Calcium metabolism in bullfrog tadpoles (Rana catesbeiana).
Non-feeding bullfrog (Rana catesbeiana) tadpoles can maintain their body Ca concentration in artificial pond waters containing a range of Ca concentrations. The rate of uptake of 45Ca increases when the tadpoles are pre-adapted to a low-Ca pond water and declines when they are pre-adapted to high Ca. Measurement of drinking rate shows that drinking could account for only 5% of the influx. From in vitro experiments, it is estimated that about 70% of the influx occurs accoss the gills, and about 25% through the skin. Calcitonin decreases accumulation of 45Ca while 1,25-(OH)2 vitamin D3 increases it; parathyroid hormone was without effect. Efflux of 45Ca was unchanged by calcitonin or parathyroid hormone.
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D007408:Intestinal Absorption; D007814:Larva; D011892:Rana catesbeiana / Q000254:growth & development / Q000378:metabolism*; D012867:Skin / Q000378:metabolism
D002118:Calcium