Quantitative rt-pcr analysis of calcitonin receptor mrnas in the
rat nephron.
Firsov, Dmitri, Anne-Christine Bellanger, Sophie Marsy, and Jean-Marc
Elalouf.
D[acute]epartement de Biologie Cellulaire et Mol[acute]eculaire,
Service de Biologie Cellulaire, CEA Saclay, 91191 Gif-sur-Yvette
Cedex, France
APStracts 2:0097F, 1995.
A quantitative assay based on the method of reverse transcription and
polymerase chain reaction (RT-PCR) was developed to study the
expression of calcitonin (CT) receptors in microdissected rat nephron
segments. Steady-state mRNA levels of two CT receptor spliced
variants (CT1a and CT1b) were measured using a mutant cRNA as
internal standard. CT1a, but not the CT1b isoform, was detected in
the kidney cortex, outer medulla and papilla. Among the tested
segments, predominant expression of CT1a mRNA was found in the
cortical thick ascending limb of Henle's loop (754+/-87 mRNA
molecules/ mm of tubular length (n=8)). Lower expression levels were
measured in the medullary thick ascending limb (460+/-62 molecules/
mm (n=7)) and in the cortical collecting duct (327+/-61 molecules/ mm
(n=6)). A weak expression was also detected in the outer medullary
collecting duct and the glomerulus. No expression was found in the
proximal convoluted tubule, pars recta, thin descending and thin
ascending limb of Henle's loop. We conclude that only the CT1a
receptor mRNA is present in the rat kidney, with a significant level
of expression in the cortical and medullary thick ascending limb and
in the cortical collecting duct.
Received 13 March 1995; accepted in final form 2 June 1995.
APS Manuscript Number F86-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 July 1995.