The effects of chlormadinone acetate (CMA), antiandrogen, on the pituitary, testis, prostate and adrenal gland of the dog with spontaneous benign prostatic hyperplasia

Abstract

The effect of chlormadinone acetate (CMA), a synthetic steroidal antiandrogen, 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 and 3 received CMA 0.03 and 0.1 mg/kg/day, p.o., respectively, for 6 months. In group 1, glandular hyperplasia of the prostate was clearly detected. The glandular epithelial cells showed uniformly intense nuclear staining for androgen receptor (AR). AR was also localized in the nuclei of the fibro-muscular stromal cells. In groups 2 and 3, CMA produced marked atrophy of the glandular epithelium. The interacinar fibro-muscular stroma was prominent. The nuclear staining for AR in both epithelial and stromal cells was remarkably decreased. In addition, a histopathological study showed that CMA medication for 6 months exerted no effect on the testes and adrenal glands or on immunoreactive positive cells to LH- and ACTH-antibody (pituitary LH- and ACTH-cells). Therefore, it is concluded that CMA (0.03 and 0.1 mg/kg) causes regression of spontaneous canine BPH without any histopathological effects on the testes, adrenal glands or pituitary LH- and ACTH-cells.