Fatty acid composition in plasma and platelet phospholipid in hypothyroid patients before and after 1-thyroxine substitution.
The relative concentration of fatty acids in plasma and platelet phospholipids (phosphatidylcholine) was determined in 11 patients with overt hypothyroidism (S-TSH greater than 80 mU/l) before and after 1-thyroxine substitution therapy. During therapy, the linoleic (C18:2) acid content decreased (p less than 0.01) whereas longer and more desaturated fatty acids, including arachidonic (C20:4) acid, increased (p less than 0.01) in plasma phospholipids. Also, oleic (C18:1) acid decreased (p less than 0.01) while the major saturated fatty acids, palmitic (C16:0) and stearic (C18:0) acids, were stable. In platelet membrane phospholipids, a similar reciprocal change in the relative content of linoleic (C18:2) and arachidonic (C20:4) acids, respectively, occurred. In plasma, these changes in linoleic and arachidonic acids were found to be inversely correlated (r = 0.56, p less than 0.05). The change in the linoleic acid content in plasma was also correlated to that in platelets (r = 0.64, p less than 0.05). Thus, we have found that thyroid hormones positively influence the conversion of linoleic acid to longer and more polyunsaturated fatty acids in a way that affects fatty acid composition not only in plasma but also in platelet membrane phospholipids.
Valdemarsson
S
S
Department of Internal Medicine, University Hospital Lund, Sweden.
Gustafson
A
A
D000328:Adult; D001792:Blood Platelets; D002462:Cell Membrane / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010713:Phosphatidylcholines / Q000097:blood*; D013974:Thyroxine / Q000627:therapeutic use*
D005227:Fatty Acids; D010713:Phosphatidylcholines; D013974:Thyroxine