Chemical sterilization in the male part I: rats

Adult male rats were injected intratesticularly with 3 mg and 6 mg zinc tannate (Kastrin) into each testis. Light microscopy and electron microscopy revealed that Kastrin is an effective irreversible chemical sterilant. Histological sections of testis indicated complete destruction of seminiferous tubules. Progeny testing of treated rats during a one-year period produced no pregnancy. No epididymitis or testicular teratoma were observed. Blood testosterone level of rats treated with 3 mg zinc tannate did not change significantly; however, in rats treated with 6 mg zinc tannate, blood testosterone level decreased significantly by 79% (p less than 0.0001).