Macro- and microscopic analysis of the fasting intestine. A) Change in whole-body and intestinal weight during fasting as percentage of the control. Asterisks label significant changes in weight compared to the fed condition. The line represents the daily percentual change in body weight. B) Histology of representative intestinal samples at 0 and 72 hours of starvation (left and right panel, respectively) stained with hematoxylin and eosin (upper panels), carbamoylphosphate synthetase (middle panels), or Alcian blue (lower panels). Zoomed-in regions show blue-stained goblet cells. On the upper and middle panels bars represent 0.5, and on the lower Alcian blue-stained panel 0.1 mm.