Procarbazine has been implicated as a cause of infertility. Regionaliz
ation of drug delivery is a potential method to avoid this problem. We
investigated the protective effect of testicular circulatory isolatio
n (TCI) on gonadal toxicity during procarbazine administration in the
Sprague-Dawley rat. Four groups (n = 10/group) were used. Animals in g
roup 1 received no treatment. Rats in groups 2 and 3 were anaesthetize
d and received TCI of the left testis by clamping of the spermatic cor
d and gubernaculum immediately before a bolus of intravenous procarbaz
ine (400 mg kg-1). The clamping was maintained for 15 min after procar
bazine administration in group 2 and for 45 min in group 3. Rats in gr
oup 4 received sham surgery immediately before procarbazine administra
tion. On day 70, all rats were killed and necropsied. Testicular toxic
ity was evaluated qualitatively by histology and quantitatively by mea
surements of testicular weight, sperm head count, repopulation index,
and epididymal index. The results indicated that 15 min of TCI did not
mitigate testicular toxicity; 45 min of TCI provided moderate protect
ion against procarbazine-induced testicular toxicity.