Effects of hypophysectomy on age-related changes in the rat kidney glomerulus: observations by scanning and...

The kidney glomeruli of 9-month-old intact, 23-month-old intact, and 23-month-old hypophysectomized female rats were examined by scanning and transmission electron microscopy. With increasing age, the glomeruli increased in diameter and more podocyte microvilli were found. Hypophysectomy (4 months before sacrifice) reduced these values to levels approaching values seen in the 9-month intact controls. Transmission electron microscopy revealed that increased numbers of podocytes and endothelial cells had cytoplasmic dense bodies with advancing age. Granular cytoplasmic material, seen in podocytes, did not alter in frequency with age. Hypophysectomy reduced the number of cells containing the dense bodies as well as the number of podocytes containing granular material. Basal laminar thickness, while increasing with age, was unaffected by hypophysectomy. The results show that hypophysectomy can return some structural age-related changes to values seen in younger subjects. The effects are similar in some respects to the effects of dietary restriction.