Effect of insulin on the expression of intraocular vascular endothelial growth factor in diabetic rats.
BACKGROUND
To investigate the long-term effect of insulin on vascular endothelial growth factor (VEGF) of streptozotocin (STZ)-induced diabetic rats.


METHODS
Male Sprague-Dawley rats received intraperitoneal injections of STZ (60 mg/kg) to induce diabetes. The diabetic rats were divided into two groups: the poorly controlled diabetic group (4 U of Ultratard week) and the insulin-controlled group (2-8 U of Ultratard per day according to blood glucose level). The animals were sacrificed 4 months after diabetes induction. The intraocular fluids of four eyes from two rats were pooled together as one sample. VEGF was checked using an enzyme-linked immunosorbent assay (ELISA) kit.


RESULTS
There were eight rats in the poorly controlled diabetic group, 13 in the insulin-controlled group and 10 in the healthy group. The concentration of VEGF ranged from 70.72-164.89 pg/ml (mean, 99.60 +/- 31.37 pg/ml) in the poorly controlled diabetic group, 65.17-124.33 pg/ml (mean, 79.05 +/- 21.50 pg/ml) in the insulin-controlled group and 50.6-67.6 pg/ml (mean, 58.07 +/- 6.49 pg/ml) in the healthy group. There were statistical differences between groups (ANOVA, p < 0.001). The mean difference between the poorly controlled diabetic group and the insulin-controlled group was 20.55 +/- 9.61 pg/ml (p = 0.041).


CONCLUSIONS
The concentrations of VEGF in the two diabetic rat groups were higher than that in the healthy rat group. Insulin control reduced the rise of VEGF.
Kuo
Hsi-Kung
HK
Department of Ophthalmology, Chang Gung Memorial Hospital, Kaohsiung, Taiwan, R.O.C. d2767@cgmh.org.tw
Wu
Pei-Chang
PC
Kuo
Chien-Neng
CN
Chen
Yi-Hao
YH
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005123:Eye / Q000737:chemistry*; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis*
D001786:Blood Glucose; D007328:Insulin; D042461:Vascular Endothelial Growth Factor A; D013311:Streptozocin