Morphometric Analysis of the Collagen Changes Induced by Subcutaneous Injection of Interferon-gamma following Partial Unilateral Ureteral Obstruction in the Rat Kidney

Yun, Jong Min; Jung, Jung Yun; Kim, Kwang Myung

Abstract

PURPOSE: Interfenon-gamma(IFN-gamma) has been tried to decrease fibrosis in liver cirrhosis in the human and animals. To decrease collagen content in the partially obstructed kidney, we examined collagen changes by IFN-gamma after creating partial ureteral obstruction in the rat. We applied IFN-gammato the partially obstructed kidney and examined collagen contents in the renal cortex by morphometric analysis.
MATERIALS AND METHODS
In a total of 50 Sprague Dawley adult male rats(300-350gm), we created partial unilateral ureteral obstruction(PUUO). We divided rats into 5 groups(n=10 in each group): normal control, sham operation group, sham operation with IFN-gamma 4 weeks, PUUO 4 weeks, PUUO with IFN-gamma 4 weeks. IFN-gamma(LG Chemical, Korea) 100,000 IU was subcutaneously injected daily for 4 weeks from operation day 1 in the treated groups. The rats were sacrificed on the expected day and renal cortex was prepared for Masson`s trichrome special staining. With the image analyser, we calculated the relative ratio of collagen to renal cortex area randomly in each kidney.
RESULTS
Relative percent of collagen content of the normal control, sham-operation, and sham-operation with IFN-gamma treated groups were 2.42+/-0.53%(n=10), 2.62+/-0.53%(n=10), and 2.22+/-0.65%(n=10), respectively. While relative percent of collagen content of PUUO group, and PUUO with IFN-gamma treated group were 12.25+/-2.41%(n=5) and 7.14+/-3.43%(n=9) respectively. There was significant difference between those of last two groups.(p<0.05, Wilcoxon-rank sum test)
CONCLUSIONS
We applied interferon-gamma to the partially obstructed kidney and examined collagen contents in the kidney by morphometric analysis. From the above data, IFN-gammaseems to have a decreasing effect upon collagen content in the partially obstructed rat kidney.