Hormonal control of the renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol.
Isolated renal tubules from vitamin D-deficient chicks catalyse the in vitro conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol. This conversion is stimulated by 5 x 10(-10) M bovine parathyroid hormone, or by 10(-6) M cyclic AMP. It is inhibited by 10(-9) M porcine calcitonin. It is concluded that these hormonal controls of the synthesis of the renal hormone 1,25-dihydroxycholecalciferol are of particular physiological significance in coordinating the activities of the various organs involved in extracellular calcium homeostasis.
D000818:Animals; D002116:Calcitonin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002645:Chickens; D046508:Culture Techniques; D000242:Cyclic AMP / Q000494:pharmacology; D006887:Hydroxycholecalciferols / Q000032:analysis / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism*; D008722:Methods; D010281:Parathyroid Hormone / Q000494:pharmacology; D013268:Stimulation, Chemical; D014808:Vitamin D Deficiency / Q000378:metabolism
D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D002116:Calcitonin; D000242:Cyclic AMP; D002118:Calcium