Walton P E, Gopinath R, Etherton T D
Department of Dairy and Animal Science, Pennsylvania State University, University Park 16802.
Proc Soc Exp Biol Med. 1989 Apr;190(4):315-9. doi: 10.3181/00379727-190-42865.
A growth hormone-dependent insulin-like growth factor (IGF) binding protein (IGFBP) purified from porcine serum specifically blocked the acute insulin-like effects of IGF-I on lipogenesis and glucose oxidation in porcine adipose tissue. This inhibition was dose dependent with half-maximal effective concentrations of IGFBP of 530 ng/ml for lipogenesis and 590 ng/ml for glucose oxidation in the presence of 10(-8) M IGF-I. The IGFBP also caused decreased rates of lipogenesis following a 1-hr preincubation of tissue with IGF-I (10(-8) M). The IGFBP had no effect on insulin action on porcine adipose tissue. These findings demonstrate the inhibitory effects of a highly purified porcine serum IGFBP on the biologic effects of IGF-I in vitro, and provide evidence that the growth hormone-dependent IGFBP blocks the acute insulin-like actions of IGF-I in vivo.
从猪血清中纯化出的一种生长激素依赖性胰岛素样生长因子（IGF）结合蛋白（IGFBP），可特异性阻断IGF-I对猪脂肪组织脂肪生成和葡萄糖氧化的急性胰岛素样作用。在存在10^(-8) M IGF-I的情况下，这种抑制作用呈剂量依赖性，IGFBP对脂肪生成的半数有效浓度为530 ng/ml，对葡萄糖氧化的半数有效浓度为590 ng/ml。在用IGF-I（10^(-8) M）对组织进行1小时预孵育后，IGFBP也导致脂肪生成速率降低。IGFBP对胰岛素作用于猪脂肪组织没有影响。这些发现证明了一种高度纯化的猪血清IGFBP在体外对IGF-I生物学效应的抑制作用，并提供了证据表明生长激素依赖性IGFBP在体内阻断了IGF-I的急性胰岛素样作用。
