Fatty acid composition of phospholipids and neutral lipids from human diabetic small arteries and veins by a new TLC method.
It has been suggested that lipid peroxidation of polyunsaturated fatty acids (PUFA) may play a role in the pathogenesis of diabetic complications. To test this hypothesis, we aimed to compare PUFA composition of small arteries and veins (< 500 microm diameter) obtained from diabetic or non-diabetic Guadeloupean patients undergoing arterio-venous shunt surgery before renal dialysis. Small forearm subcutaneous vessels were analysed by a new TLC method which involved inclusion of vascular biopies directly in alveoles made in the TLC gel and lyophilization onto the plate. The TLC plate was then chromatographed and lipids were both extracted and eluted during this step. Fatty acid composition of phospholipid and neutral lipid fractions were determined. Similar fatty acid composition was obtained for arteries and veins from diabetic or non-diabetic subjects. In phospholipids from diabetic vessels, major changes consisted of a 20% decrease of arachidonic acid (20:4 n-6), a 40% decrease of its elongation product 22:4 n-6 and 30% increase of 18:2 n-6. In neutral lipids, 20:4 n-6 was also diminished by 60% whereas oleic acid increased by 15%. This loss of arachidonic acid in small diabetic vessels suggests impaired delta6-desaturase forming 20:4 n-6 or alternatively increased peroxide formation, in the vascular wall of small vessels in diabetic patients.
Lecomte
M
M
The Diabetic Microangiopathy Unit, LIPHA-INSERM U352, INSA-Lyon, Villeurbanne, France. lecomte@insa.insa-lyon.fr
Claire
M
M
Deneuville
M
M
Wiernsperger
N
N
D000273:Adipose Tissue / Q000378:metabolism; D000328:Adult; D000368:Aged; D000818:Animals; D001011:Aorta / Q000378:metabolism; D016718:Arachidonic Acid / Q000378:metabolism; D001158:Arteries / Q000378:metabolism; D002855:Chromatography, Thin Layer / Q000379:methods*; D006224:Cricetinae; D003920:Diabetes Mellitus / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry*; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D005260:Female; D006801:Humans; D019787:Linoleic Acid / Q000378:metabolism; D008055:Lipids / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D019301:Oleic Acid / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry*; D014680:Veins / Q000378:metabolism
D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D008055:Lipids; D010743:Phospholipids; C008757:palmitoleic acid; D016718:Arachidonic Acid; D019301:Oleic Acid; D019787:Linoleic Acid