Ontogeny of no synthase and renin in the juxtaglomerular apparatus
of rat kidney.
Fischer, Evelyne, Jurgen Schnermann, Josie P. Briggs, Wilhelm Kriz,
Pierre Ronco, and Sebastian Bachmann.
Department of Anatomy and Cell Biology I, University of Heidelberg,
Heidelberg, Germany and INSERM U 64, Hopital Tenon, Paris, France
APStracts 2:0011F, 1995.
The presence of NOS in cells of the macula densa (MD) suggests a role
for arginine-derived nitric oxide in tubulovascular information
transfer. To investigate the postnatal development of the neuronal
isoform of NOS and of renin in the kidney, the cellular distribution
of these enzymes was examined in perfusion-fixed kidneys of 2 day, 6
day, and 15 day old rats at both the protein and mRNA level (n=4 per
group). NOS and renin and their mRNA's were localized by
immunohistochemical and in situ hybridization methods. In addition,
NOS levels were assessed by using NADPH diaphorase histochemistry
(NADPH-d). For quantification, the fraction of NOS- and renin
-positive glomeruli as well as the number of NOS-positive MD cells was
evaluated at all stages. Presence of NOS in single cells of the
developing distal tubule was encountered already in the S-shaped
body. Full expression of a NOS signal in macula densa cells was seen
as soon as a glomerular urinary space was developed. Double labeling
with NADPH-d and antibody to Tamm-Horsfall protein (THP) indicated
mutual exclusiveness of NADPH-d positive MD cells and neighboring THP
positive distal tubule cells at all levels of development. The
relative intensity of renin status was 2d>6d>15d, whereas NOS
expression was maximal on postnatal day 6. Our data are consistent
with an involvement of MD NO synthesis in the early organisation of
the JGA during nephronogenesis and suggest an interdependent relation
with renin producing cells.
Received 2 November 1994; accepted in final form 20 December
1994.
APS Manuscript Number F391-4.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 February 1995.