Synthetic tumor-derived human hypercalcemic factor exhibits parathyroid hormone-like vasorelaxation in renal arteries

• Published in: Biochemical and biophysical research communications Vol. 149; no. 1; pp. 227 - 232
• Main Authors: Winquist, Raymond J., Baskin, Elizabeth P., Vlasuk, George P.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 30.11.1987; Elsevier
• Subjects: Animals; Applied sciences; Colforsin - pharmacology; Cyclic AMP - metabolism; Exact sciences and technology; Humans; Male; Methoxamine - pharmacology; Muscle Contraction - drug effects; Muscle Relaxation - drug effects; Neoplasm Proteins - pharmacology; Other techniques and industries; Parathyroid Hormone - pharmacology; Parathyroid Hormone-Related Protein; Peptide Fragments - pharmacology; Proteins; Rabbits; Renal Artery - drug effects; Renal Artery - physiology; hPTH; hHF
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/0006-291X(87)91628-7

Synthetic human tumor hypercalcemic factor (1–34, hHF) was compared with parathyroid hormone (human sequence, 1–34; hPTH) for vasorelaxant activity in isolated rabbit renal artery segments. The hHF exhibited a potent (IC50 = 1.3×10−9M) and profound (98%) relaxation which was significantly greater in magnitude than that obtained for hPTH (IC50 = 4.5×10−9M; maximal relaxation = 78%). The relaxations to both peptides were concentration-dependent and not associated with changes in cyclic AMP levels. These results demonstrate a parathyroid hormone-like response, independent of adenylate cyclase activation, in isolated renal arteries. Renal vasodilation may be important for the effects on renal function shared by these two peptides.