Investigation of the effect of theophylline administration on total, free, short-chain acyl and long-chain acyl carnitine distributions in rat renal tissues.

This study is conducted to investigate the effect of oral theophylline administration on total (TC), free (FC), short-(SC), long-chain acyl (LC), acyl (AC) carnitine distributions as well as the ratio of acyl to free carnitine (AC/FC) in rat renal tissues. Theophylline was administrated at 100 mg kg-1 body weight day-1, and effects were monitored after a treatment period that lasted between 1 week and 5 weeks. The results indicated that theophylline administration leads to significantly higher concentrations of TC, FC, SC, L and AC in renal tissues as compared to those of control and placebo groups (P < 0.001). Moreover, the ratio of AC/FC was significantly increased (P < 0.001) as compared to either control or placebo groups. These changes may result from theophylline-enhanced mobilization of lipids from adipose tissues, which consequently stimulates an increased carnitine transport into the renal tissues to form acylcarnitines for subsequent beta-oxidation inside the renal mitochondria.