Inhibition of bovine parathyroid hormone-(1-34) on calimycin-induced spontaneous contraction of rat vas deferens
Abstract
The calcium ionophore calimycin(A-23187, CM)induced spontaneous contractions of the isolated rat vas deferens in dose-related manner closely dependent on calcium concentration in Krebs-bicarbonate solution.The effect of CM(10,50 microM) on this preparation was inhibited by bPTH-(1-34)(0.48, 1.44 nM) and phentolamine(0.1 mM).Phentolamine(10 microM) inhibited the norepinephrine-indcued contraction but bPTH-(1-34) did not. The finding suggest that the inhibitory effect of bPTH-(1-34) on the spontaneous contractions induced by CM may be the result of ioterference with the availability of calcium in releasing endogenous norepinephrine.
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