Expression of epidermal growth factor, basic fibroblast growth factor and insulin growth factor-1 and relation to myocyte regeneration of obstructed ureters in rats.
OBJECTIVE
To investigate the roles of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and insulin growth factor-1 (IGF-1) in the myocyte regeneration of obstructed ureters.


METHODS
The expression of EGF, bFGF, IGF-1 and proliferation cell nuclear antigen (PCNA) was studied immunohistochemically in 54 female Sprague-Dawley rats.


RESULTS
Tissue damage to the smooth muscle layer in the obstructed ureters was aggravated during the period of obstruction. The expression of EGF, bFGF and IGF-1 in myocytes was detected using the method of concurrent immunohistochemical staining. The expression of EGF, bFGF and IGF-1 in the smooth muscle layer was found from Day 14 after ligation. The expression of EGF, bFGF and IGF-1 increased to a peak on Day 21 and then declined. The expression of PCNA in the smooth muscle layer was also found from Day 14 after ligation and increased to a peak on Day 21. The expressions of EGF, bFGF and IGF-1 were significantly correlated with the expression of PCNA in the smooth muscle layer (r=0.7982, 0.6264 and 0.5840, respectively; p-values all <0.002). Co-expression of EGF, bFGF, IGF-1 and PCNA was determined using the method of double immunofluorescence staining. Co-expression of PCNA was observed in 34% of EGF-positive myocytes, 53.6% of bFGF-positive myocytes and 41.1% of IGF-1-positive myocytes at Day 21 post-ligation.


CONCLUSIONS
Expression of EGF, bFGF and IGF-1 may contribute to myocyte regeneration of damaged ureters in rats with obstructive uropathy.
Chuang
Yen-Hwang
YH
Department of Neurology, Kaohsiung Medical University, Kaohsiung, Taiwan.
Chuang
Wan-Long
WL
Huang
Shu-Pin
SP
Huang
Chun-Hsiung
CH
D000818:Animals; D004815:Epidermal Growth Factor / Q000096:biosynthesis*; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis*; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism / Q000502:physiology*; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration / Q000502:physiology*; D013997:Time Factors; D014517:Ureteral Obstruction / Q000378:metabolism / Q000503:physiopathology*
D018809:Proliferating Cell Nuclear Antigen; D016222:Fibroblast Growth Factor 2; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I