Li Y, Seifert M F, Ney D M, Grahn M, Grant A L, Allen K G, Watkins B A
Department of Food Science, Lipid Chemistry and Molecular Biology Laboratory, Purdue University, West Lafayette, Indiana 47907, USA.
J Bone Miner Res. 1999 Jul;14(7):1153-62. doi: 10.1359/jbmr.1999.14.7.1153.
A study was designed to examine the effects of dietary conjugated linoleic acid (CLA) on serum concentrations of insulin-like growth factor-I (IGF-I) and IGF binding proteins (IGFBP) and the relationship of these factors to bone metabolism. Weanling male rats were fed AIN-93G diet containing 70 g/kg of added fat for 42 days. Treatments included 0 g/kg or 10 g/kg of CLA and soybean oil (SBO) or menhaden oil + safflower oil (MSO) following a 2 x 2 factorial design. Serum IGFBP was influenced by dietary polyunsaturated fatty acid (PUFA) type ((n-6) and (n-3)) and CLA (p = 0.01 for 38-43 kDa bands corresponding to IGFBP-3). CLA increased IGFBP level in rats fed SBO (p = 0.05) but reduced it in those fed MSO (p = 0.01). Rats fed MSO had the highest serum IGFBP-3 level. Both (n-3) fatty acids and CLA lowered ex vivo prostaglandin E2 production in bone organ culture. In tibia, rats given CLA had reduced mineral apposition rate (3.69 vs. 2.79 microm/day) and bone formation rate (BFR) (0.96 vs. 0.65 microm3/microm2/day); however, the BFR tended to be higher with MSO. Dietary lipid treatments did not affect serum intact osteocalcin or bone mineral content. These results showed that dietary PUFA type and CLA modulate local factors that regulate bone metabolism.
一项研究旨在探讨膳食共轭亚油酸（CLA）对血清胰岛素样生长因子-I（IGF-I）和IGF结合蛋白（IGFBP）浓度的影响，以及这些因素与骨代谢的关系。将断乳雄性大鼠喂食含70 g/kg添加脂肪的AIN-93G饮食42天。按照2×2析因设计，处理包括添加0 g/kg或10 g/kg的CLA以及大豆油（SBO）或鲱鱼油+红花油（MSO）。血清IGFBP受膳食多不饱和脂肪酸（PUFA）类型（（n-6）和（n-3））以及CLA的影响（对应IGFBP-3的38 - 43 kDa条带，p = 0.01）。CLA使喂食SBO的大鼠的IGFBP水平升高（p = 0.05），但使喂食MSO的大鼠的IGFBP水平降低（p = 0.01）。喂食MSO的大鼠血清IGFBP-3水平最高。（n-3）脂肪酸和CLA均降低了骨器官培养物中前列腺素E2的体外生成。在胫骨中，给予CLA的大鼠的矿物质沉积率降低（3.69对2.79微米/天），骨形成率（BFR）降低（0.96对0.65微米³/微米²/天）；然而，MSO组的BFR往往更高。膳食脂质处理不影响血清完整骨钙素或骨矿物质含量。这些结果表明，膳食PUFA类型和CLA调节调节骨代谢的局部因子。
