Post‐natal Change in the Effect of Denervation on the Rat Vas Deferens

Abstract

SUMMARYThe vas deferens of 14-54 d old rats was denervated, isolated after 7 d, divided into prostatic and epididymal halves, and denervation supersensitivity to noradrenaline, acetylcholine, methacholine and tetramethylammonium (TMA) was examined. The supersensitivity to any of these agonists did not appear in rats younger than 21 d of age. Thereafter a leftward shift of the dose-response curve and an increase in the maximum contraction to noradrenaline were observed. The maximum contraction became progressively greater with development in the prostatic half but was approximately constant in the epididymal half. Supersensitivity to methacholine distinctly developed with age in the epididymal half. Only a subsensitivity to TMA was observed, suggesting that TMA acts on the nerve. The effect of denervation on the response to acetylcholine in the epididymal half resembled that to methacholine, and in the prostatic half resembled that to TMA. The developmental change in the effect of denervation on noradrenaline was discussed in relation to the full contractile ability of the vas halves, and that to cholinergic drugs was discussed in relation to nicotinic and muscarinic receptor population.

Parasympathetic denervation supersensitivity in the rat iris sphincter muscle : An in vitro study.

“…In another series of experi ments using BeCh, physostigmine and DFP in the present study, the maximum contraction after denervation was 132.6+5.7 mg for ACh and 144.0±4.5 mg for BeCh (n=10, P>0.05), respectively. Similar results have been obtained by Chiu-Wei et al (31) using developing rat vas deferens. These findings suggest the possibility that denervation enables these muscles to produce full con tractility in response to various agonists, resulting in a nonspecific supersensitivity.…”

Loss of nitrergic neurotransmission to mouse corpus cavernosum in the absence of neurturin is accompanied by increased response to acetylcholine

“…Supersensitivity to muscarinic receptor stimulation has been observed previously in a number of denervated smooth muscle preparations (Chiu‐Wei et al ., 1984; Hasegawa et al ., 1987; Braverman et al ., 1998). For example, this occurred in bladder detrusor and urethral smooth muscle of rats following bilateral pelvic ganglionectomy (Ekstrom & Malmberg, 1984a, 1984b); in this case, sensitivity to nitric oxide is unaffected (Persson et al ., 1998).…”