Concentration of VEGF-A in the intraocular fluid of rats with alloxan model of diabetes mellitus

Abstract

To study the changes in the concentration of vascular endothelial growth factor A (VEGF-A) in the intraocular fluid (IOF) of rats with alloxan model of diabetes mellitus (DM) on insulin therapy at different time points. The alloxan model of DM was simulated in 197 rats by a single intraperitoneal injection of 100 mg/kg alloxan hydrate. The animals were divided into 3 groups 7 days after administration of alloxan hydrate. The main group consisted of animals with alloxan model of DM, which begain receiving single daily intraperitoneal injections of insulin at a dose of 0.9 U/kg body weight. The comparison group included animals with alloxan model of DM, which did not receive the therapy. The control group consisted of healthy animals. The experimental animals were withdrawn from the study 1 and 4 months after the start of insulin therapy. The concentration of VEGF-A was determined in 80-90 μL of intraocular fluid collected from both eyes of each animal. At 1 month, the VEGF-A concentration in the intraocular fluid in the study group (n=17; 140 [136; 210] pg/mL) was statistically significantly higher than in the comparison group (n=20; 72 [58; 86] pg/mL; pm-u<0.0004), and in the control group (n=16; 76 [62.5; 88] pg/mL; pm-u=0.0045). The comparison group did not have statistically significant differences from the control group (pm-u=0.9979). At 4 months, the VEGF-A concentration in the intraocular fluid in the study group (n=18) was 84.8 [61.1; 93.2] pg/mL, in the comparison group (n=16) - 66.4 [54.4; 73.75] pg/mL. The VEGF-A concentration in the intraocular fluid in the study group at 4 months was statistically significantly lower than in the study group at 1 month (pm-u<0.0044). Insulin therapy causes a statistically significant increase in the concentration of VEGF-A in the intraocular fluid of rats with alloxan model of DM after 1 month, but after 4 months of the therapy the VEGF-A concentration falls back to the initial values.