Effects of delivering different amounts of dihydrotestosterone by ceramic implants on the reproductive system of male rats.

Administration of drugs or hormones to patients, orally or by injections, results in a pulsatile delivery of the drug. The purpose of this study was to determine whether dihydrotestosterone (DHT), delivered in a sustained manner by ALCAP ceramic capsules, can regulate fertility in male rats. Sixty rats were distributed equally into 4 groups. Each of the 15 capsules (1.60 +/- 0.01 gm/cm3) in groups I, II and III was loaded with 30, 60, and 90 mg DHT, respectively and implanted in rats. Rats in group IV served as controls and were implanted with empty capsules. Five rats from each group were euthanized at the end of 1, 2, and 3 months. The data obtained showed that the weights of vital organs of rats in all groups did not differ significantly. At the end of 3 months, accessory reproductive organs (ARO) in group I and group II rats showed significantly lower sperm counts, but maintained the weights of ARO. Group III rats did not show a significant decrease in the sperm counts or weights of ARO in comparison to values obtained for control rats. The data obtained suggest that DHT, delivered in appropriate amounts by ceramic capsules, can be used to regulate fertility in mammals.