The pancreatic angioarchitectural changes in alloxan induced-diabetic rat

Abstract

The present study deals with the angioarchitectural changes in the pancreas of alloxan induced diabetic rat. Twenty adult Fischer rats of both sexes weighing between 200 and 300 g were used. They were divided into three groups. The first group was for normal control. The animals of the second group were subjected to the alloxan induced diabetes. The third group were also injected with alloxan and after their blood sugar increased to or over three folds of normal level, they were daily injected with insulin. The estimations of glucose in urine and blood were made daily by using urinalysis control strip and glucostrip, respectively. The LM, TEM and vascular corrosion cast techniques were employed to study the pancreas. There was no significant difference between the pancreases of alloxan induced diabetic rat and those of alloxan induced diabetic rat with insulin treatment. Light and electron microscopic studies reveal that the majority of A and D cells locate at the peripheral area of the islets of Langerhans whereas the B cells occupy the central region. The degenerative changes could be observed in the B cells as the rough endoplasmic reticulum which transforms into a fingerprint like structure following by becoming fragmentation. The dilatation of golgi bodies with marked degranulation are also evident. Noteworthy, the large continuous capillary or collecting venule as well as a reduplication of basement membrane of the dilated vessels in ischemic area of the islet are observed. However, A and D cells are apparently unharm. In the pancreatic acini of diabetic rats, the varying sizes of dilated blood vessels are observed with light microscopy. The autophagic vacuoles, lipid droplets, fragmentations of rough endoplasmic reticulum together with the decrease of zymogen granules are much frequently found in diabetic rats when compared to those of controls. With SEM of vascular corrosion cast technique, the islet blood vessels are notably dilated. In addition, the blood vessels in the acini of the diabetic pancreas are also with tortuosity, dilatation and sinus-like structures. It should be noted that, the histopathology of the pancreas of the alloxan induced diabetic rat treated with insulin is practically the same as the alloxan induced diabetic rat without insulin treatment. The angioarchitectural changes in the pancreas may be a distinctive characteristic of diabetic rat.