Effects of generated trans-arachidonic acids on retinal capillary during nitrative stress in diabetic rats

To investigate whether the trans-arachidonic acids (TAAs) change in diabetic conditions and the effect on capillary cells and its possible mechanism.

Diabetes was induced by intraperitoneal injection of streptozotocin at 60 mg kg(-1) body weight. The amount of TAAs and arachidonic acid (AA) in serum of diabetic rats was measured by the gas chromatography and mass spectrometry method and the ratio of the peak area of TAAs to AA with a selected ion of 79 was estimated by group t test. The expression level of thrombospondin-1 (TSP-1) in the retina was examined by Western blot. The pericyte apoptotic index was investigated by flow cytometry.

The ratio of TAAs to AA significantly increased in serum at the time points of 8, 12 and 16 weeks after streptozotocin induction (p < 0.05). The expression of TSP-1 in the retina of diabetic rats elevated with longer duration of diabetes (checking the time points of 2-, 4-, 8-, 12- and 16-week diabetic rats). The expression of TSP-1 tended to be physiologically elevated in relation to age but less significantly than in the diabetic group. TAAs could not induce the apoptosis of retinal pericytes (p > 0.05).

TAAs were generated associated with nitrative stress in diabetic rats and a possible mechanism of microvascular injury exits in diabetic conditions.