Increased platelet aggregation and fatty acid oxidation in diabetic rats.
The effects of diabetes on fatty acid oxidation in platelets was determined in streptozotocin-induced diabetic rats. In platelets isolated from diabetes, the oxygen consumption which reflects mainly the degree of fatty acid oxidation and ADP- and thrombin-induced aggregation were increased as compared to non-diabetic rat platelets. Carnitine palmitoyltransferase I (CPT I), the rate-limiting enzyme for fatty acid oxidation, in platelets obtained from diabetes showed a higher Vmax for palmitoyl-CoA and an increased I50 (concentration giving 50% inhibition of CPT I activity) for malonyl-CoA inhibition. These changes observed in fatty acid oxidation in platelets derived from diabetes returned to the control levels after insulin therapy. When platelets were stimulated with thrombin, platelet CPT I activity increased over time in both diabetic and non-diabetic rats. From these findings, fatty acid oxidation in platelets, as in the liver, is likely to be regulated by insulin and both increased CPT I activity and decreased sensitivity to malonyl-CoA inhibition are attributable to enhanced platelet fatty acid oxidation in diabetic rats.
Iida
N
N
Department of Emergency and Critical Care Medicine, Kansai Medical University, Osaka, Japan.
Iida
R
R
Takeyama
N
N
Tanaka
T
T
D015117:5,8,11,14-Eicosatetraynoic Acid / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D010974:Platelet Aggregation; D051381:Rats; D017208:Rats, Wistar; D013917:Thrombin / Q000494:pharmacology
D005227:Fatty Acids; D007328:Insulin; D015117:5,8,11,14-Eicosatetraynoic Acid; D000244:Adenosine Diphosphate; D002334:Carnitine O-Palmitoyltransferase; D013917:Thrombin