An enzymatic method for the determination of butyrobetaine via conversion to carnitine after isolation by high performance liquid chromatography.
An improved procedure for the determination of butyrobetaine [4-(N,N,N-trimethylammonio)butanoate] in plasma and tissue is described. Butyrobetaine was isolated by ion-exchange chromatography and high performance liquid chromatography. The isolation procedure was internally standardized with [3H]butyrobetaine. The recovery of butyrobetaine was greater than 90%. Following isolation butyrobetaine was enzymatically converted to carnitine using butyrobetaine hydroxylase and the resulting carnitine was assayed using carnitine acetyltransferase and [14C]acetylcoenzyme A. The conversion of butyrobetaine to carnitine and of carnitine to [14C]acetylcarnitine was greater than 98% as determined by high performance liquid chromatography. Using this method was analysed human sera (healthy controls) and tissues (autopsy) and found the following values: serum, 4.67 nmol/ml; kidney 17.6 nmol/g; liver, 26.5 nmol/g. The serum butyrobetaine values of twins suffering from carnitine deficiency were normal (3.78 and 3.87 nmol/ml), while the carnitine supplementation therapy caused an increase. Animal samples were analyzed and the values were 3-4 times higher than previously reported by others.
Sandor
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Medical Research, Veterans Administration Medical Center, Cleveland, OH 44106.
Minkler
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Ingalls
S T
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Hoppel
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CL
D000818:Animals; D001622:Betaine / Q000031:analogs & derivatives* / Q000032:analysis; D002331:Carnitine / Q000378:metabolism*; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008722:Methods; D051381:Rats; D011919:Rats, Inbred Strains
D001622:Betaine; C002889:gamma-butyrobetaine; D002331:Carnitine