Effects of acetyl-L-carnitine and oxfenicine on aorta stiffness in diabetic rats.
BACKGROUND
We compared the haemodynamic and metabolic effects of acetyl-L-carnitine (one of the carnitine derivatives) and of oxfenicine (a carnitine palmitoyltransferase-1 inhibitor) in streptozotocin-induced diabetes in male Wistar rats.


METHODS
Diabetes was induced by a single tail vein injection of 55mgkg(-1) streptozotocin. The diabetic animals daily treated with either acetyl-L-carnitine (150mgkg(-1) in drinking water) or oxfenicine (150mgkg(-1) by oral gavage) for 8weeks,were compared with the untreated age-matched diabetic controls. Arterial wave reflection was derived using the impulse response function of the filtered aortic input impedance spectra. Thiobarbituric acid reactive substances (TBARS) measurement was used to estimate malondialdehyde (MDA) content.


RESULTS
Oxfenicine, but not acetyl-L-carnitine, increased total peripheral resistance in diabetes, which paralleled its elevation in plasma levels of free fatty acids. By contrast, acetyl-L-carnitine, but not oxfenicine, resulted in a significant increase in wave transit time and a decrease in wave reflection factor, suggesting that acetyl-L-carnitine may attenuate the diabetes-induced deterioration in systolic loading condition for the left ventricle. This was in parallel with its lowering of MDA/TBARS content in plasma and aortic walls in diabetes. Acetyl-L-carnitine therapy also prevented the diabetes-related cardiac hypertrophy, as evidenced by the reduction in ratio of the left ventricular weight to body weight.


CONCLUSIONS
Acetyl-L-carnitine, but not oxfenicine, attenuates aortic stiffening and cardiac hypertrophy, possibly through its decrease of lipid oxidation-derived MDA/TBARS in the rats with insulin deficiency.
Chang
Kuo-Chu
KC
Department of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan. kcchang1008@ntu.edu.tw
Tseng
Chuen-Den
CD
Lu
Shao-Chun
SC
Liang
Jin-Tung
JT
Wu
Ming-Shiou
MS
Tsai
Ming-Shian
MS
Hsu
Kwan-Lih
KL
D000108:Acetylcarnitine / Q000627:therapeutic use*; D000704:Analysis of Variance; D000818:Animals; D001011:Aorta / Q000187:drug effects*; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors* / Q000627:therapeutic use; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000503:physiopathology; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014803:Vitamin B Complex / Q000627:therapeutic use*
D004791:Enzyme Inhibitors; D014803:Vitamin B Complex; D000108:Acetylcarnitine; D002334:Carnitine O-Palmitoyltransferase