Quantification of nitric oxide synthase activity in microdissected segments of the rat kidney. Am J Physiol 1999 Jun;276(6):F874-81
Date
06/11/1999Pubmed ID
10362776DOI
10.1152/ajprenal.1999.276.6.F874Scopus ID
2-s2.0-0033000931 (requires institutional sign-in at Scopus site) 175 CitationsAbstract
This study was designed to quantify nitric oxide synthase (NOS) activity in microdissected glomeruli (Glm), pars convoluta, pars recta, cortical collecting duct, cortical thick ascending limb, outer medullary collecting duct, medullary thick ascending limb and thin limb, inner medullary collecting duct (IMCD) and thin limb, and vasa recta (VR). Total protein from microdissected segments was incubated with L-[3H]arginine and appropriate cofactors, and the L-arginine and converted L-citrulline were separated by reverse-phase HPLC and radiochemically quantitated. NOS activity was found to be greatest in IMCD (11.5 +/- 1.0 fmol citrulline. mm-1. h-1) and moderate in Glm (1.9 +/- 0.3 fmol. glomerulus-1. h-1) and VR (3.2 +/- 0.8 fmol. mm-1. h-1). All other renal structures studied exhibited significantly less NOS activity. The mRNA for NOS isoforms in the NOS activity-positive segments was then identified by RT-PCR. The IMCD contained mRNA for neuronal (nNOS), endothelial (eNOS), and inducible NOS (iNOS), but Glm and VR only expressed the mRNA for nNOS and eNOS. These experiments demonstrate that the greatest enzymatic activity for NO production in the kidney is in the IMCD, three- to sixfold less activity is present in the Glm and VR, and minimal NOS activity is found in other segments studied.
Author List
Wu F, Park F, Cowley AW Jr, Mattson DLAuthor
Allen W. Cowley Jr PhD Professor in the Physiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsChromatography, High Pressure Liquid
Citrulline
Dissection
In Vitro Techniques
Isoenzymes
Kidney
Kidney Tubules
Male
Nitric Oxide Synthase
RNA, Messenger
Rats
Rats, Sprague-Dawley
Reverse Transcriptase Polymerase Chain Reaction
Time Factors