Effect of Finasteride or Castration on Rat Ventral Prostate

Lim, Joung Hwan; Oh, Bong Ryoul; Ryu, Soo Bang

Abstract

PURPOSE: We compared the extent of prostatic involution after treatment with finasteride, a potent 5alpha-reductase inhibitor, with those caused by castration.
MATERIALS AND METHODS
Rats were divided into two groups: finasteride-treated and castrated ones. Finasteride-treated rats were given 1mg/kg a day orally. The rats were sacrificed immediately, and on days 1, 3, 5, 7, 10, 14 and 21 after treatment. The prostate was immediately removed, weighed and either prepared for histological examination detecting apoptotic bodies by hematoxylin and rosin staining or frozen in liquid nitrogen for the determination of intraprostatic DHT concentration and DNA content, for detection of 180-bp DNA ladder by agarose gel electrophoresis.
RESULTS
Either finasteride or castration decreased prostate weight and DNA content, which the degree of decrease was more pronounced in castrated group than in finasteride-treated group. Both finasteride and castration caused a decrease in intraprostatic DHT concentration, which these processes occurred to a more rapid and greater extent in finasteride-treated group. By 3 days of finasteride treatment, the intraprostatic DHT concentration decreased to a greater extent with no further significant change thereafter, while castration decreased gradually in intraprostatic DHT concentration up to day 10, with no further significant decrease thereafter. In the pattern of cell loss determined by hematoxylin and eosin staining, apoptotlc bodies were observed typically in castration group but not in finasteride-treated group. In agarose gel electrophoresis, 180-bp DNA ladder was found in finasteride-treated group through experimental days but in castrated after 3 days of experiment this ladder was not found.
CONCLUSIONS
We concluded that castration caused a more profound involution of rat ventral prostate than finasteride. But the extent of prostatic involution was not correlated with intraprostatic DHT concentration. Although we could not found the apoptotic body in finasteride-treated group, the 180-bp DNA ladder suggesting apoptosis was detected.