SPECIFIC CHANGES IN THE CHOLINERGIC SYSTEM IN GUINEA-PIG VAS-DEFERENS AFTER DENERVATION

  • 1 January 1980
    • journal article
    • research article
    • Vol. 215  (3) , 716-722
Abstract
A small rapid phase (1st phase) was distinguished from a concomitant phase (2nd phase) in contraction of guinea-pig vas deferens. The vas deferens 4 days after denervation exhibited supersensitivity to stimulants. The supersensitivity in the 2nd phase of contraction was nonspecific. In the 1st phase supersensitivity was specific to muscarinic cholinergic agonists. The increase in sensitivity resulted in a shift of the dose-response curve to lower concentrations without significant change in the maximal response. Muscarinic cholinergic receptors in the vas deferens, determined by measuring binding of [3H]quinuclidinyl benzilate, changed after denervation. The maximal binding sites increased from 115-165 f[femto]mol/mg of protein with no significant change in the Kd. The affinity of the receptor for agonist did not change significantly. [3H]WB4101 [[3H]-2-[[2''-6''-dimethoxy]phenoxyethylamino]methyl benzodioxan] binding indicated no significant change in .alpha.-adrenergic receptors after denervation. Specific supersensitivity of the cholinergic mechanism mediated by muscarinic acetylcholine receptors apparently occurred after denervation of guinea-pig vas deferens. This increased sensitivity is discussed in relation to the amount of receptor.

This publication has 0 references indexed in Scilit: