Corticotropin positively regulates its own receptors and cAMP response in cultured bovine adrenal cells

156Citations
Citations of this article
13Readers
Mendeley users who have this article in their library.

Abstract

Bovine fasciculata adrenal cells contain specific high-affinity (K(D) ~ 2.3 ± 0.4 x 10-10 M) and low-capacity (1910 ± 300 sites per cell) corticotropin (ACTH) receptors. Pretreatment of cells with ACTH, caused in a time- (maximum effect at 48 hr) and dose- (ED50 ~ 10-11 M, V(max) = 10-10 to 10-9 M) dependent manner an increase in ACTH binding. This was due to a 4-fold increase in the number of binding sites without modification of the binding affinity. The same pretreatment also enhanced the cAMP response to further ACTH stimulation in a dose-dependent manner (ED50 ~ 10-11 M) and to a lesser extent the response to forskolin. However, pretreatment with higher concentrations of ACTH (10-8 M) reduced the binding and the cAMP response when compared to the effect of 10-9 M. These ACTH effects, which were mimicked by 8-bromoadenosine 3',5'-cyclic monophosphate, required de novo protein synthesis. Pretreatment with 10-13 to 10-11 M ACTH also enhanced the steroidogenic responsiveness to further hormonal stimulation. However, at higher concentrations the hormone induced an apparent steroidogenic desensitization that was probably related to a depletion of endogenous cholesterol, since cortisol production in the presence of 22-(R)-hydroxycholesterol was increased. Neither angiotensin-II nor atrial natriuretic factor alone modified ACTH receptors, but angiotensin-II partially blocked the stimulatory effect of ACTH. Thus, ACTH is one of the few polypeptide hormones having a positive trophic effect on its own receptors and target-cell responsiveness.

Cite

CITATION STYLE

APA

Penhoat, A., Jaillard, C., & Saez, J. M. (1989). Corticotropin positively regulates its own receptors and cAMP response in cultured bovine adrenal cells. Proceedings of the National Academy of Sciences of the United States of America, 86(13), 4978–4981. https://doi.org/10.1073/pnas.86.13.4978

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free