Abstract

Corticotropin releasing hormone (CRH) stimulation of ACTH release and cyclic AMP-mediated events involved in the control of ACTH release were compared in sham-operated and adrenalectomized rats. CRH-stimulated adenylate cyclase activity was decreased in pituitary homogenates from adrenalectomized animals. CRH-stimulated cyclic AMP accumulation was essentially abolished and CRH-stimulated cyclic AMP-dependent protein kinase (A-kinase) activity was decreased in freshly prepared anterior pituitary cells from adrenalectomized animals. Basal and CRH-stimulated ACTH release was elevated in these cells. Since ACTH release is increased in adrenalectomized rats despite the down regulation of CRH-linked pituitary mechanisms, we speculate that the site of action of disinhibition by corticosterone of ACTH release (or synthesis) following adrenalectomy is distal to the generation of cyclic AMP and/or that non-CRH mediated mechanisms assume a greater role in ACTH regulation following adrenalectomy.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.