NONSPECIFIC DENERVATION SUPERSENSITIVITY IN RAT VAS DEFERENS IN-VITRO

A new method for the chronic denervation of the rat vas deferens was developed. The time course of norepinephrine content was investigated both chemically and histochemically and histochemically and correlated with the development supersensitivity of the vas denervated by this method to some stimulants in vitro. The content decreased rapidly and finally reached 1.7% of the initial level 4 days after the denervation. The disappearance of fluorescence observed in the control vas paralleled the fall in norepinephrine content determined chemically. Specific supersensitivity to norepinephrine appeared quite rapidly during the 2 days following denervation and attained a maximum within 4 days. The dose-response curve to norepinephrine was shifted to the left by a factor of about 50, and the maximum response was augmented about 3 fold. These two effects of denervation on the dose-response curve were assumed to result from pre- and postsynaptic mechanisms, respectively. Supersensitivity to acetylcholine, angiotensin, K+ and Ba++, which could be regarded as nonspecific and postsynaptic also developed rapidly. Their respective supersensitivities developed in parallel with the decrease in sympathetic transmitters in the vas deferens. The mechanism of the postsynaptic nonspecific supersensitivity after denervation in the rat vas deferens is discussed in relation to nonspecific supersensitivity caused by cocaine in the vas on which we reported previously. © 1969.