Abstract
This study was conducted to evaluate the effect of theophylline administration on plasma levels of total (TC), free (FC), short- (SC), long-chain acyl carnitine (LC) and the ratio of plasma acyl carnitine to free carnitine (AC/FC) in adult male rats. Theophylline was administered at 100 mg kg(-1) bw/day, and effects were monitored after a treatment period that lasted between 1 and 5 weeks. Theophylline feeding significantly lowered plasma levels of TC, FC and LC as compared to those of control and placebo groups (p<0.01). No significant changes were observed in plasma levels of SC. The results also show that theophylline feeding caused variations in the ratio of plasma AC/FC. Significant changes were observed during the first 3 weeks of theophylline treatment followed by a gradual return toward normal levels by the fourth and fifth weeks. Possible mechanisms for the significant changes of plasma levels of L-carnitine in rats are discussed.