1. In vitro evaluation of circadian patterns of bone collagen formation.
- Author
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Russell JE, Walker WV, Fenster RJ, and Simmons DJ
- Subjects
- Animals, Biological Transport, Active, Collagen metabolism, Male, Organ Culture Techniques, Osteoblasts physiology, Proline metabolism, Proline pharmacology, Rats, Rats, Inbred Strains, Bone and Bones metabolism, Circadian Rhythm, Collagen biosynthesis, Parathyroid Hormone physiology
- Abstract
The circadian patterns of bone collagen formation were studied in vitro to ascertain whether the biorhythmic profiles previously measured in vivo reflect true differences in collagen synthesis. Alteration of amino acid pool sizes did not negate the circadian-stage differences in bone collagen production. Evaluations of proline uptake and transport, as well as collagenous protein turnover, demonstrated that the intracellular assembly and secretion of bone collagenous protein during the dark span is truly decreased relative to that during the light period. It was further affirmed that PTH is essential for maintenance of the normal circadian collagen synthesis rhythms.
- Published
- 1985
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