ADRENERGIC AND CHOLINERGIC MECHANISMS IN THE HYPOGASTRIC NERVE-SEMINAL VESICLE PREPARATION OF THE GUINEA-PIG

Effects of autonomic agents on the responses produced by hypogastric nerve and transmural stimulation of the hypogastric nerve-seminal vesicle preparation of the guinea-pig were examined. Hexamethonium and nicotine blocked the responses to hypogastric stimulation leaving the contractions due to transmural stimulation . TTX and xylocaine blocked both responses. Spontaneous contraction which was observed in 30% of the preparation was not abolished by TTX, hexamethonium, guanethidine and atropine. Acetylcholine, metacholine and noradrenaline elicited or potentiated the spontaneous activity.Adrenaline, noradrenaline, phenylephrine and nialamide enhanced the responses produced by the stimulation of hypogastric and transmural stimulation while guanethidine and phenoxybenzamine reduced the responses. Acetylcholine, metacholine, carbachol and cholinesterase inhibitors increased the responses. Atropine and bevonium inhibited the responses. Required pulse number in the transmural stimulation for producing the contraction was decreased in nialamide, metacholine, carbachol, physostigmine and neostigmine and increased in phenoxybenzamine, guanethidine and atropine.The possibility that adrenergic and cholinergic mechanisms operate independently of each other in the seminal vesicle preparation was discussed.