SHORT-CHAIN FATTY-ACID METABOLISM IN TEMPERATE MARINE HERBIVOROUS FISH
SHORT-CHAIN FATTY-ACID METABOLISM IN TEMPERATE MARINE HERBIVOROUS FISH
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DOI：
10.1007/bf00302552
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发表时间：
1994-10-01
期刊：
影响因子：
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通讯作者：
SLAYTOR, M
中科院分区：
文献类型：
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作者：
CLEMENTS, KD;GLEESON, VP;SLAYTOR, M
在三种含有肠道内共生体的草食性鱼类——鲱鱼Odax cyanomelas (Richardson, 1850) （Odacidae）、鲳鱼O. pullus (Bloch and Schneider, 1801) （Odacidae）和海鲢criinodus lophodon (Gunther, 1859) （Aplodactylidae）的肠道中鉴定和估计了短链脂肪酸（SCFAs）。短链脂肪酸的最高浓度在所有种类的肠后区。青藻总短链脂肪酸的85%在这一区域被发现。短链脂肪酸的分布与微生物呈正相关，说明短链脂肪酸是微生物厌氧代谢的最终产物。3种植物的主要短链脂肪酸均为乙酸，其含量在20 ~ 29 mmol之间。L（-1）在后肠。丙酸盐和丁酸盐的浓度也较低。此外，在酸中发现了戊酸盐。短链脂肪酸含量最高的肠段乙酸：丙酸盐：丁酸盐：戊酸盐的比值为：83:8:9:1；拉氏肠段为64:21:14:1；龙齿肠段为74:17:9:0。食蟹蟹和棘蟹血中乙酸的浓度分别为1.74 +/- 0.17和1.79 +/- 0.20 mmol。分别l(1)。cyanomelas和C. lophodon的主要组织中都存在激活醋酸所需的酶乙酰辅酶a合成酶，这表明这些鱼类能够利用肠道中产生的醋酸。乙酰辅酶a合成酶活性最高，分别为3.55 +/- 0.51和6.48 +/- 3.18 mmol。cyanomelas和C. lophodon在肾脏中分别发现s（-1）和g组织（-1）。分别在大鼠肝脏、心脏、肌肉、肠道和肾脏中检测乙酰辅酶a水解酶活性。青花草和紫叶草。活性最高的是肝脏，分别为91.22 +/- 9.03和57.35 +/- 7.15 nmol。cyanomelas和C. lophodon分别为s(-1) g组织（-1）。cyanomelas和C. lophodon组织中乙酰辅酶a水解酶的存在提出了血液中的一些醋酸可能是由内源性乙酰辅酶a水解产生的可能性。这些结果有力地支持了一种假设，即后肠内共生菌产生的短链脂肪酸被宿主鱼用作血液燃料，用于能量目的或脂质合成。
Short-chain fatty acids (SCFAs) were identified and estimated in the gut of three herbivorous fish containing gut endosymbionts, the herring cale Odax cyanomelas (Richardson, 1850) (Family Odacidae), the butterfish O. pullus (Bloch and Schneider, 1801) (Family Odacidae) and the sea carp Crinodus lophodon (Gunther, 1859) (Family Aplodactylidae). The highest concentrations of short-chain fatty acids were in the posterior region of the intestine in all species. In O. cyanomelas 85% of the total short-chain fatty acids were found in this region. There was a positive correlation between the distribution of short-chain fatty acids and the microorganisms, suggesting that the short-chain fatty acids were end products of microbial anaerobic metabolism. The major short-chain fatty acid in all three species was acetate, the concentration of which ranged from 20 to 29 mmol.l(-1) in the posterior intestine. Lower concentrations of propionate and butyrate were also found. Additionally, valerate was found in the odacids. The ratio of acetate: propionate :butyrate:valerate in the gut section containing the highest concentration of short-chain fatty acids was 83:8:9:1 in O. cyanomelas, 64:21:14:1 in O. pullus and 74: 17:9:0 in C. lophodon. Acetate was present in the blood of O. cynomelas and C. lophodon at concentrations of 1.74 +/- 0.17 and 1.79 +/- 0.20 mmol.l(-1), respectively. The presence of the enzyme necessary to activate acetate, acetyl CoA synthetase, in the major tissues of both O. cyanomelas and C. lophodon indicates that these fishes are able to utilise acetate produced in the gut. The highest activity of acetyl CoA synthetase, 3.55 +/- 0.51 and 6.48 +/- 3.18 mmol.s(-1) g tissue(-1) in O. cyanomelas and C. lophodon, respectively, was found in the kidney. Acetyl CoA hydrolase activity was detected in the liver, heart, muscle, gut and kidney of 0. cyanomelas and C. lophodon. The highest activity was in the liver of both species, 91.22 +/- 9.03 and 57.35 +/- 7.15 nmol.s(-1) g tissue(-1) in O. cyanomelas and C. lophodon, respectively. The presence of acetyl CoA hydrolase in tissues of O. cyanomelas and C. lophodon raises the possibility that some of the acetate in the blood could arise from hydrolysis of endogenously produced acetyl CoA. The results strongly support the hypothesis that short-chain fatty acids produced by endosymbionts in the posterior intestine are used as a blood fuel either for energy purposes or for lipid synthesis by the host fish.