginine vasopressin (AVP) and oxytocin (OT) receptors have been characterized in the brushtail possum. AVP receptors were characterized using [3H]AVP and the radioiodinated AVP V(1a) receptor antagonist 125I-labelled [(C6H5-CH2CO)-O-methyl-D-Tyr-Phe-Gln- Asn-Arg-Pro-Arg-Tyr-NH2] while OT receptors were characterized using the radioiodinated OT receptor antagonist 125I-labelled d(CH2)5[Tyr)Me)2,Thr4,Orn8, Tyr-NH29]-vasotocin. The receptor affinities and densities have been compared with the rat AVP and OT receptors. Low densities of OT receptors were present in the possum ovary and kidney. High densities of AVP binding sites were found in the possum adrenal, testis, mesenteric ..