These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Specific H+/K(+)-ATPase inhibitors decreased contractile responses of isolated rat vas deferens.
    Author: Yenişehirli A, Onur R.
    Journal: Pharmacol Res; 2006 Dec; 54(6):397-405. PubMed ID: 16949299.
    Abstract:
    The effect of H(+)/K(+)-ATPase inhibitors on rat vas deferens contractility was investigated in vitro. Omeprazole (100-300microM), lansoprazole (100-300microM) and SCH 28080 (10-100microM) (2-methyl-8-(phenylmethoxy)-imidazo[1,2-a]pyridine-3-acetonitrile) decreased contractile responses of vas deferens to electrical field stimulation, high K(+) (80mM) and phenylephrine in a reversible, reproducible and concentration-dependent manner. The inhibitory potency of lansoprazole on vas deferens contractility was increased in relatively acidic solution (pH 6.9), suggesting that the site of action may be related to H(+)/K(+)-ATPase. However, lansoprazole-induced inhibition on contractility was unaltered in K(+) free solution, indicating that the mechanism of action is independent from H(+)/K(+)-ATPase. Reversible nature of omeprazole and lansoprazole-induced inhibition on contractility also suggests that the effects are not due to inhibition of H(+)/K(+)-ATPase, since both compounds are irreversible inhibitors of the enzyme. Presence of ouabain (5microM) did not decrease lansoprazole-induced inhibition on contractility but potentiated the inhibitory effect of lansoprazole, suggesting that lansoprazole-induced inhibition is not mediated by the inhibition of Na(+)/K(+)-ATPase. Calcium-induced contractions in high K(+)-Ca(2+) free medium were completely antagonized by lansoprazole, implying that lansoprazole inhibits Ca(2+) entry through voltage-gated channels. In conclusion, three H(+)/K(+)-ATPase inhibitors decreased contractile responses of rat vas deferens to various stimulants in vitro. They may act on a common mechanism, which plays a crucial role in regulating rat vas deferens contractility and this mechanism is probably involved in the regulation of intracellular Ca(2+).
    [Abstract] [Full Text] [Related] [New Search]