Respiratory activity of different parts of small intestine in starved and fed animals.

Using the manometric method of Warburg the respiratory activity of tissue homogenates of the duodenum, jejunum and ileum was studied in starved and fed rats. The respiratory activity of mitochondria isolated from these parts of the small intestine was determined as well. The intensity of respiration was greatest in duodenal homogenates. The respiratory activity of jejunal homogenates was only slightly lower, while that of ileum homogenates was lowest. Oxygen utilization of intestinal homogenates from fed animals was much higher, particularly in the ileum, than in starved animals. During 50 minutes of incubation theu tilization of oxygen fell most rapidly in the duodenum and slowest in the ileum, and at the end of incubation the values obtained in starved and fed animals differed only slightly. Mitochondria showed similar patterns of oxygen uptake intensity as analogous homogenates, but the effects of starvation and feeding on mitochondrial respiratory activity differed -- in fed animals this activity was lower than in starvation.