不同品种哺乳仔猪精氨酸代谢特性比较研究

Comparative Study on Arginine Metabolism in Different Breeds of Suckling Piglets

我国地方品种猪与外来猪生长速度差异明显。鉴于精氨酸对仔猪生长发育的重要性,本研究选用14日龄哺乳的宁乡猪、湘西黑猪、蓝塘猪、巴马香猪、环江香猪和长白猪各12头,公、母各半,前腔静脉采血,离心分离血清,测定其中游离精氨酸和一氧化氮(NO)的浓度;采集肠道、肌肉、肝脏和肾脏等组织,测定其中的游离精氨酸浓度和NO合成酶(NOS)活性以及N-乙酰谷氨酸合成酶(NAGS,内源性精氨酸合成限速酶)mRNA的绝对表达量。结果表明,长白猪的血清精氨酸浓度显著高于(P<0.05)其他地方品种猪,血清NO浓度高于(P>0.05)其他地方品种猪;各品种猪空肠前段和肝脏中的NOS活性最高,肾脏中的NOS活性最低;长白猪的空肠前段NOS活性仅低于宁乡猪,肝脏NOS活性仅高于环江香猪;在各个组织均检测到NAGS mRNA不同程度的表达,其中肠道和肝脏中的表达水平最高。综上所述,本研究揭示了不同品种哺乳仔猪血清精氨酸和NO浓度、3种主要组织游离精氨酸含量和NOS活性以及12种组织中NAGS基因的表达谱差异,为解释不同品种猪的生长表型差异提供了营养生化基础。

Chinese indigenous pig breeds have significantly different growth rate than foreign breeds. Considering the important role of arginine in growth and development of piglet, twelve 14-day-old suckling piglets （6 males and 6 females） from six breeds, including Ningxiang pig, Xiangxi black pig, Lantang pig, Bama mini-pig, Huanjiang mini-pig and Landrace pig were used, respectively, in the present study. The blood was sampled via precava and the serum was collected after centrifuge in order to analyze the free arginine and nitric oxide （NO）. The tissues of intestine, muscle, liver and kidney were sampled to determine the concentration of free arginine and activity of NO synthetase （NOS）, as well as the mRNA expression level of N-acetylglutamate synthetase （NAGS, rate-limiting enzyme in endogenous arginine synthesis）. The results showed that the serum concentrations of free arginine （P〈0.05） and NO （P〉0.05） in Landrance pig were higher than those in indigenous breeds of pig; the activities of NOS were significantly higher in proximal jejunum than in liver; the NOS activity of proximal jejunum in Landrance pig was lower than that of Ningxiang pig, and of liver were higher than that of Ningxiang pig; NAGS mRNA were ubiquitously distributed in all tissues tested, and centralized in intestine and liver. This study presented the serum concentrations of arginine and NO, free arginine content and NOS activity in three major tissues, and expression profiles of NAGS mRNA in twelve tissues in six breeds of suckling piglets, which provided some nutritional and biochemical knowledge for explaining the various phenotype of different breeds of pig.