Labeled @entity1521 from incubation media has been shown to be incorporated into living bone matrix collagen in vitro. @entity720 is released from fresh bone slices in similar systems in a characteristic curve against time. This @entity720 is derived from three distinct sources, each of which may be separately quantitated. Part of the total represents passive solubilization of matrix collagen, part is derived from new synthesis of soluble collagen occurring in vitro, and the remainder is released by cell-mediated resorptive action. The latter two processes are linear with time up to 8 hr; the former decays to zero at about 2 hr. Consequently, rates of collagen synthesis and of new collagen deposition and resorption can be quantitated simultaneously in the same system. The ability to measure these parameters of bone collagen metabolism provides methods both for the accurate evaluation of organic matrix resorption in vitro and for the accurate measurement of rates of collagen synthesis and collagen deposition. The application of the method is illustrated using @entity461 and @entity175 . @entity461 diminishes collagen synthesis and stimulates collagen resorption. It reduces slightly the deposition of newly formed collagen in stable matrix. The net effect of these changes is to produce a marked negative balance. It does not significantly affect the solubility of matrix collagen. @entity175 does not affect collagen synthesis or its deposition. It causes a marked fall in resorption rate. It has no effect on matrix collagen solubility. The net effect is to produce a marked positive balance of matrix collagen.

Bone matrix turnover and balance in vitro. I. The effects of XXXX and @entity175 .

@entity1521 :: ('CHEBI:26271', 'Chemical') :: ['proline'] @entity175 :: ('MESH:D002116', 'Chemical') :: ['thyrocalcitonin', 'Thyrocalcitonin'] @entity720 :: ('CHEBI:18095', 'Chemical') :: ['Hydroxyproline', 'hydroxyproline'] @entity461 :: ('5741', 'Gene') :: ['parathyroid hormone', 'Parathyroid hormone']
@entity461 :: (5741,Gene) :: ['parathyroid hormone']
