Abstract
Arbino rats were fed a casein diet, zein diet and non-protein diet, and the contents of gastrointestinal tracts were analyzed for 70% ethanol soluble nitrogen, and 4 free amino acids as described by Nasset (1955).
It was obserbed that all 4 amino acids were present in almost same rate throughout the test meals and the segments of intestine.
Therefore, these results suggested that endogenous amino acids were secreted into intestinal tracts during digestion and absorption of diets.
