Objective   To investigate the chronic inflammation causing effect of nanobacteria (NB) on the prostates of SD rats

and to provide experiment evidence for etiology of type Ⅲ prostatitis.      Methods    Forty adult

male rats were divided into model group (16 rats)

treatment group (8 rats) and control group (16 rats) at random. The rats in model group and treatment group were reproduced by infusing NB suspension transurethrally

and the animals of control group received an infusion of normal saline. After 4 weeks

WBC

lecithine and pathological changes of prostates were observed in model group (8 rats) and control group (8 rats). Tetracycline (100 mg·kg

-1

·d

-1

) was administered to tr

eatment group

and distilled water were given to other groups respectively for 4 weeks. Then all rats were sacrificed

and the same detections were done as before. NB from prostates of animal were re-isolated

cultured and identified.    Results   After 4 weeks

chronic inflammation were observed in model group. WBC became significantly higher and lecithine of prostates were lower in model group than in control group (P0.05). After 8 weeks

relieved chronic inflammation

decreased WBC and increased lecithine of prostates were observed in treatment group comparing with model group. There was significant difference in model group with control group and treatment group(P0.05)

and no difference was seen between control group and treatment group(P0.05). The positive cases of NB were 16 in model group

and none in control group.     Conclusion   Nanobacteria causes chronic inflammation in SD rat prostates. NB maybe the etiological agent of type Ⅲ prostatitis. Anti-NB treatment by tetracycline is effective for this inflammation.