Effects of cortisol secreted via a 12-h infusion of adrenocorticotropic hormone on mineral homeostasis and bone metabolism in ovariectomized cows

Abstract To evaluate the effects of endogenously secreted cortisol on mineral homeostasis and bone metabolism in cows, 4 ovariectomized Holstein cows were infused for 12 h with either an adrenocorticotropic hormone (ACTH) solution (0.5 mg/2 L isotonic NaCl solution per cow) or isotonic NaCl solution in a 2 × 2 crossover design. ACTH infusion stimulated cortisol secretion and increased plasma cortisol concentrations for 18 h ( P P P P = 0.003, respectively). Similarly, the bone formation marker, bone-specific alkaline phosphatase, decreased continuously until 72 h after the ACTH infusion ( P