射精の研究

第9報 精管内における精子の移送のメカニズムについて

抄録

In this paper an attempt was made to elucidate the mechanism of the transportation of spermatozoa in the vas deferens in male mongrel dogs.
Methods: Intraluminal pressure of the vas deferens was measured in vivo by inserting one or two polyethylene tubes to the lumen of the vas deferens and the number of the spermatozoa transported to the end of the vas deferens or to the posterior urethra was measured. The autonomic drugs were administered intra-aortically.
Results are as follows:
1. Autonomic contraction of the vas deferens. Measurement of the intraluminal pressure clarified that the vas deferens repeated autonomic contraction. This contraction was not so-called peristalsis but the entire portion of the vas deferens contracted simultaneously. When autonomic contraction was repeating, the posterior urethra was washed with physiologic saline every 15 minutes. One or two spermatozoa were present in every 400x field of the sediment of the saline. Then, the lumen of the vas deferens was irrigated with 2.5% and 10% formalin for 10 minutes to inhibit the cilial movement of the epithelium and the movement of the spermatozoa. Even after the irrigation the spermatozoa were present in the posterior urethra. These results indicate that the spermatozoa in the cauda epididymidis and the proximal portion of the vas deferens are continously transported by the autonomic contraction and that transportation of spermatozoa is not confined to ejaculation.
2. Stimulation of the hypogastric nerve. Stimulation of the hypogastric nerves caused a rise of the pressure at the proximal portion of the vas deferens. The rise of the pressure began 5-10 seconds after the commencement of the stimulation. The pressure near the peripheral end of the vas deferens began to rise 5-10 seconds later than the rise of the pressure of the proximal portion. Then, the testis and epididymis was separated with a ligature between them. Hypogastric nerve stimulation caused a rise of the intra-luminal pressure of the vas deferens like before the ligation. After the ligature of the transitional portion between the epididymis and vas deferens the intraluminal pressure of the vas deferens rose by hypogastric nerve stimulation. The vas deferens was separated into two portions, i. e., the proximal and distal portions with another ligature at its mid-portion in addition to the ligature between the epididymis and vas deferens. The stimulation of the hypogastric nerves caused a rise in the pressure of the proximal portion, whereas a slight fall followed by a slight rise was observed in the pressure of the distal portion. Actually, hypogastric nerve stimulation transported a considerable number of spermatozoa to the peripheral end of the vas deferens. These results indicate that spermatozoa are transported in the following manner: During ejaculation the stimuli through the hypogastric nerves elevated the pressure in the ductus epididymidis and the proximal portion of the vas deferens. This elevation pressed the spermatozoa from the epididymis and proximal portion of the vas deferens toward the posterior urethra.
3. The effect of the autonomic drugs on the transportation of spermatozoa by hypogastric nerve stimulation. Phentolamine in a dose of 1-10mg suppressed the rise of the intraluminal pressure of the vas deferens induced by hypogastric nerve stimulation and blocked the transportation of the spermatozoa in the vas deferens. Almost no changes were observed in the rise of the intraluminal pressure of the vas deferens and in the transportation of the spermatozoa after the administration of propranolol (1-10mg), atropine (1-10μg) or hexamethonium (100-500μg). These results indicate that an α-adrenergic mechanism is mainly involved in the transport of spermatozoa in the vas deferens.
4. Effects of sectioning of the peripheral nerves and the administration of autonomic drugs on the autonomic contration of the vas deferens. Sectioning of the hypogastric ner