title: Seasonal variation in the active transporting ability and in the membrane ATPase activity of the frog intestinal epithelium.
abstract: The active sugar and amino acid transport in the small intestine of the American leopard frog (Rana pipiens) and a species of European frog (Rana esculenta) decreases during the winter months. Parallel with this the (Na+, K+)-stimulated ("pump") ATPase activity is markedly depressed. No seasonal changes are observed in the intestine of the tropical bullfrog (Rana catesbeiana). It is assumed that the low pump-ATPase activity is caused by the hibernation of the frogs living in moderate or subtropical areas and is connected to a biological clock. The decreased active transport of non-electrolytes appears to be a consequence of the change of the ATPase activity.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001001:Anura; D001683:Biological Clocks; D001693:Biological Transport, Active; D007413:Intestinal Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism*; D008757:Methylglucosides / Q000378:metabolism*; D008759:Methylglycosides / Q000378:metabolism*; D008861:Microsomes / Q000201:enzymology; D010649:Phenylalanine / Q000378:metabolism*; D011893:Rana esculenta; D011894:Rana pipiens; D012621:Seasons
chemical_list: D008757:Methylglucosides; D008759:Methylglycosides; D010649:Phenylalanine; D000251:Adenosine Triphosphatases