Changes in protein expression of NMDA glutamate receptor and Pannexin-1 channel in gastric antrum tissue of rats with type 2 diabetes and treated with insulin

Evidence shows that glutamate receptors play a role in the occurrence of gastrointestinal damage caused by diabetes. Therefore, in this study, the protein expression pattern of glutamate receptor N-methyl-D-aspartate (NMDA) and pannexin-1 (Panx-1) channel, which has an important functional relationship with glutamate receptors, in the stomach of type 2 diabetic rats were investigated. We also assessed the effect of long-term treatment with insulin on the possible changes of the mentioned proteins.

In this experimental study, 18 male Wistar rats weighing approximately 80-90 grams were randomly assigned into 3 groups (6 rats each): 1) control with standard diet, 2) type 2 diabetes: high-fat diet for 3 months + single dose of streptozotocin (35 mg/kg), and 3) type 2 diabetes + insulin treatment. The protein content of NMDA receptor as well as Panx-1 was detected using western blot method and compared among groups.

In the stomach of type 2 diabetic rats, the expression of Panx-1 protein was significantly decreased (P<0.001), while the expression of NMDA receptor (P<0.001) showed a significant increase. Insulin treatment improved the expression level of Panx-1 protein in diabetic rats, in addition, insulin treatment decreased the expression level of NMDA receptor in diabetic rats (P<0.05).

The present findings indicate important changes in protein levels of NMDA receptor and Panx-1 channel and their possible role in the occurrence of sensory-motor and secretory damage related to diabetes. The correction of the above changes may play a role in improving the functional damage caused by type 2 diabetes.