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

We used quantitative autoradiography to investigate distribution of angiotensin II (ANG II) receptor subtypes during development of the kidney in the rat. In fetal, newborn, and 3-day-old rats, immature glomeruli in the form of comma and S-shaped bodies, located in the nephrogenic zone of the renal cortex, expressed only the angiotensin AT2 receptor subtype. Conversely, the juxtamedullary glomeruli, in more advanced developmental stages, expressed only the AT1 subtype. Similarly, maturing and fully developed glomeruli, present in l-, 2-, and 8-wk-old rats, expressed only AT1 receptors. In the kidney medulla, there was a similar change in ANG II receptor subtype expression, with the AT2 subtype expressed earlier and the AT1 subtype later during development. Our results demonstrate a selective expression of ANG II receptor subtypes during kidney development. We have found glomerular and medullary AT1 receptors only at developmental stages when kidney function has matured. Conversely, AT2 receptors are expressed only in immature structures, suggesting that they may have a role during kidney organogenesis.