Faculty Collaboration Database

Stimulation of cartilage inorganic pyrophosphate elaboration by ascorbate. Matrix 1991 Aug;11(4):276-81

Date

08/01/1991

Pubmed ID

1656174

DOI

10.1016/s0934-8832(11)80235-0

Scopus ID

2-s2.0-0025788687 (requires institutional sign-in at Scopus site)   23 Citations

Abstract

Ascorbate (0-500 microM) stimulates synthesis and secretion of collagen by cartilage explants in a dose-dependent fashion as estimated by [3H]proline incorporation. Concurrent elaboration of inorganic pyrophosphate (PPi) parallels [3H]proline incorporation (less than 0.001, Wilcoxon rank sum). The effect on proline and PPi is abolished by ascorbate oxidase. Another reducing agent, Vitamin E, did not promote PPi accumulation about cartilage. Inhibitors of collagen synthesis, including monensin, tumor necrosis factor alpha, and 2',2'dipyridyl also inhibited PPi elaboration. Cycloheximide (1 micrograms/ml) inhibited the ascorbate stimulated PPi elaboration 54% but did not attenuate the secretion of PPi by unstimulated cartilage. Cosecretion of collagen and PPi by chondrocytes may explain these results. Moreover, at least two pathways exist for PPi elaboration, a cycloheximide sensitive path and another independent of new protein synthesis.

Author List

Ryan LM, Kurup I, Cheung HS

Author

Lawrence M. Ryan MD Emeritus Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

2,2'-Dipyridyl
Animals
Ascorbic Acid
Cartilage
Collagen
Culture Techniques
Cycloheximide
Diphosphates
Dose-Response Relationship, Drug
Monensin
Proline
Pyrophosphatases
Swine