High levels of prostatic
zinc are associated with prostatic antimicrobial activities and are depressed in patients with chronic
prostatitis. We investigated the inhibition of bacterial growth in the rat prostate with chronic
prostatitis after intraprostatic injection of
zinc and compared two different types of
zinc delivery. Ninety male Wistar rats were used in the study. Experimental
chronic bacterial prostatitis was induced by instillation of bacterial
suspension (Escherichia coli 10(8) per ml) into the prostatic urethra. Animals were followed for 4 weeks and then injected intraprostatically with either 0.2 ml of
zinc liposome (ZL) or
zinc solution (ZS) (0.04 M
zinc sulphate) or 0.2 ml of
phosphate-buffered saline (PBS) for the controls. Ten rats in each group were sacrificed 4, 6 and 8 weeks after injection. The inhibition of
inflammation and its consequences were analyzed microbiologically and histologically. Prostatic
zinc concentrations were measured by inductively coupled plasma atomic emission spectrometry. Microbiological culture of the prostates demonstrated bacterial growth inhibition by the intraprostatic injection of
zinc. The average
infection rates and mean log(10) cfu/g of the
zinc-treated groups were significantly lower than those of the controls. The histopathology showed resolving
prostatitis in
zinc-treated groups compared with the controls. Prostatic
zinc levels were higher in the
zinc-treated groups than in the controls 4 and 6 weeks after
zinc injection (P<0.05). However, the ZL and ZS groups were found to be effectively identical in terms of prostatic
zinc levels, bacterial cfu, and histological findings throughout the experiment period. The intraprostatic injection of
zinc inhibited bacterial growth by increasing
zinc levels in the rat
prostatitis model. Our results suggest that the local application of
zinc to the prostate may be a new treatment for
chronic bacterial prostatitis at the point of its pathogenesis.