Nitrogen Content of Gastrointestinal Tracts of Rats During Absorptive Period. ∗

Abstract

Summary

1) The basal level of endogenously supplied nitrogen in adult rats is about 5 mg after 1 1/2 hours, and this level is unaffected by protein depletion. On feeding skim milk powder, 22–27% of the ingested protein disappeared from the gastrointestinal tract within 3 hours. Under the conditions of these experiments the alleged homeostatic action of the gut in supplementing amino acids to deficient protein meals may be only negligible. 2) No significant differences have been observed in gastric emptying time, rate of absorption, or digestion between skim milk powders dried at low or high temperature.