A detailed study of the urinary peptides in a patient with osteomalacia and hyperparathyroidism.

1. The urinary peptides and amino acids have been examined in a 28-year-old female with osteomalacia and severe parathyroid bone disease. Forty ninhydrin positive substances were identified. 2. These substances included nine hydroxyproline containing peptides of relatively simple composition. Of these eight contained 4-hydroxyprolineY two contained cis-3-hydroxyproline and one had trans-3-hydroxyproline. Two larger peptides which contained a high proportion of 4-hydroxyproline residues were also found. Free 4-hydroxyprolineY free hydroxylysine and a hydroxylysine complex were found. 3. Of the remaining twenty-six substances, which may not be derived from collagen, alaninol is reported as an urinary constituent for the first time, six are less common but have been reported previously whilst the remaining nineteen are well-known urinary constituents. 4. The significance of these findings in relation to collagen breakdown is discussed.