Kawasaki Masashi, Miura Yutaka, Funabiki Ryuhei, Yagasaki Kazumi
Department of Applied Biological Science, Tokyo Noko University Fuchu, Tokyo, Japan.
J Nutr Sci Vitaminol (Tokyo). 2010;56(4):247-54. doi: 10.3177/jnsv.56.247.
The effects of simultaneous dietary fish oil ingestion and sulfur amino acid (L-methionine and L-cystine) supplementation on serum lipid concentrations and various parameters related to the lipid metabolism were studied in Donryu rats subcutaneously implanted with an ascites hepatoma cell line, AH109A. A diet containing 10% fish oil was found to reduce serum triglyceride, total cholesterol, (very-low-density lipoprotein plus low-density lipoprotein)-cholesterol, phospholipid and nonesterified fatty acid (NEFA) concentrations in these animals, and dietary supplementation of 1.2% L-methionine and L-cystine also suppressed these serum lipid concentrations. Hepatic fatty acid synthesis and the availability of serum NEFA were decreased, and epididymal adipose tissue lipoprotein lipase (LPL) activity was elevated by dietary fish oil, while LPL activity in various tissues and hepatic fatty acid oxidation were increased by dietary sulfur amino acids, resulting in a reduction in the serum triglyceride concentration by dietary fish oil and sulfur amino acids, respectively. Dietary fish oil suppressed the hepatoma-induced increase in cholesterogenesis in the host liver, and dietary methionine and cystine enhanced bile acid excretion into feces, which were the causes of the hypocholesterolemic effect. In these serum lipid concentrations, there were significant effects of fish oil ingestion and sulfur amino acid supplementation, but no significant interaction between these two factors was seen. These results indicate that dietary fish oil and sulfur amino acid, L-methionine and L-cystine, have hypolipidemic effects in cancer-related hyperlipidemia, and that the effects of these two factors on the decrease in these serum lipid concentrations are additive; these two factors may affect the lipid metabolism via different pathways and mechanisms.
在皮下植入腹水肝癌细胞系AH109A的唐育大鼠中，研究了同时摄入膳食鱼油和补充含硫氨基酸（L-蛋氨酸和L-胱氨酸）对血脂浓度及与脂质代谢相关的各种参数的影响。发现含10%鱼油的饮食可降低这些动物的血清甘油三酯、总胆固醇、（极低密度脂蛋白加低密度脂蛋白）胆固醇、磷脂和非酯化脂肪酸（NEFA）浓度，膳食补充1.2%的L-蛋氨酸和L-胱氨酸也能抑制这些血脂浓度。膳食鱼油可降低肝脏脂肪酸合成及血清NEFA的可用性，附睾脂肪组织脂蛋白脂肪酶（LPL）活性升高，而膳食含硫氨基酸可增加各组织中的LPL活性及肝脏脂肪酸氧化，从而分别导致膳食鱼油和含硫氨基酸使血清甘油三酯浓度降低。膳食鱼油可抑制肝癌诱导的宿主肝脏胆固醇生成增加，膳食蛋氨酸和胱氨酸可增强胆汁酸向粪便中的排泄，这是产生降胆固醇作用的原因。在这些血脂浓度方面，摄入鱼油和补充含硫氨基酸有显著作用，但这两个因素之间未观察到显著的相互作用。这些结果表明，膳食鱼油和含硫氨基酸L-蛋氨酸和L-胱氨酸在癌症相关的高脂血症中具有降血脂作用，且这两个因素对降低这些血脂浓度的作用是相加的；这两个因素可能通过不同途径和机制影响脂质代谢。
