GLOMERULAR ANGIOTENSIN-II RECEPTOR SUBTYPES DURING DEVELOPMENT OF RAT-KIDNEY

We used quantitative autoradiography to investigate distribution of an giotensin II (ANG II) receptor subtypes during development of the kidn ey in the rat. In fetal, newborn, and 3-day-old rats, immature glomeru li in the form of comma and S-shaped bodies, located in the nephrogeni c zone of the renal cortex, expressed only the angiotensin AT2 recepto r subtype. Conversely, the juxtamedullary glomeruli, in more advanced developmental stages, expressed only the AT1 subtype. Similarly, matur ing and fully developed glomeruli, present in l-, 2-, and 8-wk-old rat s, expressed only AT1 receptors. In the kidney medulla, there was a si milar change in ANG II receptor subtype expression, with the AT2 subty pe expressed earlier and the AT1 subtype later during development. Our results demonstrate a selective expression of ANG II receptor subtype s during kidney development. We have found glomerular and medullary AT 1 receptors only at developmental stages when kidney function has matu red. Conversely, AT2 receptors are expressed only in immature structur es, suggesting that they may have a role during kidney organogenesis.