[Penetrability of amikacin into prostate tissues in rat models of chronic bacterial prostatitis].

OBJECTIVE

To establish the rat model of chronic bacterial prostatitis and investigate the penetrability of amikacin to chronic inflammatory prostatic tissues.

METHODS

A total of 180 male rats were randomly divided into a normal control group (NC, n=48), a chronic bacterial prostatitis group (CBP, n = 84) and a CBP treatment group (CBPT, n = 48). The prostates of the animals were injected with Xiaozhiling and E. coli respectively to make CBP and CBPT models. The animals of the CBPT group were treated with amikacin by intramuscular injection, their prostate tissues and sera isolated at 1-150 min after the treatment and detected for antibiotic activities, bacteria counts and pathological changes.

RESULTS

Obvious chronic inflammatory pathological changes including leukocyte invasion and fibre hyperplasia were observed and E. coli isolated from the prostate tissues of the rats in the CBP and CBPT groups, but no pathological changes, antibiotic activity and bacteria were detected in the the NC group. The numbers of E. coli in the prostate tissues markedly decreased with the time in the two model groups, 30 CFU/mg in the CBP rats at 28 days and 0 CFU/mg in the CBPT group at 10 days after the treatment. Obvious antibiotic activities were found in both the prostate tissues and sera at 2-150 min after the injection. No antimicrobial activities were detected at 12 hours after the treatment either in the sera or in the prostate samples. With the increase of the treatment time and decrease of the bacteria counts, the chronic inflammatory pathological changes were obviously alleviated in the CBPT group.

CONCLUSION

Rat models of CBP with chronic inflammatory pathological changes can be successfully established by direct injection of Xiaozhiling and E. coli into the prostate. Amikacin, given by intramuscular injection, can penetrate into the prostate of the CBP rat and produce an antibiotic activity equal to or higher than that of the sera, which may kill sensitive bacteria in the prostate and help to reduce the inflammatory pathological changes and repair the damage to the prostate tissues.