title: Percentage oleic acid is inversely related to percentage arachidonic acid in total lipids of rat serum.
abstract: BACKGROUND
  Since many health effects of oils rich in oleic acid (18:1, n-9) seem to be opposite those of arachidonic acid (20:4, n-6), i.e. concerning cardiovascular risk, we examined whether % 18:1 might be negatively associated with % 20:4.
  
  
  METHODS
  Fatty acid separation by gas chromatography was performed in total serum lipids of 36 male rats. Using bivariate correlations and multiple linear regressions we studied the association between oleic acid and arachidonic acid.
  
  
  RESULTS
  We found an inverse relationship (r = -0.885, p < 0.001; n = 36) between percentages of 18:1 and 20:4 in total lipids of rat serum, persisting when controlling for the other fatty acids measured. In a multiple linear regression model with % 20:4 as the dependent variable and percentages of the other fatty acids entered simultaneously as independents, oleic acid and linoleic acid contributed most to predict % 20:4. Per cent 20:4 correlated negatively (p< 0.01) with a Delta-9 desaturase index, i.e. the (18:1)/(18:0) ratio, and with the (20:4)/(18:2) ratio, estimating desaturases/elongase.
  
  
  CONCLUSIONS
  Percentages of 18:1 and 20:4 seem to be inversely related and desaturase/elongase inhibition could be involved. The results might partly explain positive health effects of foods rich in oleic acid.
authors.affiliation: University of Oslo, Norway. a.t.hostmark@medisin.uio.no
authors.forename: Arne Torbjørn
authors.initials: AT
authors.lastname: Høstmark
authors.forename: Anna
authors.initials: A
authors.lastname: Haug
mesh_terms: D000123:Acetyltransferases / Q000097:blood*; D000704:Analysis of Variance; D000818:Animals; D016718:Arachidonic Acid / Q000097:blood*; D002849:Chromatography, Gas; D044943:Fatty Acid Desaturases / Q000097:blood*; D000081031:Fatty Acid Elongases; D019787:Linoleic Acid / Q000097:blood*; D050356:Lipid Metabolism; D008297:Male; D019301:Oleic Acid / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar; D013230:Stearoyl-CoA Desaturase
chemical_list: D016718:Arachidonic Acid; D019301:Oleic Acid; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C029627:delta-9 fatty acid desaturase; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases