AJP - Endocrinology and Metabolism, Vol 267, Issue 6 E828-E836, Copyright © 1994 by American Physiological Society
Ontogeny of the two angiotensin II type 1 receptor subtypes in rats
S. Shanmugam, P. Corvol and J. M. Gasc
Laboratoire de Medecine Experimentale, Institut National de la Sante et de la Recherche Medicale Unite 36-College de France, Paris.
The two subtypes (AT1A and AT1B) of the type 1 (AT1) angiotensin II
receptor mRNA were localized by in situ hybridization in rat fetal tissues
from day 11 to 19 of gestation and in the young rat from day 0 to 10
postpartum, by use of 35S-labeled cRNA probes. Both subtype mRNAs were
present in the kidney and in the adrenal gland. Organs such as liver, lung,
heart, and undifferentiated mesenchymes expressed only AT1A mRNA. In
contrast to the adult, only AT1A subtype was expressed during fetal and
postnatal periods in the pituitary gland. Large blood vessels (e.g., aorta
and cerebral arteries) expressed exclusively AT1A mRNA during fetal stages.
The expression of each subtype appears to be differentially regulated, in a
tissue- and age-specific way. This spatotemporal regulation of AT1A and
AT1B expression suggests that angiotensin II could act as a differentiation
factor during organogenesis in addition to its classical role as a
regulator of the cardiovascular system.
