Testicular blood flow in peripubertal and older rats with unilateral experimental varicocele and investigation into the mechanism of the bilateral response to the unilateral lesion.

Testicular and reference organ blood flows and testicular temperatures were determined in peripubertal and mature rats with and without experimental left varicocele (ELV). Testicular blood flow and temperature were significantly increased bilaterally 30 days after surgery to induce unilateral varicocele, and this was the case in both the younger and older animals. It has not previously been known that the pathophysiological effects of ELV extended to the peripubertal testis. Previous experiments have demonstrated that the left testis is not necessary for the right testicular response to varicocele. In the present paper, animals were subjected to left orchiectomy simultaneously with the surgery to induce ELV. Thirty days later, the animals were divided into those with and those without the left spermatic vein varicosity. Testicular blood flow was determined in all these animals as well as in a separate group of control and experimental varicocele animals. The group of ELV animals with left spermatic varicosity demonstrated a significant increase in contralateral testicular blood flow while the ELV group without left spermatic varicosity did not. We speculate that left venous distention is involved in the mechanism for the contralateral response to unilateral varicocele.