AIM: To observe the application of light emitting diode(LED)irradiation in rat retinal vascular endothelial cells with high glucose and its effect and mechanism on photobioregulation.

METHODS:Rat retinal vascular endothelial cells were randomly divided into three groups: normal control group, high glucose model group, high glucose model light emitting diode irradiation group, and cells in the high glucose model light emitting diode group began to use light emitting diodes in the incubator 48h after modeling. The cells are irradiated. MTT cell apoptosis experiment was used to detect the apoptosis rate of each group; laser confocal microscope was used to observe the changes of intracellular calcium in retinal vascular endothelial cells; Western blot was used to detect the phosphorylated serine-threonine kinase(P-AKT)protein in each group expression.

RESULTS: The apoptosis rates of normal control group, high glucose model group, and high glucose model light emitting diode irradiation group were 7.54%±2.67%, 31.69%±5.74%, and 21.65%±3.52%, respectively(P<0.05). In the normal control group, the cytoplasm with weak Ca²⁺ fluorescence showed green fluorescence with a pixel value of 192.65±50.54. In the high-sugar model group, the cytoplasm showed a stronger green fluorescence with a fluorescent pixel value of 710.69±100.38. The green fluorescent pixel value was 430.47±80.67, which was significantly higher than the normal control group, but significantly lower than the high-sugar model group. The intra-Ca²⁺ fluorescence pixel values in the three groups were statistically significant(P<0.05). The amount of phosphorylated serine-threonine kinase(P-AKT)protein in these three groups of cells was 10.26±2.47, 2.35±0.16, 7.46±1.64, respectively(P<0.05).

CONCLUSION: High-glucose environment inhibits the activity of threonine kinase pathway, which has an effect on calcium homeostasis of rat retinal vascular endothelial cells and promotes apoptosis. Low-intensity led irradiation can activate threonine kinase pathway and reduce the apoptosis rate caused by high glucose, which is of great application value.