Urinary excretion of hydroxyproline-containing peptides in man, rat, hamster, dog and monkey after feeding gelatin

1. 1. Quantities of free and peptide-bound amino acids were determined in urine of man, rat, hamster, dog and monkey fed normal and gelatin-containing diets. 2. 2. In man dietary gelatin resulted in an increased excretion of bound hydroxyproline without a change in free hydroxyproline excretion. 3. 3. In rats and hamster both bound and free urinary hydroxyproline was evaluated when the diet contained gelatin. 4. 4. The quantities of free and bound urinary hydroxyproline in the dogs and monkeys was the same whether the animals ingested a normal diet or a diet containing gelatin.