Ultrastructure of the renal corpuscle of Testudo graeca Chelonia. A comparison between hibernating and non-hibernating animals.

Abstract

The renal corpuscle of hibernating and nonhibernating Testudo graeca was studied by means of light and electron microscopy. Renal corpuscles are small and have a glomerular architecture similar to that found in other vertebrates with a limited glomerular filtration rate. In hibernating animals, unlike non-hibernating, some n~orphologicacl hanges took place. The cells of the renal corpuscle were densely packed, podocytes and parietal cells bhowed a marked cytoplasmic vacuolization, there was a highly developed capillary basement membrane and the endothelial and mesangial cells showed abundant dense granules. These morphological features apparently correspond to a vacuolar degeneration. They may also be the morphological basis of the decrease in the glomerular filtration rate observed during this period.