Metabolism of palmitaldehyde in human cardiac muscle

Abstract

Palmitaldehyde-1-14[C] was incubated with homogenates of human heart and the distribution of radioactivity in the nonpolar and polar lipids was determined. Comparisons between the radioactivity in the acyl, alkyl and alk-l-enyl moieties were evaluated. The role of palmitaldehyde-[l-3H]-[l-14C] as a possible precursor of the alk-l-enyl chains was also assessed. A comparison of incorporation into heart lipids was made between labelled palmitate, palmitaldehyde and cetyl alcohol. The following metabolic relationships are suggested from the results: 1. 1. Palmitaldehyde appears to be metabolized by a different route than palmitate and cetyl alcohol.2. 2. Most of the incorporated palmitaldehyde was found in triglycerides indicating that the aldehyde was oxidized prior to incorporation.3. 3. At least two pathways exist for the synthesis of alk-l-enyl ethers from aldehydes. One involves reduction to the alcohol and reaction with acyl-dihydroxyacetone phosphate and the second, prior oxidation to the acid followed by incorporation, presumably through the l-acyl linkage.4. 4. Using the three labelled substrates led to an interrelationship which accounts for all three being incorporated into acyl, alkyl and alk-l-enyl chains.