Enzymatic properties of the enzyme 11 beta-hydroxysteroid dehydrogenase (11-HSD), which confers mineralocorticoid selectivity, have been explored in the aldosterone-sensitive collecting duct (CCD) and the aldosterone-insensitive Pars Recta (PR) of the rat kidney. After incubation of freshly isolated tubular segments with [3H]corticosterone (3H-B) or [3H]dehydrocorticosterone (3H-A), the rate of transformation of 3H-B into 3H-A (dehydrogenase activity), or the reverse reaction (reductase activity) were measured by HPLC, Vmax for dehydrogenase activity was found to be 8- to 10-fold higher in CCD than PR. The enzyme functions over a very wide range (0.1-5000 nM) of corticosterone concentration. In CCD, enzyme kinetics suggest either the presence of two 11-HSD forms, differing by their affinity for corticosterone, or complex kinetics. Addition of NAD or NADP to permeabilized tubules revealed that dehydrogenase activity is NAD-dependent in CCD and NADP-dependent in PR. Cofactor addition was ineffective in intact tubules. CCD exhibited an exclusive dehydrogenase activity, whereas in PR dehydrogenase and reductase activity were found. No regulation of dehydrogenase activity could be evidenced in adrenalectomized rats receiving or not aldosterone, corticosterone or dexamethasone, for 2 h, 3 days or 4 days. We conclude that 11-HSD in the CCD and PR differs by its Vmax and cofactor dependence. Corticosteroid hormones do not influence 11-HSD activity.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0304-4165(94)00173-u | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
MTHFD2 promotes breast cancer cell proliferation through IFRD1 RNA m6A methylation-mediated HDAC3/p53/mTOR pathway.
Neoplasma
December 2024
Department of Pathology and Forensic Medicine, College of Basic Medical Sciences, Dalian Medical University, Dalian, China.
MTHFD2 is highly overexpressed in breast cancer tissues, indicating that it might be used as a target in breast cancer treatment. This study aims to determine the role of MTHFD2 in breast cancer cell proliferation and the molecular pathways involved. In order to investigate MTHFD2 gene expression and its downstream pathways in breast cancer, we started our inquiry with a bioinformatics analysis.
View Article and Find Full Text PDFPhylogenetic position of the subfamily Symphrasinae (Insecta: Neuroptera), its intergeneric relationships and evolution of the raptorial condition within Mantispoidea.
Invertebr Syst
January 2025
Instituto de Biología, UNAM, Departamento de Zoología, Colección Nacional de Insectos, Apartado Postal 70-153, 04510, Ciudad de México, Mexico.
The superfamily Mantispoidea (Insecta: Neuroptera) includes the families Berothidae, Rhachiberothidae and Mantispidae. Among these taxa, the last two are collectively known as Raptorial Mantispoidea due to the presence of grasping forelegs for predatory habits. The Mantispidae classically included the subfamilies Symphrasinae, Drepanicinae, Calomantispinae and Mantispinae, yet recent research challenged this classification scheme as well as the monophyly of this family resulting in Symphrasinae being transferred to Rhachiberothidae.
View Article and Find Full Text PDFFluopyram analogues containing an indole moiety: synthesis, biological activity and molecular docking study.
Mol Divers
January 2025
Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai, People's Republic of China.
Succinate dehydrogenase (SDH) has been identified as one of the ideal targets for the development of novel nematicides. However, the resistance of nematodes to fluopyram, one of the commercialized SDH inhibitors, is becoming a growing concern. Since expanding the structural diversity around an active scaffold is a useful strategy for drug development, herein a series of fluopyram analogues with a broad, biologically relevant indole moiety were synthesized and evaluated for nematicidal activity against C.
View Article and Find Full Text PDFWall shear stress modulates metabolic pathways in endothelial cells.
Metabolomics
January 2025
Laboratory of Applied Mass Spectrometry, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
Introduction: Hemodynamic forces play a crucial role in modulating endothelial cell (EC) behavior, significantly influencing blood vessel responses. While traditional in vitro studies often explore ECs under static conditions, ECs are exposed to various hemodynamic forces in vivo. This study investigates how wall shear stress (WSS) influences EC metabolism, focusing on the interplay between WSS and key metabolic pathways.
View Article and Find Full Text PDFPerformance evaluation of the LIOFeron®TB/LTBI IGRA for screening of paediatric LTBI and tuberculosis.
Eur J Pediatr
January 2025
Infectious Diseases Unit, Department of Health Sciences, Anna Meyer Children's University Hospital, University of Florence, Florence, Italy.
Purpose: High-accuracy diagnostic screening tests for Mycobacterium tuberculosis (MTB) infection are required, primarily to detect patients with latent infections (LTBIs) in order to avoid their progression to active tuberculosis disease. The performance of the novel IGRA LIOFeron®TB/LTBI was evaluated in children. The originality of this test is the new MTB antigen contained (L-alanine dehydrogenase), identified as a tool to differentiate active TB from LTBI infection.
View Article and Find Full Text PDFWant 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!