title: Calcitonin receptor binding in the hen anterior pituitary during an oviposition cycle.
abstract: The equilibrium dissociation constant (K(d) ) and the maximum binding capacity (B(max) ) of calcitonin (CT) receptor in the plasma membrane of the anterior pituitary in hens were examined by Scatchard analysis of specific binding of (125) I-labeled chicken CT. Values of K(d) and B(max) of CT receptor were smaller in laying hens than in non-laying hens. A decrease in the K(d) and B(max) value of CT receptor was observed in the anterior pituitary after the injection of estradiol-17β and progesterone into nonlaying hens, but not changed after the injection of 5α-dihydrotestosterone. During an oviposition cycle, the K(d) and the B(max) value decreased 3 h before oviposition. In non-laying hens, neither the K(d) nor the B(max) value changed during a full day period. The present study suggests that the CT action on the anterior pituitary may increase 3 h before oviposition by the effect of estradiol-17β and progesterone in laying hens.
authors.affiliation: The United Graduate School of Agricultural Science Graduate School of Applied Biological Sciences, Gifu University, Yanagido, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakayama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takahashi
authors.forename: Kaori
authors.initials: K
authors.lastname: Nakagawa-Mizuyachi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kawashima
mesh_terms: D000818:Animals; D002116:Calcitonin / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002645:Chickens / Q000502:physiology*; D013196:Dihydrotestosterone / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D010058:Oviposition / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D018003:Receptors, Calcitonin / Q000378:metabolism*; D013997:Time Factors
chemical_list: D018003:Receptors, Calcitonin; D013196:Dihydrotestosterone; D011374:Progesterone; D004958:Estradiol; D002116:Calcitonin