Appearance of an arginine vasotocin receptor of large molecular size in the uterus (shell gland) of the hen at oviposition.

The molecular mass of the arginine vasotocin receptor in membrane fractions of the uterus (shell gland) of hens was estimated by autoradiography of [125I]-labelled arginine vasotocin binding protein after SDS-PAGE. A band of approximately 67 kDa was found in all of the samples taken from laying hens before and after oviposition and from nonlaying hens. In addition to this band, another band of approximately 95 kDa was found in samples from laying hens taken immediately before and after oviposition. Both bands were reduced by the presence of unlabelled arginine vasotocin or mesotocin, but the reduction was greater by arginine vasotocin than by mesotocin. These two bands were not reduced by chicken luteinizing hormone-releasing hormone-I (Gln8-GnRH), chicken luteinizing hormone-releasing hormone-II (His5,Trp7,Tyr8-GnRH) and chicken angiotensin-II (Val5-angiotensin-II). The appearance of the arginine vasotocin receptor of the larger molecular size may be related to oviposition in hens.