ISSN:
1432-0827
Keywords:
Corticosteroids
;
Collagen synthesis
;
Bone cells
;
Cartilage cells
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
,
Physics
Notes:
Summary Deflazacort is a new synthetic glucocorticoid which is an oxazoline derivative of prednisolone. In previous studies, it was shown that deflazacort, depending on the test model used, not only showed considerably more antiinflammatory potency than prednisolone in animals but also caused less deleterious effects on bone mineral metabolism than equivalent amounts of other glucocorticoids in man. In this study, we have compared the effects of deflazacort with those of dexamethasone on the synthesis of collagen in various rat bone cell populations and chondrocytes. Three bone cell populations were prepared by sequential time-dependent collagenase treatment of 1-day-old rat calvaria. Each cell population was further purified on a Percoll gradient (10–90%) yielding three populations of which two are different in alkaline and acid phosphatase and response to parathyroid hormone. A 3-day treatment of bone cell populations with deflazacort and dexamethasone (10−11-10−5 M) revealed that both glucocorticoids, although at different concentrations, inhibited collagen synthesis. 21-desacetyl-deflazacort (5β, 11β, 16β)- 11,21-dihydroxy-2′-methyl-5-H-pregna-1-enol[17,16-d]oxazole-3,20-dione), the presumably active form of the steroid, which is formedin vivo after administration, produced nearly identical results as its precursor. Glucocorticoid concentrations at which inhibition was initially observed were 10−9 M and 10−7 M for dexamethasone and deflazacort respectively. Inhibition of collagen synthesis was significantly impaired only in cells isolated from bone during early tissue digestion, and not in those obtained during extensive collagenase treatment. Chondrocytes isolated from articular cartilage of 3-month-old rabbits and grown in primary cultures did not respond to either steroid. However, when passed and grown in secondary culture, collagen synthesis was inhibited considerably more by dexamethasone than by deflazacort. It is apparent that both deflazacort and dexamethasone, although at different concentrations, inhibit collagen synthesis in a differential manner. The lesser deterrent effect of deflazacort may be of clinical importance.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02405310
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