The Effects of Early Diabetes on Duodenal Alterations in the Rats

Diabetes mellitus (DM) mainly affects functional changes in the duodenum, which plays an important role in the digestion and absorption of food. The impairment of duodenal function contributes to malnutrition, abdominal bloating and pain in diabetic patients. Thus, this study aimed to investigate the histological alterations and quantitative measurements of duodenal structures in the early stage of streptozotocin (STZ)-induced diabetic rats. Eight male Sprague–Dawley rats were divided into three control and five diabetic rats. Diabetes was induced by a single intraperitoneal dose of 60 mg/kg STZ. After four weeks of diabetic induction, the duodenum was prepared for histological study and morphometric analysis. In diabetic rats, there were deformed villi with disrupted surface epithelium and mildly distorted shapes of crypts, together with an increase in villus height and crypt depth. The epithelial cells detached from their underlying basement membrane. The goblet cells decreased in number, whereas an increased number of Cellula panethensis (Paneth cells) with pale-stained eosinophilic granules occurred in the DM group. A diabetic thickened submucosal layer was observed as enhanced duodenal glands (Brunner’s glands) hypertrophy and collagen accumulation. These findings indicated that histopathologic lesions of the duodenum developed in the early stage of diabetes. The destruction of villi, crypts, and epithelium may affect digestion and absorption. The structural changes in goblet and Cellula panethensis and duodenal glands may be associated with malfunction to protect duodenal mucosa from bacteria and stomach acid. These conditions can worsen the quality of life in diabetic individuals, leading to complications such as maldigestion, malabsorption, and duodenal ulcer.