Sepponen K, Ruusunen M, Pakkanen J A, Pösö A R
Department of Basic Veterinary Sciences, P.O. Box 66, University of Helsinki, Helsinki, Finland.
Vet J. 2007 Jul;174(1):122-8. doi: 10.1016/j.tvjl.2006.05.015. Epub 2006 Aug 9.
Lactate, formed mainly in the stomach and small intestines, and short-chain fatty acids (SCFAs) formed in the colon, are ionised and require transporter proteins such as monocarboxylate transporters (MCTs) for absorption. The amounts of MCT1, MCT2, MCT4 and CD147, an ancillary protein for MCT1 and MCT4, were measured by immunoblotting the small intestine and colon of 40 pigs (Landrace, Yorkshire and LandracexYorkshire). MCT1 and MCT4 were found in both small intestine and colon, but MCT2 only in the small intestine. In both small intestine and colon, Yorkshire pigs had more CD147 than Landrace pigs, while no interbreed differences were found in MCT isoforms. Since CD147 is essential for the activity of MCT1 and MCT4, the breed difference suggests that MCT activity is higher in Yorkshire than in Landrace pigs. The absence of MCT2 in the colon suggests that it is mainly a lactate transporter, while MCT1 and MCT4 facilitate the transport of both lactate and SCFA.
乳酸主要在胃和小肠中形成，而短链脂肪酸（SCFAs）在结肠中形成，它们会发生离子化，需要诸如单羧酸转运蛋白（MCTs）等转运蛋白来进行吸收。通过对40头猪（长白猪、约克夏猪以及长白猪与约克夏猪的杂交猪）的小肠和结肠进行免疫印迹分析，测定了MCT1、MCT2、MCT4以及作为MCT1和MCT4辅助蛋白的CD147的含量。在小肠和结肠中均发现了MCT1和MCT4，但MCT2仅存在于小肠中。在小肠和结肠中，约克夏猪的CD147含量均高于长白猪，而在MCT同工型方面未发现品种间差异。由于CD147对MCT1和MCT4的活性至关重要，这种品种差异表明约克夏猪的MCT活性高于长白猪。结肠中不存在MCT2表明它主要是一种乳酸转运蛋白，而MCT1和MCT4则促进乳酸和SCFA的转运。
