Quantitative Radioautographic Study on 3H-Leucine Uptake of Peri- and Tele-Insular Acinar Cells of the Pancreas in Normal and Streptozotocin-Diabetic Mice.

Abstract

The uptake of 3H-leucine by peri- and tele-insular acinar cells of the pancreas was analyzed quantitatively 60 min after the intraperitoneal injection of 3H-leucine in normal and streptozotocin-diabetic mice. A large tissue sample was analyzed and the grain density was counted with a color image analyzer equipped with a computer. The radioactivity was expressed as number of silver grains per acinar cell as well as per unit area of acinar tissue. In normal mice, the radioactivity in peri-insular acinar cells was 43% greater than in tele-insular acinar cells. The intercalated ducts associated with the former also showed a larger number of silver grains. In streptozotocin-diabetic mice, the uptake of 3H-leucine in peri- and tele-insular acinar cells was almost similar. The estimate of mean acinar cell profile area was 30% larger in the peri-insular acini of normal mice, while no difference was observed between the estimates of peri- and tele-insular acinar cells of diabetic mice.These results confirm previous reports that the B cell serection plays a certain role in the protein synthesis of pancreatic acinar cells, especially for the cells of peri-insular acini.