VENTRAL PROSTATE STRUCTURE AND SERUM TESTOSTERONE LEVELS IN RATS WITHDIFFERENT ANDROGEN STATUS AFTER CHRONIC TREATMENT WITH PROPRANOLOL

The effects of chronic, 15-day, administration of the beta-adrenergic antagonist propranolol (4 mg/kg/d; subcutaneously) on the ventral pros tate structure and serum testosterone concentrations were examined in rats with different androgen status, that is immature, adult testoster one-injected (1 mg/rat) and chemically castrated animals. Chemical cas tration was evoked by an intraperitoneal injection of ethane dimethane sulfonate (EDS) (75 mg/kg). A ventral prostate response was observed i n immature and in adult chemically castrated animals. Stereological an alysis, performed on paraffin sections of the gland, suggested that in immature rats a discharge of glandular secretion occurred. In additio n, in these animals alterations were found in the morphometric paramet ers of the ventral prostete blood vesels, their total volume being dec reased. In chemically castrated rats, administration of propranolol fr om the day of EDS application partially prevented the postcastrational atrophy of the ventral prostate. The changes in the ventral prostate both in immature and adult chemically castrated rats were not accompan ied by alterations in blood testosterone level. These results show tha t chronic treatment with propranolol may affect both contractile and s ecretory elements of the rat ventral prostate depending on the androge n status of the animals and, accordingly, on the site of propranolol-a ction.