Comparison of K+-p-nitrophenyl phosphatase activity in the urinary bladderof the frog Rana esculenta during hibernation and active life

We have studied effects of hibernation on the frog urinary bladder, an orga n involved in water and ion transepithelial transport and taking part in os moregulation. We have demonstrated K+-p-nitrophenyl phosphatase activity (a n enzyme involved in ion and water transport) both in active and hibernatin g frogs, Most of the reaction product deposition was found on basolateral m embranes of granular cells of the urinary bladder epithelium during all sea sons. Therefore, it seems likely that this organ, unlike organs studied pre viously (skin, kidney and lung), maintains its function in the osmoregulato ry process during hibernation.