Early rise in cyclic GMP after 1,25-dihydroxycholecalciferol administration in the chick intestinal mucosa

cGMP and cAMP levels were measured in the duodenal mucosa of 12-day-old chicks that had been raised from hatching in vitamin D-depleting conditions and at the time of use were moderately hypocalcemic. After administration of a dose (250 ng) of 1,25-dihydroxycholecalciferol, the cGMP levels increased about twofold in 2–3 hr and returned to control levels between 4 and 6 hr. Our data suggest that 1,25-dihydroxycholecalciferol behaves like other steroid hormones which induce an early rise in cGMP in their respective target tissues.