Dynamic study of nervous control on prostatic contraction and fluid excretion in the dog.

The effect of the section or stimulation of various nerves on prostatic contraction and fluid excretion was investigated dynamically in the dog using an apparatus devised in our laboratory. Prostatic contraction could be classified into two types from the pattern of the contracting wave. One was a prominent tonic contraction, designated as H-type contraction, observed typically after hypogastric nerve stimulation and followed always by prostatic fluid excretion. The other was a weak clonic contraction, designated as P-type contraction, occurring typically after pelvic nerve stimulation and accompanied by no fluid excretion. The periodical contraction of these two types was noticed even at rest. The H-type contraction was associated with fluid excretion with a mean rate of 0.3 ml./hr. The denervation both of the hypogastric and pelvic nerves showed no distinct influence on contraction and excretion in the resting condition. The pudendal nerve was demonstrated to have no significant effect on prostatic contraction and fluid excretion. From these results, it was considered that dynamic fluid excretion followed by prostatic contraction was regulated chiefly by sympathetic fibers from the hypogastric nerve and the physiological role of parasympathetic fibers from the pelvic nerve was something other than fluid excretion.