Distribution and regulation of guanylyl cyclase type-b in the rat
nephron.
Dean, Alan D., V. Matti Vehaskari, Detlef Ritter, and James E.
Greenwald.
Departments of Medicine and Molecular Biology and Pharmacology,
Washington University School of Medicine, St. Louis, MO 63110, Renal
Department of Pediatrics, Louisiana State, University Medical Center,
New Orleans, LA 70112, Department of Pathology, St. Louis University
Health Sciences, Center, St. Louis, MO 63104
APStracts 2:0158F, 1995.
C-type natriuretic peptide 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
(5662+/-1622 and 5187+/-1204 molecules of cDNA/_g total RNA,
respectively; mean+/-S.E.M, 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 to
euvolemic controls. Immunohistochemical staining also support 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.
Received 16 March 1995; accepted in final form 18 August 1995.
APS Manuscript Number F91-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.