Distribution and regulation of guanylyl cyclase type B in the rat nephron.
C-type natriuretic peptide (CNP) has been localized to the proximal and distal nephron. In this study, we examined the distribution and regulation of the CNP receptor, guanylyl cyclase type B (GC-B), in the rat kidney. GC-B mRNA was detected most frequently in microdissected glomeruli, thin and thick limbs of the loop of Henle, and outer and inner medullary collecting ducts by reverse transcription-polymerase chain reaction (RT-PCR). This pattern of expression is supported by immunofluorescent staining, using anti-GC-B-specific antiserum. Nearly equivalent levels of GC-B and guanylyl cyclase type A (GC-A) mRNAs were found by quantitative RT-PCR (5,662 +/- 1,622 and 5,187 +/- 1,204 molecules of cDNA/microgram total RNA, respectively; means +/- SE, n = 6). Renal inner medulla GC-B mRNA levels, but not renal CNP mRNA levels, were 3.2-fold greater in hypervolemic and 2.3-fold less in hypovolemic rats compared with euvolemic controls. Immunohistochemical staining also supports a greater GC-B expression with increased volume status. These data link hydration status and GC-B expression and suggest an additional and novel mechanism for regulating intravascular volume.
Dean
A D
AD
Department of Medicine, Washington University School of Medicine, St. Louis 63110, USA. adean@biodec.wustl.edu
Vehaskari
V M
VM
Ritter
D
D
Greenwald
J E
JE
D000818:Animals; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D007158:Immunologic Techniques; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009399:Nephrons / Q000378:metabolism*; D009994:Osmolar Concentration; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D014158:Transcription, Genetic; D014556:Urine / Q000737:chemistry / Q000502:physiology
D007527:Isoenzymes; D012333:RNA, Messenger; D006162:Guanylate Cyclase