Effect of Pinealon on Learning and Expression of NMDA Receptor Subunit Genes in the Hippocampus of Rats with Experimental Diabetes

Abstract

Abstract—We studied the effect of the peptide drug pinealon (Glu-Asp-Arg) at doses of 50, 100, and 200 ng/kg on the training of rats in the Morris maze and the maintenance of the acquired skill after the development of experimental diabetes. We also studied the changes in the subunit composition of NMDA receptors in the hippocampus in these experimental models. In the Morris water maze, spatial learning was evaluated for 3 days, and pinealon was administered for 5 days following animal training. After training, animals were injected once with streptozotocin at a dose of 50 mg/kg of rat body weight. Estimation of the maintenance of the acquired skill and molecular studies (using real-time PCR) were performed on day 21 after modeling of experimental diabetes. It was shown that pinealon has a dose-dependent effect on the parameters studied. The most positive effect on the maintenance of the developed skill during streptozotocin-induced diabetes was observed after pinealon administration at a dose of 100 ng/kg. At this dose, we observed the smallest changes in the expression level of the Grin1, Grin2b, and Grin2d genes relative to the control values, as well as increased values of Grin2a/Grin2b ratio compared to diabetic groups treated with pinealon at dosages of 50 or 200 ng/kg.