Abstract
Hexestrol dicaprylate (H8), a long-acting estrogen, was used in an attempt to induce temporary sterilization of adult male dogs. Each dog received a single intramuscular injection of H8 in oil. The doses were ranged from 0.1 to 2.0 mg/kg body weight. The morphological and histological changes in the testis, and androgen content of the testis were examined after H8 injection.
In cases of 0.5 to 2.0 mg/kg dose levels, spermatozoa in each seminiferous tubule disappeared within 30 days, and this seemed to continue over 150 days. In a dog treated with 0.5 mg/kg, sperma-tozoa were not found in the testis on day 180, but were found on day 240. Testosterone and andros-tenedione were assayed in H8-treated and non-treated dog's testicles by GLC. The content of both androgens decreased markedly within 48 hours after injection with a dose of 2.0 mg/kg of H8, and further decreased to undetectable amounts in the 72 hours samples. Up to 60 days after H8 injection, both androgens were in the undetectable level of our assay system.
This type of estrogen may probably be used for temporary sterilization of male dogs for about 6 month at the 0.5mg/kg dose level.
