Alterations in collagen metabolism in heart and kidney on dexamethasone administration in rats.

ABSTRACT

Total collagen content in heart decreased significantly till day 8 of dexamethasone (Dex 2.5 mg/kg week; s.c. for 2 weeks) treatment and increased on withdrawal of Dex. Acid soluble collagen content in heart decreased till day 12 of Dex treatment, reached normal level on day 16 of Dex treatment and exhibited an increase thereafter. Pepsin solubilized fraction in heart also behaved similarly as the acid soluble fraction, but reached normal level on Dex withdrawal. The total collagen content and the acid soluble collagen in kidney decreased significantly throughout treatment as well as on Dex withdrawal whereas, the pepsin solubilized collagen fraction in kidney exhibited a significant increase from day 8 of Dex treatment and the level was maintained throughout the experiment. Incorporation of 14C-proline in both, heart and kidney was found to be reduced. Electrophoretic pattern of pepsin collagen solubilized fraction of heart and kidney revealed alterations in subunit composition and its types on Dex administration and withdrawal. Thus, administration of Dex induced alterations in the metabolism of collagen and on Dex withdrawal, the system slowly tended to attain normalcy.