Effects of noopept on cognitive functions and pubertal process in prepubertal rats with streptozotocin induced diabetes

Aim: Because of increased insulin resistance in adolescent T1DM, high dose insulin is used in treatment. High-dose causes hypothalamopituitarygonadal (HPG) axis deterioration and complications. New approaches to T1DM treatment are needed. Noopept researches suggested it might have anti-diabetic properties. We tried to determine the effects of noopept on pubertal DM. Material and Method: 60 prepubertal, 28 day-old, male, Sprague Dawley rats were divided to randomised 6 groups (n=10/group). i) control, ii) DM control, iii) noopept control, iv) DM-noopept, v) DM-insulin, vi) DM-insulin-noopept. Diabetes model was formed by 50 mg/kg streptozotosin on postnatal 28th day. Intraperitoneal 0,5 mg/kg noopept and 1 unit insulin was administered for 14 days in required groups. Regular glucose and weight measurements, puberty follow-up and MSL tests were performed. Hippocampus and hypothalamus were evaluated from the sacrificed rats histologically. Hypothalamic GnRH and kisspeptin were studied immunohistochemically. Serum; LH, FSH and insulin, hippocampal homogenate; NGF and BDNF levels were studied by ELISA tests. Results: The duration of delayed puberty in diabetic control and diabetes+insulin group was normalized by noopept administration (p<0.05). Blood glucose levels were lower in noopept-treated diabetic groups than diabetes-control group (p<0.05). HOMA-IR in insulin administered group decreased with noopept usage (p<0.05). Number of degenerated cells in the hippocampus of diabetic group was higher than other groups (p<0.05). GnRH immunoreactivity in diabetes+noopept group was higher than insulin and noopept co-administered group (p=0.018) There was no difference among kisspeptin, serum LH, FSH, hippocampal homogenate NGF and BDNF levels in groups (p>0.05). In spatial learning assessment, there was no difference in MSL (p>0.05). Conclusion: We think that noopept may have positive effect on pubertal T1DM. Key Words: Diabetes Mellitus, Puberty, Noopept, Cognitive Function, NGF, BDNF, GnRH, Kisspeptin