Studies were conducted to examine the contribution of adrenal 5alpha-reductase to the phenomenon of diminished adrenal "responsiveness" to ACTH after hypophysectomy in rats. Rats hypophysectomized for 1 week secreted small amounts of corticosterone (B), 5alpha-dihydrocorticosterone (DHB) and 3beta,5alpha-tetrahydrocorticosterone (R) acutely after ACTH. Adrenal reductase activity in vitro at that time was high. After replacement with ACTH for 24 h, B,DBH, and R secretion increased slightly. Reductase activity remained high. Treatment with ACTH for 2 days further stimulated secretion of DHB and R but not B. Reductase activity was unaffected. Enzyme activity declined at 3 days concomitant with a proportionately greater increase in B than DHB and R secretion. Only after 7 days of ACTH did B secretion exceed DHB and R output. At that time, reductase activity was still lower. The results establish the functional significance of 5alpha-reductase activity as a regulatory site for the action of ACTH in determining the composition of adrenocortical secretory products in hypophysectomized rats.

Download full-text PDF

Source
http://dx.doi.org/10.1210/endo-96-5-1153DOI Listing

Publication Analysis

Top Keywords

reductase activity
16
adrenal 5alpha-reductase
8
5alpha-reductase activity
8
hypophysectomized rats
8
activity
7
acth
7
role adrenal
4
activity determining
4
determining responsiveness
4
responsiveness hypophysectomized
4

Similar Publications

Background: Multiple sclerosis (MS) is a chronic autoimmune condition that damages the myelin sheath of neurons in the central nervous system, resulting in compromised nerve transmission and motor impairment. The astrocytopathy is considered one of the prominent etiological factor in the pathophysiology of demyelination in MS. The expression level of ceramide synthase-2 (CS-2) is yet to be established in the pathophysiology of astrocytopathy although the derailed ceramide biosynthetic pathways is well demonstrated in the pathophysiology of demyelination.

View Article and Find Full Text PDF

Nanopesticides have been recently introduced as novel pesticides to overcome the drawbacks of using traditional synthetic pesticides. The present study evaluated the acaricidal activity of Copper/Graphene oxide core-shell nanoparticles against two tick species, Rhipicephalus rutilus and Rhipicephalus turanicus. The Copper/Graphene oxide core-shell nanoparticles were synthetized through the solution plasma (SP) method under different conditions.

View Article and Find Full Text PDF

Polycyclic aromatic compounds (PACs) are pervasive environmental contaminants derived from diverse sources including pyrogenic (e.g., combustion processes), petrogenic (e.

View Article and Find Full Text PDF

In vitro comparative analysis of metabolic capabilities and inhibitory profiles of selected CYP2D6 alleles on tramadol metabolism.

Clin Transl Sci

February 2025

Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics and Precision Medicine, University of Florida College of Pharmacy, Gainesville, Florida, USA.

Tramadol, the 41st most prescribed drug in the United States in 2021 is a prodrug activated by CYP2D6, which is highly polymorphic. Previous studies showed enzyme-inhibitor affinity varied between different CYP2D6 allelic variants with dextromethorphan and atomoxetine metabolism. However, no study has compared tramadol metabolism in different CYP2D6 alleles with different CYP2D6 inhibitors.

View Article and Find Full Text PDF

Objective: Myocardial ischemia-reperfusion injury (MIRI) is a highly complex disease with high morbidity and mortality. Studying the molecular mechanism of MIRI and discovering new targets are crucial for the future treatment of MIRI.

Methods: We constructed the MIRI rat model and hypoxia/reoxygenation (H/R) injury cardiomyocytes model.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!