Nephrogenesis and angiotensin ii receptor subtypes gene expression
in the fetal lamb..
Gimonet, Val[acute]erie, Laurence Bussieres, Anissa A. Medjebeur,
Bernard Gasser, Brigitte Lelongt, and Kathleen Laborde.
Department of Physiology, Necker-Enfants Malades Hospital, 75015
Paris, France
APStracts 5:0039F, 1998.
To investigate the role of Angiotensin II (AII) in nephrogenesis, a
developmental study of renal AT1 and AT2 receptor mRNA expression was
performed in parallel with the quantitative and qualitative analysis
of metanephros development in fetal lamb from 60 to 140 days of
gestation. Both AII receptor subtypes were expressed early during
nephrogenesis but displayed specific spatial and temporal
distribution during gestation. High AT2 mRNA expression took place in
the outermost nephrogenic area and in the undifferentiated
mesenchymal cells surrounding the ampulla; level of AT2 expression in
this localization followed closely glomeruli proliferation rate and
disappeared after nephrogenesis completion (>120 days). AT2 mRNA
was also detected in the differentiated epithelial cells of macula
densa of maturing glomeruli. Although most of AT1 mRNA labeling was
found in the mesangial cells of maturing glomeruli where it persisted
after nephrogenesis completion, additional labeling was found in
undifferentiated cells: in cells invading the inferior cleft of S
-shaped bodies (80 days) and in medullar cells between tubules (120
days). Our results suggest that each receptor subtype has a specific
role in renal morphogenesis, AT2 in mesenchymal proliferation or
apoptosis, and AT1 in vascular smooth muscle cells differentiation.
Received 2 December 1996; accepted in final form 17 February
1998.
APS Manuscript Number F329-6.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 19 February 1998