Production and disposal of medium-chain fatty acids in children with medium-chain acyl-CoA dehydrogenase deficiency.
The effect of fasting on plasma concentrations of fatty acids has been determined in four children with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. In addition, the in vivo rate of octanoate oxidation was measured, using [1-13C]octanoate. In the three older children (1.5-11.2 years), fasting for up to 18 h stimulated lipolysis, as reflected by the increasing concentration of free fatty acids, but with little rise in concentrations of medium-chain fatty acids, octanoate, decanoate and cis-4-decenoate. In an infant (0.5 year), lipolysis was greater and was accompanied by rising concentrations of medium-chain fatty acids. After 13.5 h there was a rapid increase in the concentration of decanoate and cis-4-decenoate. The calculated in vivo rate of octanoate oxidation was substantial in all patients studied (6.4-13.1 mumol/kg per h) despite very low MCAD activity in vitro. It is concluded that under basal conditions the in vivo oxidation rate of medium-chain fatty acids is near normal in the four children studied with MCAD deficiency.
Heales
S J
SJ
Institute of Child Health, London, UK.
Thompson
G N
GN
Massoud
A F
AF
Rahman
S
S
Halliday
D
D
Leonard
J V
JV
D042964:Acyl-CoA Dehydrogenase; D044944:Acyl-CoA Dehydrogenases / Q000172:deficiency*; D002210:Caprylates / Q000097:blood / Q000378:metabolism; D002648:Child; D003651:Decanoates / Q000097:blood; D005215:Fasting; D005227:Fatty Acids / Q000096:biosynthesis / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006801:Humans; D007223:Infant; D008066:Lipolysis / Q000502:physiology; D008297:Male; D010084:Oxidation-Reduction
D002210:Caprylates; D003651:Decanoates; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D044944:Acyl-CoA Dehydrogenases; D042964:Acyl-CoA Dehydrogenase