Changes in serum and prostatic zinc concentrations in rats after intraprostatic injection of zinc: Comparison of two forms of zinc delivery.
BACKGROUND
We investigated changes in zinc concentrations in serum and prostatic tissue after an intraprostatic injection of zinc, and compared two forms of zinc delivery: solution and liposome.


METHODS
Ninety-six male Wistar rats were used in the study (24 controls, 72 test rats). The test animals were randomly divided into two groups and were injected intraprostatically with 2 mL of 0.04 mol/L zinc sulfate according to the form of zinc delivery. Nine rats in each test group were sacrificed 1 day, 7, 14 and 28 days after injection, and 24 normal rats were injected intraprostatically with 2 mL of distilled water as controls. Serum and prostatic zinc concentrations of each group were measured by inductively coupled plasma atomic emission spectrometry. Blood chemistries, routine urinalysis, urine culture and histopathologic examination were also performed.


RESULTS
Serum zinc concentrations did not change significantly after the intraprostatic injection of zinc. Prostatic zinc concentrations were found to be significantly greater (P < 0.05) in zinc-injected groups than in the control group. The intraprostatic injection of zinc solution and zinc liposome increased zinc levels in both ventral and dorsolateral lobes significantly. Prostatic zinc levels increased progressively following injection, reaching a peak level in 7 days and maintaining a high value throughout the experimental period. The prostatic zinc level of the 1-day zinc liposome group was higher than that of the 1-day zinc solution group, while no significant difference was observed between the solution and liposome group in 7, 14, 28 days. No abnormal findings were observed in any of the laboratory and histopathologic examinations; however, an acute inflammatory response was observed in the 1-day groups.


CONCLUSIONS
These findings suggest that an intraprostatic injection of zinc in normal rats increases and maintains the prostatic zinc level for at least 4 weeks without causing any systemic or local toxicities. These findings suggest the potentially important clinical applicability of local zinc to the treatment of chronic prostatitis.
Cho
Yong-Hyun
YH
Department of Urology, College of Medicine, The Catholic University of Korea, Seoul and Amore Pacific Corporation R & D Center, Yongin, Korea.
Lee
Seung-Ju
SJ
Lee
Ji Youl
JY
Kim
Sae Woong
SW
Kim
Jung Ju
JJ
Lee
Woo Young
WY
Yoon
Moon Soo
MS
D000818:Animals; D007267:Injections; D008081:Liposomes; D008297:Male; D011467:Prostate / Q000737:chemistry* / Q000473:pathology; D051381:Rats; D012996:Solutions; D015032:Zinc / Q000008:administration & dosage* / Q000032:analysis* / Q000097:blood
D008081:Liposomes; D012996:Solutions; D015032:Zinc