Augmented mitogenesis in normal connective tissue cells following mast-cell secretion in diabetic rats

We studied the proliferative response of fibroblasts and mesothelial cells in the mesentery of streptozotocin-diabetic rats with diabetes of 4 weeks duration, after local mast-cell secretion elicited by compound 48/80. Free peritoneal mast cells from the diabetic animals showed no altered content of 5-HT, histamine, or heparin, and the concentration of histamine in the mesentery and its release by 48/80 were roughly similar in non-diabetic and diabetic animals. The diabetic animals showed an increased responsiveness in this strictly mast-cell dependent mitogenesis, as measured by specific DNA activity and the mitotic index, regardless of whether the animals were insulin-deficient or treated for 2 h with fast-acting insulin.