alexa Dexmedetomidine inhibits osmotic water permeability in the rat cortical collecting duct.
Microbiology

Microbiology

Journal of Microbial & Biochemical Technology

Author(s): Rouch AJ, Kudo LH, Hbert C

Abstract Share this page

Abstract The purpose of this study was to determine whether the selective alpha-2 agonist dexmedetomidine inhibits basic transport properties in the rat cortical collecting duct (CCD). Sprague-Dawley rat CCDs were isolated and perfused to allow measurement of osmotic water permeability (Pf), transepithelial voltage (Vt) and resistance (Rt). Arginine vasopressin (AVP) increases Pf, hyperpolarizes Vt and decreases Rt in the CCD via stimulation of adenylyl cyclase. Dexmedetomidine at 100 nM added to the basolateral side of the CCD reduced AVP-stimulated Pf by 95\% to 100\%, and the alpha-2 antagonist atipamezole reversed the inhibition. In the presence of the protein kinase C inhibitor staurosporine, dexmedetomidine reduced AVP-stimulated Pf by 70\% to 75\% compared with the complete inhibition without staurosporine. When Pf was increased by the use of the non-hydrolyzable analog of cAMP, 8-chlorophenylthio-cAMP, in lieu of AVP, dexmedetomidine inhibited Pf by approximately 35\%. This demonstrated alpha-2-mediated inhibition of Pf despite the presence of constant cellular cAMP levels. Dexmedetomidine reversed AVP-induced effects on Vt and Rt, indicating inhibition of Na+ transport. Results confirm an alpha-2-mediated mechanism that reduces Na+ and water transport in the CCD and suggest that a cellular messenger other than cAMP is involved. This messenger could be protein kinase C.
This article was published in J Pharmacol Exp Ther and referenced in Journal of Microbial & Biochemical Technology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords