Expression and localization of prostaglandin ep3 receptor mrna in the immature rabbit kidney. Bonilla-Felix, Melvin, and Wei Jiang. Department of Pediatrics, University of Texas-Health Science Center at Houston, Houston, Texas 77030
APStracts 3:0013F, 1996.
Arginine vasopressin (AVP)-stimulated cAMP generation is decreased in the immature collecting duct (CD). This is the result of prostaglandin antagonism, most likely via the inhibitory guanine -nucleotide binding protein (Gi). The EP3 subtype prostaglandin E2 (PGE2) receptor, which is coupled to Gi, could mediate this effect. We studied the developmental expression of EP3 receptor in the rabbit kidney. Higher levels of EP3 mRNA were observed in the immature kidney using three different assays ( (1) reverse transcriptase -polymerase chain reaction (RT-PCR) with internal standard, (2) competitive PCR, and (3) RNase protection assay). The highest levels were observed at 2 weeks of age. RT-PCR from isolated nephron segments detected EP3 mRNA in the medullary thick ascending limb (MTAL), cortical CD (CCD) and inner medullary CD (IMCD) of adults and immature kidneys. We conclude that (a) renal expression of EP3 mRNA is increased in immature kidneys, and (b) EP3 mRNA is localized in the distal nephron. This suggests that EP3 receptor may play a role in the regulation of distal tubular transport during development.

Received 6 February 1995; accepted in final form 18 December
1995.
APS Manuscript Number F36-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 January 96