Mechanisms of ketamine action on lipid metabolism in rats.
OBJECTIVE
This study was conducted to determine the effect of ketamine on metabolic homoeostasis and particularly in lipoprotein lipase (LPL) activity in adipose tissue.


METHODS
Sixty male Wistar rats were divided into six groups of 10 each. Group A served as controls, while Groups B-F received, respectively, ketamine 60, 80, 100, 120 and 140 mg kg(-1) intraperitoneally. The animals were sacrificed 20 min after the administration of ketamine. Insulin concentrations in plasma and total cholesterol, triglyceride, high-density lipoprotein (HDL) and free fatty acid (FFA) concentrations in serum were measured. LPL activity in adipose tissue and medium-chain acyl-CoA dehydrogenase (MCAD) content in muscle were determined.


RESULTS
FFA concentrations in serum significantly increased from the second lowest dose of ketamine. Insulin concentrations in plasma did not exhibit any significant difference between groups. MCAD levels were 0.5-fold more in Group F than in Group A, while there were no significant differences between control group and Groups B-E. Furthermore, high concentrations (120 and 140 mg kg(-1)) of ketamine interfered with in metabolic homoeostasis by significantly reducing LPL activity, thus elevating triglyceride concentrations in serum without affecting cholesterol and HDL metabolism.


CONCLUSIONS
Ketamine induces various metabolic effects due to changes in adipose LPL activity and MCAD levels in muscles. These findings seem to be significant only at high doses.
Saranteas
T
T
University of Athens, Department of Pharmacology, Medical School, Greece. mourior1@otenet.gr
Zotos
N
N
Lolis
E
E
Stranomiti
J
J
Mourouzis
C
C
Chantzi
C
C
Tesseromatis
C
C
D042964:Acyl-CoA Dehydrogenase / Q000187:drug effects; D000273:Adipose Tissue / Q000187:drug effects / Q000201:enzymology; D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002784:Cholesterol / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006706:Homeostasis / Q000187:drug effects; D007274:Injections, Intraperitoneal; D007328:Insulin / Q000097:blood; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D050356:Lipid Metabolism; D008071:Lipoprotein Lipase / Q000187:drug effects; D008075:Lipoproteins, HDL / Q000097:blood / Q000187:drug effects; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000097:blood
D000778:Anesthetics, Dissociative; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D008075:Lipoproteins, HDL; D014280:Triglycerides; D007649:Ketamine; D002784:Cholesterol; D042964:Acyl-CoA Dehydrogenase; D008071:Lipoprotein Lipase