Effect of diabetes mellitus on prostate and expression change of insulin-like growth factor-1 in prostate

Objective To investigate the impact of diabetes on the prostate and the expression of insulin-like growth factor-1 (IGF-1) in the prostate tissue in order to understand the pathological mechanism of diabetes on the prostate.Methods Thirty-five male Sprague-Dawley rats (200-250 g) were randomly divided into two groups:normal control group (NC,n =15),and diabetes model group (DM,n =20).After fasting for 12 h,the rat diabetic models were induced through intraperitoneal injection of STZ (65 mg/kg).Isochoric citric acid buffer solution was given in control group.Two groups were given the ordinary animal feed and adequate water.Nine weeks later,diabetic models were successfully established.The whole prostate was removed.The prostates wet weight without fascia and fat was measured and all specimens were fixed immediately.Using haematoxylin-Iraq red (HE) dyes,morphological changes of the prostate tissues in the diabetic rats were observed under microscope.The IGF-1 expression in the prostates was detetected by using immunohistochemical staining.SPSS 13.0 software was used to processe the experimental date.Results The prostate wet weight in diabetic group was obviously slighter than that in control group [(201.29 ± 24.81) mg vs.(934.15 ± 165.35) mg,P ＜ 0.01].The prostate index in diabetic group was obviously lower than that in control group (0.80 ±0.06 vs.2.47 ±0.34,P ＜0.01).Light microscopy revealed the pathological changes of the prostates in diabetic rats.The IGF-1 levels in the prostatic epithelia of diabetic group were significantly lower than in normal group group (5.33 ± 1.84 vs.3.00 ±1.92,P ＜ 0.01).Conclusion Diabetes can lead to the reduced prostste weight,the decreased prostate index,structure disarrangement of the prostate,which may influence the male fertility.The decrease of the IGF-1 expression in the prostate tissue may be one of the factors inducing prostatic lesions in diabetes. Key words: Diabetes ;  Prostate;  Prostate index ;  Insulin-like growth factor-1