CHICK KIDNEY ADENYLATE CYCLASE: SENSITIVITY TO PARATHYROID HORMONE AND SYNTHETIC HUMAN AND BOVINE PEPTIDES

Abstract

SUMMARY Adenylate cyclase activity of crude plasma membranes from chick kidney was stimulated by low doses of parathyroid hormone (PTH). Sensitivity to PTH was ten to twenty times greater than that of a similar preparation from rat kidney cortex. Synthetic peptides consisting of the NH2-terminal 34 amino acids of bovine PTH (BPTH) and of human PTH (HPTH) were assayed, as were several analogues of these peptides. Bovine PTH (1–34) and HPTH (1–34) were equivalent in their action on chick kidney but the human peptide had only 20% of the activity of the bovine peptide on rat kidney cortex adenylate cyclase. Bovine proPTH ( −6→ + 34) and (Tyr1)-BPTH (1–34) had less activity than BPTH (1–34). Bovine PTH (2–34) inhibited the response to BPTH (1–34). Neither salmon calcitonin nor vasopressin stimulated adenylate cyclase activity.