Objective To assess fibroblast growth factor-2 (FGF2/bFGF), which is import
ant in the development and maintenance of the normal prostate and in the de
velopment of human benign prostatic hyperplasia (BPH) and prostatic carcino
ma, in an animal model of experimentally induced diabetes.
Materials and methods Using Western blotting and immunohistochemical analys
es, the expression of FGF2 in prostates from several groups of rats was inv
estigated. Rats had diabetes for 8 or 16 weeks (induced by intravenous inje
ction with 65 mg/kg streptozotocin); rats were also treated with insulin (s
tarting 8 weeks after the induction of diabetes, for 8 weeks), and two furt
her groups acted as age-matched control rats. Immunohistochemical markers f
or smooth muscle (alpha-actin) and epithelium (cytokeratin) were used to di
stinguish different cell types in adjacent prostatic sections.
Results Diabetic rats had smaller prostates and lower serum testosterone le
vels than their controls; insulin treatment of diabetic rats increased pros
tatic size and testosterone levels. As shown by Western blotting, diabetes
caused greater FGF2 expression than in controls, whereas reverse-transcript
ase polymerase chain reaction studies showed similar levels of prostatic FG
F-2 mRNA in all groups. Immuno-histochemical studies showed that FGF-2 was
expressed in both stromal and epithelial components of the rat prostate. Fu
rthermore, although the expression of FGF2 was higher in epithelial than st
romal cells in control prostates, it was distributed uniformly in the diabe
Conclusion The differences in the level of expression and pattern of distri
bution of FGF2 suggests a potential role for FGF2 in the changes observed i
n prostatic growth in diabetic rats.