ABSTRACT
PURPOSE: 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. MATERIAL AND METHODS: 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 The experimental animals were withdrawn from the study 1 and 4 months after the start of insulin therapy.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. RESULTS: 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). CONCLUSION: 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.
Subject(s)
Alloxan , Diabetes Mellitus , Animals , Aqueous Humor , Eye , Insulin , Rats , Vascular Endothelial Growth Factor AABSTRACT
PURPOSE: To study the effect of insulin therapy on the concentration of vascular endothelial growth factor A (VEGF-A) in the intraocular fluid of rats with alloxan model of diabetes mellitus. MATERIAL AND METHODS: The experiment was conducted on 80 mongrel rats. In 65 rats, the alloxan model of diabetes mellitus was simulated by a single intraperitoneal injection of 100 mg/kg alloxan hydrate saluted in 0.4 ml of citrate buffer. 72 hours after intraperitoneal administration of alloxan monohydrate, these animals were divided into 2 groups. The main group (group 1) consisted of animals with alloxan model of diabetes mellitus, who started daily single intraperitoneal administration of prolonged-acting insulin at a therapeutic dose of 0.9 U/kg Body weight. The comparison group (group 2) consisted of animals with alloxan model of diabetes mellitus who did not receive specific therapy. 15 healthy rats constituted the control group (group 3). Experimental animals were removed from the study on day 31 of insulin therapy. The concentration of VEGF-A was determined in 80-90 µl of intraocular fluid collected from both eyes of each animal. RESULTS: In the main group, the median of VEGF-A concentration [25th; 75th percentiles] in the intraocular fluid was 140 [136; 210] pg/ml, which is 1.94 times higher than in the comparison group (72 [58; 86] pg/ml) and 1.84 times higher than in the control group (76 [62.5; 88] pg/ml). The concentration of VEGF-A in the intraocular fluid in the main group was statistically significantly higher, as compared with the comparison group (pm-u<0.0004), and compared with the control group (pm-u=0.0045). The comparison group had no statistically significant differences when compared with the control group (pm-u=0.9979). CONCLUSION: Insulin therapy for 31 days increases the concentration of VEGF-A in the intraocular fluid of rats with alloxan model of diabetes mellitus.
