Gender Difference in Structure and Function of Pancreatic Islet Cells in Prolonged Liquid Fructose Ingestion in Rats

Abstract

Daily consumption of high fructose in soft drinks and other processed foods is progressively rising in both adults and children, and it becomes a predisposing factor for the development of insulin resistance and type 2 diabetes. We have previously demonstrated that prolonged ingestion of liquid fructose (10% fructose solution) led to insulin resistance and hyperinsulinemia only in male but not female rats. However, it remains unknown whether ingestion of liquid fructose would lead to morphological alteration and function of the pancreatic islet cells. Thus, the present study examined the architecture and distribution of islets from liquid fructose-fed male and female rats. Male and female Sprague-Dawley rats were given either reverse osmosis water or liquid fructose for six weeks. The histological changes in size and number of pancreatic islets were assessed by hematoxylin-eosin staining. Insulin resistance and -cell function were demonstrated by homeostasis model
assessment index of insulin resistance (HOMA-IR) and -cell function (HOMA-), respectively. We found that a significant increase in plasma insulin levels observed in fructose-fed male rats was positively correlated with a higher number of oversized islets. Our current findings indicate that there is sex dimorphism in pancreatic islet structure and function in response to prolonged fructose ingestion. The present work provides further understanding of gender differences in the context of the pancreas relevant to fructose-induced metabolic dysfunctions.