$^{14}C$-Palmitoylcarnitine을 생쥐 간 균질물과 반응시킨 결과 1시간 후 33%, 3시간 후에 51%, 6시간 후에 최고 61%의 가수분해를 나타냄으로서, 동물체의 간이 acylcarnitine의 중요한 대사부위 임을 나타내 주었다. $^{14}C$-Palmitoylcarnitine ($^{14}C$-pal. carn)에 의한 $^{14}C$-triacylglycerol ($^{14}C$-TG)의 생합성은 0.1 M tris-HCl buffer, pH 7.4 및 반응온도 $20^{circ}C$에서 각각 최고의 합성율을 나타냈고, ATP, coenzyme A (CoASH), $Ca^{2+}$ 및 $Mg^{2+}$의 cofactor 등은 triacylglycerol 생 합성계에 전혀 영향을 끼치지 않았으며, 이들은 phospholipid 생성계를 활성화시키는 것으로 나타났다. 동일 조건하에서 (U-$^{14}C$)-palmitic acid에 의한 중성지 질의 생합성을 비교하여 본 결과, 반응온도는 $20^{circ}C$가 적정온도였고, 이 반응계는 ATP, CoASH 및 $Mg^{2+}$의 cofactor를 필요로 했는데 반응시간에 따라 차이를 보여주었다. 즉, 30분 반응에서는 cofactor 존재하에서 $^{14}C$-TG 생성이 증가를 보였으나, 3시간 반응에서는 cofactor가 존재하지 않은 대조구보다 $^{14}C$-phospholipids 생성이 증가함을 나타냈다. 간 균질물의 여러 분획에 있어서 $^{14}C$-pal. carn에 의한 $^{14}C$-TG의 생성을 비교해 본 결과, microsomal cytosol 분획에서 가장 높은 triacylglycerol와 diacylglycerol의 생성율을 보였고, 다음이 mitochondria 분획, nuclei와 cell debris 분획 순이었다. 이상의 결과로 보아 palmitoylcarnitine은 microsome에서 cofactor의 도움 없이 직접 acyl group을 이전시켜 중성지질을 생성하는 것을 확인할 수 있었다.
It was confirmed that the important metabolic site of acylcarnitine was liver in mamals from the results of its hydrolysis, in which percent of hydrolysis was 33%, 51 %, and 61% from incubation for 1 h, 3 h, and 6 h, respectively. In the triacylglycerol biosynthesis from (U-$^{14}C$)-palmitolyl-DL-carnitine, the optimum conditions were obtained in 0.1 M tris-HCl buffer, pH 7.4 and $20^{circ}C$ of incubation temperature. The effect of cofactors, such as $Ca^{2+}$, $Mg^{2+}$, ATP, and coenzyme A reduced the formation of triacylglycerol, rather increased the formation of phospholipid. This result showed that triacylglycerol synthesis from palmitolycarnitine did not need any cofactors. The comparison of the triacylglycerol biosynthesis from (U-$^{14}C$)-palmitic acid with that of (U-$^{14}C$)-palmitoyl-DL-carnitine showed the same optimum conditons in pH and incubation temperature. But in cofactors effect, tracylglycerol synthesis from $^{14}C$-palmitic acid was stimulated in the presence of ATP, CoASH, and $Mg^{2+}$ in 30 min incubation when it was compared with or without of cofactors. When the incubation period was prolonged to 3 h, triacylglycerol synthesis was reduced and, on the other hand, phospholipid synthesis was increased significantly more than 6 times. With the results from the different cell fractions, the highest triacylglycerol biosynthesis was prepresented with microsomal cytosol fraction and next was in order of mitochondrial fraction and nuclei cell debris fraction. As conclusion, firstly, it could be postulated that the direct mobilization of acyl group from palmitoylcarnitine to monoacylglycerol and diacylglycerol resulted triacylglycerol synthesis. Secondly, free fatty acid from hydrolysis of palmitoylcarnitine might from acyl CoA in the presence of ATP and CoASH, and continued the sequencial reactions with diacylglycerol and with Iysophospholipid to form the triacylglycerol and phospholipid, respectively.
