Insulin restores fatty acid composition earlier in liver microsomes than erythrocyte membranes in streptozotocin-induced diabetic rats.
Alterations of fatty acid composition have been observed in a number of tissues in both experimental and human diabetes. Suppression of delta 6 desaturase in the liver, a key enzyme of fatty acid desaturation, has been reported to be responsible for these phenomena. We measured the fatty acid composition of the liver and the erythrocytes, and examined delta 6 desaturase activities to compare the effect of short-term insulin therapy on the tissues with and without delta 6 desaturase, ie., the liver and the erythrocytes using streptozotocin (STZ)-induced diabetic rats. Linoleic (P < 0.05), palmitic (P < 0.01) and docosahexaenoic (DHA) acid (P < 0.01) were higher and arachidonic (P < 0.01) and oleic acid (P < 0.01) were lower in the liver microsomes of diabetic rats when compared to those in control rats. These alterations were partly reversed with insulin treatment. In the erythrocyte membrane, linoleic (P < 0.01) and stearic acid (P < 0.05) were higher, and palmitic (P < 0.05), palmitoleic (P < 0.01), and arachidonic acid (P < 0.01) were lower in diabetic rats. In contrast to the case of the liver microsomes, however, these alterations were persistently observed after 48 h of insulin treatment. The activities of delta 6 desaturase in diabetic rats were 68% of those of controls (P < 0.05), and increased to 119% of controls after insulin treatment. These results show that insulin restores the fatty acid composition earlier in the liver microsome than in the erythrocyte membrane in STZ-induced diabetic rats. The erythrocyte membrane would not be suitable for the investigation dealing with rapid changes of fatty acid composition.
Shin
C S
CS
Department of Internal Medicine, Seoul National University College of Medicine, South Korea.
Lee
M K
MK
Park
K S
KS
Kim
S Y
SY
Cho
B Y
BY
Lee
H K
HK
Koh
C S
CS
Min
H K
HK
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D007328:Insulin / Q000494:pharmacology*; D050602:Linoleoyl-CoA Desaturase; D008862:Microsomes, Liver / Q000187:drug effects* / Q000378:metabolism; D009994:Osmolar Concentration; D051381:Rats; D017207:Rats, Sprague-Dawley
D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase