Effects of Ganglionic Blocking Agents on Responses of Ductus Deferens Preparation of Guinea-Pig to Hypogastric Nerve Stimulation

Abstract

The sympathetic nature of the hypogastric innervation of the ductus deferens of guinea-pig has been concluded by Hukovic (1) from the results that the contractile response of the isolated ductus deferens to stimulation of the hypogastric nerve is en hanced by the addition of noradrenaline and is abolished by the previous reserpiniza tion of the animal. In the same line Boura et al. (2) (5) have demonstrated the enhancement of the response by the addition of eserine and various adrenolytics. The potentiating effect of the adrenolytics has been explained by the anticholinesterase activity of the drugs. The transmission failure of the sympathetic nerve impulse in the preparation by hemi cholinium has been shown by Chang and Rand (6) and Bentley (3). The inhibition of the contractile response by the ganglionic blocking agents has been shown by Sjostrand (7) and Bentley (3). Sjostrand (8) has proved that the chronic denervation of the ductus deferens does not affect the level of noradrenaline in the tissue. He has further indi cated that the cholinergic mechanism of impulse transmission in the preparation is responsible for the release of the endogenous noradrenaline.The assumption that the peripheral cholinergic mechanism is involved in the sym pathetic innervation of the ductus deferens of guinea-pig facilitated the current studies. METHODSSympathetically innervated ductus deferens preparation : Male guinea-pig, weighing 250 to 500 g, was killed by a blow on the head. The ductus deferens attached with hypo gastric nerve were prepared following the method devised by Hukovic (1).The preparation was tied by its proximal end to a hollow glass rod and by its distal end to a lever. It was set up in isolated organ-bath containing 50 ml of Kreb's solution at 31`C bubbled with 100% of oxygen. The contractile movement of the pre paration was recorded on the smoked drum.

RESISTANCE OF MECHANICAL AND ELECTRICAL RESPONSES TO HYPOGASTRIC NERVE STIMULATION TO Α-Blocking AGENTS IN GUINEA-PIG VAS DEFERENS

“…Many investigators have reported that the addition of noradrenaline into the bath augmented the contractile response of the vas deferens to hypogastric nerve stimulation (1,12,13). The intravenous injection of noradrenaline also augmented both the electrical and mecha nical responses to hypogastric nerve stimulation 10 minutes after the drug administration, but the degree of the augmentation of the responses was not so dramatic compared with that of the in vitro preparation (Fig.…”