Prostatic contraction and fluid excretion in the dog were recorded electrically after section or stimulation of various nerves innervating the prostate, using a newly developed apparatus. The results obtained were as follows:
1) The prostatic contraction could be classified into H-type and P-type from the pattern of contracting wave. The former was observed typically after the hypogastric nerve stimulation and followed by the prostatic fluid excretion, while the latter occurred typically after the pelvic nerve stimulation and resulted in no excretion.
2) The periodical contraction of both two types was noticed even in resting condition. The Htype contraction was associated with the fluid excretion with a mean rate of 0.3ml/hour.
3) The innervation showed no direct influence on the contraction and secretion in resting condition.
4) The H-type contraction was a severe tonic contraction towards one direction for the purpose of the fluid excretion. A close relationship was observed between the degree of the contraction and the fluid excretion rate. The pathway of nerves controlling this type of contraction was as follows: II-IV lumbar spinal cord→connected lumbar nerves→connected ganglions of sympathetic trunk→II-IV inferior splanchnic nerves→inferior measenteric plexus→hypogastric nerve.
5) The P-type contraction was a weak clonic contraction. Its effect should be something other than the fluid excretion. The pathway of nerves controlling this type of contraction was as follows: II-III sacral spinal cord→connected sacral nerves→pelvic nerve. On the other hand, it was assumed that lower lumbar spinal cord receives centripetal stimuli from the ventral rami of lower lumbar nerves and mediates it to the above mentioned pathway originated in sacral spinal cord.
6) It was supposed that pudendal nerve has no influence on the prostatic contraction and excretion.