Morphological Observations on Spontaneous Pancreatic Islet Changes in Rats

Abstract

A spontaneous lesion of the islet of Langerhans characterized by fibrosis and enlargement is described in the aging albino rat, occurring almost exclusively in males. Further studies are in progress to define the histogenesis, endocrine aspect and functional significance of this lesion.

The Effects of Ad Libitum Overfeeding and Moderate and Marked Dietary Restriction on Age-Related Spontaneous Pancreatic Islet Pathology in Sprague—Dawley Rats

“…In SD rats, the age-related morphological changes in pancreatic islets have been associated with metabolic alterations: from 3.5 to 17 months, progressive islet cell hyperplasia and brosis correlated with increased triglycerides, cholesterol, and glucose (8), and at 12 months islet brosis and enlargement was associated with hyperinsulinism and obesity (17,18,48). In this study insulin serum levels increased in females only, from 13 to 53 weeks.…”

Immunohistochemical localization of insulin in nesidoblastosis of rat pancreas.

“…The pancreatic endocrine cells appear to be derived from the same pool of epithelial cells that forms the exocrine tissue. A spontaneous lesion of the islet of Langerhans characterized by fibrosis and enlargement was described in the aging rats, occuring almost exclusively in males (2). Mild hyperplasia and profound elevation of serum immunoreactive insulin were induced by glucocorticoid injection for 1 to 3 weeks in subhuman primates (3) .…”

Age changes in the canine pancreas: histomorphological, electron microscopic, and biochemical study

“…The globular, uninterrupted cellular structure was transformed by increased collagen and reticulin into a branching multinodular conglomerate where groups of endocrine cells often situated around sinusoidal spaces were traversed and transected by wide bands of fibrous tissue. Hajdu and Rona (1967) noted that the intra-insular sclerotic process appeared to destroy and replace the islet parenchyma in the more severe cases. The intrainsular fibrosis was accompanied by an islet enlargement in 90% of the cases, indicating a close association between these two processes.…”

“…Hajdu and Rona (1967) attributed histogenesis of the fibrosis to the perivascular stromal elements, and the cellular proliferation to the duct epithelium.…”

“…Seifert (1954) reported the number of A cells to increase after the age of 50 years. Hajdu and Rona (1967) have studied pancreatic changes in 500 untreated, nonbreeder male and female mice. They reported that while the young animals and all female groups showed relatively uniform islets of Langerhans in regard to size and shape, males over 40 weeks old showed marked variation in the size and shape of th%;islets.…”