Chick Kidney Adenylate Cyclase: Sensitivity to Parathyroid Hormone and Synthetic Human and Bovine Peptides

Abstract

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\p=n-\34) and HPTH (1\p=n-\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 ( \m=-\6\ar=r\+ 34) and (Tyr1)\ x=req-\ BPTH (1\p=n-\34) had less activity than BPTH (1\p=n-\34). Bovine PTH (2\p=n-\34) inhibited the response to BPTH (1\p=n-\34). Neither salmon calcitonin nor vasopressin stimulated adenylate cyclase activity.

Enzymatic modification of bovine and ovine parathyrin receptor

“…The glycoprotein nature of bovine receptor and the critical importance of phospholipids for bPTH binding are evident. This result may possibly be relevant in the interpretation of species differences described for the interaction of bPTH with receptor preparations from different species [12][13][14].…”

Studies In Vivo on the Effects of Parathyroid Hormone upon Kidney Cyclic Adenosine 3',5'-Monophosphate Content using Rapid Tissue Fixation by Microwave Irradiation

“…It is possible that arginine vasotocin and calcitonin, which activates renal adenylate cyclase in mammals (Marx, Woodward andAurbach 1972, Kurokawa, Nagata, Sasaki andNakene 1974) affect kidney cyc1ic AMP content more slowly than did PTH. However, calcitonin does not activate adenylate cyc1ase in chick kidney plasma membranes (Martin et al 1974). Doses of prostagIandin EI higher than 100 ng produced flaccid paralysis in these young chicks .…”

“…It was of considerable interest, therefore, that the synthetic fragment PBTH (2-34) was active in increasing kidney cyc1ic AMP content in the intact animal. This fragment inhibits the action of PTH on chick kidney plasma membrane adenylate cyc1ase, indicating that it is probably capable of combining with the PTH receptor (Martin et al 1974). However the fragment does not activate membrane adenylate cyc1ase in vitra unless the guanosine 5'-triphosphate (GTP) analogue 5'-guanylylimidodiphosphate is present (Hunt et al 1976).…”

Hormone metabolism and response of adenylate cyclase to parathyroid hormone in kidney

“…It is relevant to note from Fig. la and b that synthetic human PTH (1-34), which has only 20% of the potency of bovine PTH (1-34) in the rat kidney adenylate cyclase assay (Martin et al, 1974), was nevertheless slightly less susceptible than the bovine peptide to inactivation by rat kidney membranes. The conclusion from these experiments that in uitro inactivation of PTH is irrelevant to activation by the hormone does differ from the findings of Desbuquois & Cuatrecasas (1972) for glucagon.…”