PROTECTION OF SPERMATOGENESIS AGAINST CYTOTOXIC EFFECTS OF 2 CHEMOTHERAPEUTIC DRUGS BY TEMPORARY TESTICULAR BLOOD-FLOW INTERRUPTION IN THE RAM

Temporary interruption of the testicular blood flow for 1 h after inje ction of cytostatic drugs has a protective effect on spermatogenesis. This was shown in experiments in which spermatogenesis was evaluated a t four weeks after a single intravenous injection of Adriblastina(R) ( ADR; doxorubicine hydrochloride) or Mitomycin-C-kyowa(R) (MIT). Interr uption of the blood flow was performed by inflation of an occluder imp lanted around the testicular artery. The animals were killed and histo logical sections prepared 4 weeks after treatment. In all drug-treated animals spermatids were near absence and spermatocytes were decreased in number. Therefore, even after occlusion of the blood flow, the dru g doses were high enough to kill not only large numbers of differentia ting spermatogonia but also stem cells. The response of the stem cells to the treatments was evaluated by counting the numbers of A spermato gonia per 100 Sertoli cells in the different groups. Normal numbers of these cells were found after both MIT and ADR, indicating that the st em cell population had responded to the initial cell loss by extra pro liferation. However significantly higher numbers of A spermatogonia we re found in the drug-treated animals in which the testicular blood flo w was interrupted for 1 h. This indicates that occlusion of the blood flow to the testis for 1 h results in a faster recovery of spermatogen esis than after drug treatment alone.