PERCHLORIC AND TRICHLOROACETIC ACIDS AS PRECIPITANTS OF PROTEIN IN ENDOGENOUS ILEAL DIGESTA FROM THE RAT

The efficacy of perchloric and trichloroacetic acids as precipitants of protein from endogenous digesta collected from the distal ileum of the laboratory rat was evaluated. Twelve 190‐g male rats were fed a protein‐free diet and samples of ileal digesta were collected after slaughter. The digesta were pooled, and subsamples were treated with PCA or TCA or were left untreated. For both precipitants more than half of the total nitrogen (N) remained in solution post‐precipitation, and for the PCA and TCA treatments respectively at least 35 and 69% of the supernatant N was in the form of soluble protein. The amino acids (after acid hydrolysis) having the highest concentrations in the supernate are known to be abundant in the mucoproteins. Around 6.4 and 9.8% of the supernatant N was in the form of non‐amino N (creatinine N + urea N + ammonia N) for the PCA and TCA treatments respectively. Copyright © 1990 John Wiley & Sons, Ltd