Endogenous Nitric Oxide is Not Involved in Acute Parathyroid Hormone-Induced Hypotension in Rat: Effect of Hypertension and Hypoparathyroid Status

Abstract

The present study investigated the acute hypotensive effed of parathyroid hormone (PTH) in anesthetized adult spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto rats. Furthermore, in order to determine the possible contribution of nitric oxide (NO), a mediator of endothelium-dependent vasorelaxation, hypotensive responses to PTH were obtained in the presence of N^G-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthesis. The hypotensive effect of PTH (expressed as % of baseline blood pressure) was similar for the two strains. In the presence of 1-NAME (18.5 µmol/kg), both strains demonstrated a similar hypotensive response to PTH, indicating that the hypotensive response to PTH is NO-independent.

Nitric Oxide - Parathyroid Hormone - Spontaneously Hypertensive Rats - Hypotension - N^G-Nitro-L-Arginine Methyl Ester