13-Hydroxyoctadecaenoic acid (13-HODE) is a bioactive product of linoleic acid oxidation (LA) that regulates multiple signaling processes <i>in vivo</i>. 13-HODE is also produced when dietary LA is oxidized during food processing. It is not known, however, whether dietary 13-HODE is bioavailable and incorporates into tissues. The present study measured the absorption and disposition of unesterified d4-13-HODE into rat liver, visceral adipose, heart and brain following gavage or intravenous injection (n=3 per group). Mass-spectrometry analysis revealed that d4-13-HODE was absorbed within 20 minutes of gavage, and continued to incorporate into plasma esterified lipid fractions containing lipoproteins throughout the 90-minute monitoring period. Intravenously-injected d4-13-HODE was rapidly taken up from plasma, with a half-life of 58.3 seconds. Analysis of liver, visceral adipose, heart and brain collected at 90 minutes post-administration, revealed that the tracer incorporated into liver, adipose and heart, but not brain. Liver and heart incorporation coefficients were significantly higher for esterified d4-13-HODE (calculated from esterified plasma levels in the gavaged group) compared to unesterified d4-13-HODE provided intravenously (P&lt;0.05), suggesting preferential incorporation of esterified d4-13-HODE into these tissues. Free d4-13-HODE entered adipose tissue at a similar rate to esterified d4-13-HODE (P&gt;0.05). Tissue half-life of d4-13-HODE in visceral adipose, liver, and heart was 0.5, 4.5, and 3.7 days, respectively, which is greater than published values for dietary fatty acids such as eicosapentaenoic acid (4.6 hours in liver and 2.7 hours in heart). This study provides new evidence that dietary 13-HODE is absorbed, and incorporated into peripheral tissues but not the brain. The prolonged effects of dietary 13-HODE exposure on tissue levels and physiology remain to be determined.

Determining the absorption and tissue incorporation kinetics of linoleic acid-derived 13-hydroxyoctadecadienoic acid in rats

ACS Spring Meeting 2021

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