Old Rats Are More Susceptible to Induction of Benign Prostatic Hyperplasia (BPH) at Comparative to Young Mature.

Aims: The aim of the experiments was to find out the factors on which age-related sensitivity to the occurrence of BPH depends.

Methods: 45 Male Wistar rats aged 3 and 24 months were used. In each age group, there were intact rats and animals with induced BPH (by surgical castration + testosterone injections, 25 mg/kg x 7). On the 36th day of the experiment, blood was taken from rats to determine serum testosterone, cholesterol, triglycerides and glucose; then, the animals were autopsied, their prostates were weighed, and their morphology was studied.

Results: Young mature intact rats had much higher testosterone levels (6.2±0.93 nmol/l) than old intact (3.8±0.55 nmol/l), while the ratio of prostate weight was inverse. The weight of the prostate and prostatic index in old rats with induced BPH was significantly higher not only in comparison with the old intact rats but also with young animals after BPH induction. Morphologically, the inflammatory foci were determined not only in the prostates of old rats, which induced BPH, but also in intact animals. Besides, in old intact rats, the foci of prostate hyperplasia were often noted.

Conclusion: Our experimental model indicates the important role of non-bacterial prostatitis in the pathogenesis of BPH. No metabolic disorders in BPH induction were revealed. The sensitivity of the prostate of old rats to BPH development is increasing despite the low concentrations of testosterone in the body. Age sensitivity to BPH is probably determined by a higher expression of androgen receptors in old animals.