Examination of the melatonin effects on duodenum in experimental diabetic rats

Diabetes Mellitus is a chronic metabolic disorder characterized by hyperglycemia. Due to the insulin deficiency or insulin defects, organism can not benefit enough from carbohydrate, fat and protein. Hyperglycemic condition increase free radicals because of glucose intoxication, therefore diabetes mellitus leads to oxidative stres in all tissues and organs. It would also cause a variety of symptoms in the gastrointestinal tract which is important for insulin secretion. The benefits of the use of antioxidants to improve oxidative stress has been shown in diabetes mellitus. Melatonin is known as the most powerful antioxidant to this day and use of it may be useful in diabetes for gastrointestinal system. This study aimed to investigate melatonin effects on duodenum in experimental diabetic rats. To this end, thirty two male rats which are eight weeks of age were divided into four groups. Diabetes mellitus group (D), diabetes mellitus and melatonin group (DM), melatonin group (M) and control group (C). D and DM groups was injected single dose of 60 mg/kg Streptozotosin intraperitoneally. Three days later blood glucose levels were measured from the tail vein. All animals were included in the study because blood glucose levels are above 200 mg/dl all of them. Afterwards melatonin administration was carried out everyday for six weeks in DM and M group 10 mg/kg intraperitoneally. Control group was injected only isotonic. After six weeks cervical dislocation was performed under anesthesia to animals and collected duodenal tissue samples by opening the abdominal cavity. Tissue samples were passed through routine histological procedures and 5 mm sections were taken and stained hematoxylin and eosin, alcian blue (AB), pariodic acid schiff (PAS) and alcian blue-periodic acid schiff. Histometric parameters; villus length, villus width and crypt depth, crypt diameter, tunica muscularis thickness, number of goblet cells, intestinal outer diameter, artery and vein diameter, the diameter of the Brunner's glands were measured to select well oriented ten villi and Brunner's glands on ten sections under computer assisted microscope. Secretion contents of goblet cells was studied on AB - PAS stained sections. PAS reaction severity of the villi and crypt was studied on PAS stained section and amount of acidic mucus in lümen was evaluated on AB stained sections. Data were analyzed with IBM SPSS Statistics 21 Version program. Statistical results showed significant differences between groups in terms of villus length, crypt depth, tunica muscularis thickness, number of goblet cells, intestinal outer diameter, vein diameter, the diameter of the Brunner's glands, secretion of goblet cells characteristic, PAS reaction severity of the villi and crypt, body weight changes, blood glucose level, hemoglobin A1c, amount of acidic mucus in lümen. Statistical results showed no significant differences between groups in terms of villus width, crypt diameter, artery diameter. Positive effects of melatonin were found in diabetes mellitus about duodenum histomorphology. Keywords; experimental diabet, rat, melatonin, duodenum