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: Inhibition by ethanol of contractions of rat vas deferens: no evidence for selective blockade of P2X-purinoceptors.
    Author: Bültmann R, Szabo B, Starke K.
    Journal: Naunyn Schmiedebergs Arch Pharmacol; 1993 May; 347(5):527-33. PubMed ID: 8391654.
    Abstract:
    Some ligand-gated ion channels are important sites of action of ethanol. The aim of the study was to find out whether the P2X-purinoceptors mediating contraction of the rat isolated vas deferens also are selectively sensitive to ethanol. Contractions were elicited by ATP (1 mmol/l), alpha, beta-methylene ATP (0.3 mumol/l), noradrenaline (3 mumol/l), high K+ (20 mmol/l) or electrical (neural) stimulation by pairs of pulses 3 s apart. In electrical stimulation experiments, purinergic and adrenergic response components were isolated by prazosin and suramin, respectively. Concentration-effect curves were determined for ethanol and, for comparison, nifedipine. Tritium outflow from tissues preincubated with 3H-noradrenaline was also examined. Ethanol at relatively low concentrations reduced contractions elicited by high K+ (IC30 145 mmol/l), ATP (IC30 211 mmol/l) and alpha, beta-methylene ATP (IC30 215 mmol/l) as well the purinergic component of neurogenic twitches (IC30 110-126 mmol/l; a significant effect at 10-32 mmol/l) and the adrenergic component of twitch 2 of the twitch pairs (IC30 63 mmol/l). These contractions also were very sensitive to nifedipine. Higher concentrations of ethanol were needed to reduce contractions elicited by noradrenaline (IC30 365 mmol/l) and the adrenergic component of twitch 1 of the twitch pairs (IC30 382 mmol/l), contractions that also were less sensitive to nifedipine. Ethanol 1 mol/l abolished all contractions. In contrast, concentration-effect curves for the inhibition by nifedipine of contractions evoked by ATP, alpha,beta-methylene ATP and noradrenaline (rapid phase) levelled off at 60-70% inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)
    [Abstract] [Full Text] [Related] [New Search]