Pattern of distribution of IGF-1 and EGF in pancreatic islets of type 2 diabetic patients.

Growth factors such as insulin growth factor-1 (IGF-1) and epidermal growth factor (EGF) play important roles in the regulation of cell metabolism in response to different internal as well as external stimuli. It is not clear how Type 2 diabetes mellitus influences the expression of these growth factors in the endocrine pancreas. The localization of IGF-1 and EGF was analyzed to determine the impact of Type 2 diabetes on the pattern of distribution of these growth factors in pancreatic islet cells. Pancreatic tissue samples retrieved, during pancreatectomy for pancreatic tumour, from patients with and without Type 2 diabetes were paraffin embedded. The tissue samples were chosen from non-neoplastic, clear excisional, margins. The expression of IGF-1 and EGF was investigated using immunofluorescence techniques. IGF-1- and EGF-immunoreactive cells were observed in many cells located in the central region of pancreatic islets. The percentage of islet cells expressing IGF-1 and EGF decreased significantly (P < 0.05) in diabetic patients compared to control. The number of human pancreatic islet cells expressing IGF-1 and EGF decreased significantly after the onset of Type 2 diabetes. These growth factors may play a role in the function of the endocrine pancreas and in the pathogenesis of the diabetes mellitus.