Hormonal responsiveness of adenylate cyclase activity in cartilage.

Adenylate cyclase activity was measured in a crude particulate fraction of hyaline cartilage obtained from the xiphoid process of the rat. Bovine parathyroid hormone (PTH) at concentrations as low as 1.3 x 10(-7)M and porcine calcitonin (CT) at concentrations as low as 2.3 x 10(-5)M significantly increased adenylate cyclase activity. Glucagon, prostaglandin E1 (PGE1) and E2 (PG2), and epinephrine at concentrations of 10(-5)M also increased activity, whereas, no increased activity was seen with the additions of somatotrophin (10 mug/ml), PGF1alpha, PGF2alpha, or T3 at 10(-5)M. The combination of doses of PTH and CT, which individually produced maximal responses, was not additive. These data provide evidence that cartilage in growing rats responds directly to PTH and CT.