Abstract
The effect of a synthetic steroidal antiandrogen, chlormadinone acetate (CMA), on spontaneous benign prostatic hyperplasia (BPH) in dogs was investigated. Male beagle dogs (5-8 years old) were divided into four experimental groups. Group 1 consisted of untreated controls. Groups 2 to 4 received CMA 0.03, 0.1, and 0.3 mg/kg/day, p.o., respectively, for 6 months. In group 1, glandular hyperplasia of the prostate was clearly detected. In groups 2 to 4, CMA produced marked atrophy of the glandular epithelium. In addition, a histopathological study showed that CMA medication for 6 months exerted no effect on the testes except group 4 or on immunoreactive positive cells to LH antibody (pituitary LH cells). Therefore, it is suggested that CMA (0.03 and 0.1 mg/kg) causes regression of spontaneous canine BPH without any histopathological effects on the testes or pituitary LH cells. However, atrophy of seminiferous tubules in testes was found in CMA 0.3 mg/kg/day-treated animals, due apparently to a direct and/or indirect effect on the testes. It is suggested that a marginal antigonadotrophic effect can not be excluded.
