Abstract
The aim of this study was to find the effect of long-term food additive monosodium glutamate (MSG) on the tissue of pancreas. For this purpose, two treated groups of adult wistar rats were administered 15 mg/kg body weight for 30 and 75 days respectively. Immediately after sacrificing, specimens of pancreas were collected and fixed. Routine histological processes were carried out to prepare the specimens for light microscopy. Hematoxylin and Eosin, and Gomori aldehyde fuchsin stains were used. The study confirmed that the pancreas had a histological compensatory defense mechanism. In terms of exocrine units, the size of islets of Langerhans were increased due to increase the size of alpha and beta cells and the engorgement of the surrounding blood vessels. The exocrine acini neighboring to islets of Langerhans were engorged with secretion. After 75 days, fusion of some preexisting islets among the exocrine units were recorded. The study firstly focused the light on the pancreatic adipose tissue differentiation to give rise a newly–formed islets of langerhans. The alpha and beta cells of the islets had a well cytological architecture with apparent network of functional blood vessels. Creation of a new generation of beta cells induced by appetizer, may regarded as an important approach in the treatment of type 1 diabetes mellitus. The study concluded that, in small animals, the endocrine mass of pancreatic islets proportionate with the need of insulin. Moreover, adipose tissue act as endocrine tissue and may secreting the hormone insulin. The study declared a positive relationship between exocrine and endocrine units, when the pancreas was subjected to external stressful factor.

Key words: Rat, Pancreas, Adipose Tissue, Monosodium glutamate