Postnatal development of the kidney juxtaglomerular apparatus in rats

Abstract

The development of the juxtaglomerular (JG) apparatus in the rat kidney was investigated at different times of postnatal life (1, 2, 3, 5, 7, 10, 15, 30 and 60 days). On the 1st day after birth, secretory granules were found in JG cells in preglomerular arterioles of juxtamedular nephrons and in interlobular arteries. JG indices are high at this stage and decrease until the 5th day, then gradually rise until the 60th day. The possible reasons for such findings are discussed. Macula densa cells start to differ as early as the 1st day after birth. They are very distinct already at 2 days and they reach typical organization by the 15th day. Extraglomerular mesangial cells are few in early postnatal life. Their number increases later on. The parallelism between nephrogenesis and development is discussed.

Characterization and localization of leptin receptors in the rat kidney

“…5). In contrast to a number of other organs, the kidney is not morphologically and functionnally fully differentiated until about day 60, referred to the adult period [21,22]. Although the autoradiographic techniques used did not allow localization at the cellular level, this study provided further evidence that […”

“…Male Sprague-Dawley rats at various ages (8,21,30, 60 and 84 days old) were decapitated and the kidneys were rapidly removed and frozen in isopentane at -40°C. Serial sections (16 urn) were cut in a cryostat microtome and thaw-mounted into chrom-alum gelatincoated glass slides (gelatin 1%, chrom-alum 0.05%).…”