Although studies on the degradative metabolism of hydroxyproline have revealed that this amino acid is converted at least in part to glutamic acid (I-G), knowledge of the intermediates in this conversion and of other products of hydroxyproline metabolism is not yet complete. In the course of experiments on the metabolism of hydroxyproline, it was observed that incubation of hydroxyproline with ...

1. The earlier observation (Woessner, 1969) of oestradiol inhibition of collagen breakdown is confirmed and extended. Administration of 100mug of oestradiol-17beta/day to parturient rats strongly inhibits the loss of collagen from the involuting uterus. Three experiments show that this effect is due to an inhibition of collagen degradation rather than to a stimulation of collagen synthesis. 2. ...

Beginning with the report of Ziff, Kibrick, Dresner, and Gribetz (2), evidence accumulated in recent years has indicated that urinary hydroxyproline excretion reflects collagen metabolism, since collagen is the only protein in the body that contains hydroxyproline in significant amounts (3). Ziff and co-workers, observing that the excretion of this amino acid in peptide form was greater in chil...

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-hydro...

Cardiac hypertrophy was induced in rabbits by injecting either thyroxine or isoprenaline or by surgically constricting the abdominal aorta. An increase in heart weight was associated with a change in the lactate dehydrogenase isoenzyme pattern and an increase in fibrosis (as measured by hydroxyproline concentrations). Isoprenaline treatment led to a moderate increase in heart weight, a marked d...

Plasma hydroxyproline fractions--free-plus-peptide and free--were determined by a method involving centrifugal ultrafiltration and the procedure of Kivirikko et al. [Anal. Biochem. 19, 249 (1967)]. Within- and between-day precision (CV) for the combined fractions was 4--5% and 2.8--6%, respectively. Mean analytical recoveries of free hydroxyproline were 95.2% (87--109%) in the normal range, and...

There has been a great need for a satisfactory method for the determination of hydroxyproline to facilitate the study of the composition of proteins. Lang (1) and Waldschmidt-Leitz and Akabori (2) developed a calorimetric estimation involving oxidation to pyrrole with sodium hypochlorite and color formation with isatin or p-dimethylaminobenzaldehyde. However, oxidation was said to be incomplete...

Background : Bone resorption can be assessed by measuring plasma tartarate resistant acid phosphatase and urinary excretion of collagen degradation products: Hydroxyproline,Hydroxylysine glycosides,pyridinium crosslinks and associated peptides. We compared the excretion of Hydroxyproline in women of premenopausal age group to those of post menopausal age group and found a significant difference...