Effect of Fasting and Refeeding on Pancreatic DNA Synthesis and Content 1

Summary These studies were designed to determine the effects of fasting and re-feeding on pancreatic DNA content and rates of [14C]thymidine incorporation into DNA. The following changes were observed following fasting for 2, 4, and 6 days or fasting for 6 days with refeeding for 1,2, and 3 days. Pancreatic weight decreased 8, 28, and 43% and then increased 23, 12, and 36%; DNA content decreased 2, 9, and 20% and then increased 6, 4, and 16%. [14C]Thymidine incorporation into DNA decreased 40, 69, and 86% and then increased 70, 267, and 511%. These studies show the influence of fasting and refeeding on rates of pancreatic DNA synthesis and on DNA content. Control studies demonstrated similar decreases in kidney, muscle, and spleen. These changes represent complex metabolic adaptive responses to food deprivation. The changes may be mediated in part by lack of substrate but also likely reflect alterations in the hormonal milieu. The authors wish to acknowledge the secretarial and editorial assistance of Ms. Jane Long and Ms. Hazel Wall.