Lin X, Adams S H, Odle J
Division of Nutritional Sciences, University of Illinois, Urbana 61801, USA.
Biochem J. 1996 Aug 15;318 ( Pt 1)(Pt 1):235-40. doi: 10.1042/bj3180235.
An experiment was conducted to explore the nature of the radiolabel distribution in acid-soluble products (ASPs) resulting from the oxidation of [1-14C]C7:0 or C8:0 by isolated piglet hepatocytes. The differences between odd and even chain-length and the impacts of valproate and malonate upon the rate of beta-oxidation and ASP characteristics were tested. A minor amount of fatty acid carboxyl carbon (< or = 10% of organic acids identified by radio-HPLC) accumulated in ketone bodies regardless of chain-length or inhibitor used. In all cases, acetate represented the major reservoir of carboxyl carbon, accounting for 60-70% of radiolabel in identified organic acids. Cells given [1-14C]C7:0 accumulated 85% more carboxyl carbon in Krebs cycle intermediates when compared with C8:0, while accumulation in acetate was unaffected. The results are consistent with the hypothesis that anaplerosis from odd-carbon fatty acids affects the oxidative fate of fatty acid carbon. The piglet appears unique in that non-ketogenic routes of fatty acid carbon flow (i.e. acetogenesis) predominate in the liver of this species.
进行了一项实验,以探究分离的仔猪肝细胞氧化[1-¹⁴C] C7:0或C8:0所产生的酸溶性产物(ASP)中放射性标记分布的性质。测试了奇数和偶数链长之间的差异以及丙戊酸和丙二酸对β-氧化速率和ASP特性的影响。无论链长或使用的抑制剂如何,少量脂肪酸羧基碳(通过放射性高效液相色谱法鉴定的有机酸的≤10%)都会在酮体中积累。在所有情况下,乙酸盐是羧基碳的主要储存库,占已鉴定有机酸中放射性标记的60-70%。与C8:0相比,给予[1-¹⁴C] C7:0的细胞在三羧酸循环中间体中积累的羧基碳多85%,而乙酸盐中的积累不受影响。结果与以下假设一致,即奇数碳脂肪酸的回补反应会影响脂肪酸碳的氧化命运。仔猪似乎很独特,因为在该物种的肝脏中,脂肪酸碳流动的非生酮途径(即产乙酸)占主导地位。