Systemic basic fibroblast growth factor induces favorable histological changes in the corpus cavernosum of hypercholesterolemic rabbits

Purpose: Hypercholesterolemia causes erectile dysfunction that is associated with abnormalities in vascular smooth muscle and endothelial cells. We determined the effects of basic fibroblast growth factor (bFGF) on corporeal tissue in hypercholesterolemic rabbits. Materials and Methods: A total of 16 New Zealand White rabbits were fed a 1% cholesterol diet for 6 weeks and were randomly divided into 3 groups. Group 1 (5 rabbits) received 2.5 mug recombinant bFGF intravenously once and again 3 weeks later. Group 2 (6 rabbits) received 2.5 mug bFGF intravenously once and placebo 3 weeks later. Group 3 (5 rabbits) received placebo intravenously each time. Rabbits were continuously fed a 1% cholesterol diet and sacrificed 3 weeks after the last treatment. Smooth muscle, endothelial cell and collagen content were assessed by immunohistochemistry and histochemical staining of corporeal tissue. Vascular endothelial growth factor (VEGF) protein and mRNA expression were assessed by enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction. Results: Corporeal smooth muscle content was greater in groups 1 and 2 (35.24% +/- 4.25% and 24.79% +/- 3.39%, p < 0.01) vs group 3 (19.68% +/- 2.94%, vs groups 1 and 2 p < 0.001 and < 0.05, respectively). Endothelial cell and collagen content were similar among the groups. VEGF protein was increased in group 1 vs group 2 (97.90 +/- 26.00 vs 57.03 +/- 14.99 pg/ml, p < 0.01) and vs group 3 (39.93 +/- 15.08, p < 0.01). There was no statistical difference between groups 2 and 3. VEGF mRNA expression was similar among the groups. Conclusions: Systemic bFGF increases smooth muscle content and VEGF protein in hypercholesterolemic rabbit corporeal tissue.