Theophylline-induced changes in the activity of carnitine palmitoyltransferase in rat cardiac tissues.
This study is conducted to investigate the influence of oral theophylline administration (100 mg/kg bw per day) on the activity of carnitine palmitoyltransferase (CPT) in cardiac tissues of rats for 5-week interval treatments. Results showed significant increase in the activity of CPT was observed in cardiac tissues of theophylline-treated groups as compared to either control or placebo groups. Moreover, the results showed positive correlations between the cardiac concentrations of long-chain acylcarnitine (LC) and the activity of CPT and between plasma concentrations of LC and the cardiac concentrations of LC (P<0.01), respectively. The observed changes in activity of cardiac CPT might be due to the result from theophylline- enhanced decrease the sensitivity of CPT to inhibition by malonyl-CoA and/or from theophylline-enhanced mobilization of lipid from adipose tissues which consequently stimulated an increased carnitine transport into the tissues to form palmitoylcarnitine groups for subsequent beta-oxidation inside the mitochondria. Thus, these accumulations of acylcarnitine groups in mitochondria may increase the catalytic action of CPT.
Alhomida
A S
AS
Department of Biochemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh, Saudi Arabia. alhomida@ksu.edu.sa
D000818:Animals; D002331:Carnitine / Q000378:metabolism; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D006321:Heart / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013806:Theophylline / Q000633:toxicity*
D013806:Theophylline; D002334:Carnitine O-Palmitoyltransferase; D002331:Carnitine