Hemodynamic effects of bPTH(1-34) and its analogue Nle8,18Tyr34bPTH(3-34) amide.

Abstract

We examined the vascular effects of bovine PTH(1-34) and of an analogue, Nle8,18Tyr34bPTH(3-34) amide, which inhibits adenylate cyclase activation by bPTH(1-34) in a number of in vitro systems. In the conscious dog. bPTH(1-34) injection produced dose-dependent hypotension associated with increased heart rate and cardiac output. The (3-34) analogue had no hypotensive effect in doses up to 6.0 micrograms/kg (1.5 nM/kg). In vitro studies revealed that bPTH(1-34) relaxed pitressin-contracted helical strips from the rat caudal artery. The (3-34) analogue displayed a weak, but definite inhibitory effect against the vasorelaxant effects of bPTH(1-34) with a pA2 of 5.5. The results further characterize the previously established hypotensive and vasorelaxant actions of bPTH(1-34), and suggest that the (3-34) analogue, which inhibits adenylate cyclase generation by bPTH(1-34) in nonvascular tissues, antagonizes the vasorelaxant effects of bPTH(1-34) as well. The results provide suggestive evidence that the vasorelaxant effects of bPTH(1-34) may be mediated by adenylate cyclase.

• Authors: J T Daugirdas, R R Al-Kudsi, T S Ing, M C Yang, D J Leehey, P K Pang
• Journal: Mineral and electrolyte metabolism (Miner Electrolyte Metab) Vol. 13 Issue 1 Pg. 33-7 ( 1987) ISSN: 0378-0392 [Print] Switzerland
• PMID: 3587182 (Publication Type: Journal Article)

Chemical References

• Parathyroid Hormone
• Peptide Fragments
• parathyroid hormone (1-34), bovine
• parathyroid hormone (3-34) amide, Nle(8,18)-Nle(34)-

Topics

• Animals
• Arteries (drug effects)
• Blood Pressure (drug effects)
• Dogs
• Female
• Hemodynamics (drug effects)
• In Vitro Techniques
• Male
• Parathyroid Hormone (antagonists & inhibitors, pharmacology)
• Peptide Fragments (antagonists & inhibitors, pharmacology)
• Vasodilation (drug effects)