Karila T, Koistinen H, Seppälä M, Koistinen R, Seppälä T
National Public Health Institute, Laboratory of Pharmacology and Toxicology, Helsinki, Finland.
Clin Endocrinol (Oxf). 1998 Oct;49(4):459-63. doi: 10.1046/j.1365-2265.1998.00556.x.
Body builders may use growth hormone (GH) and anabolic steroids to increase fitness and muscle mass. GH increases serum concentrations of IGF-I and IGFBP-3. The combined effects of GH and anabolic androgenic steroids on IGFBP-3 and IGF-I levels are not known under authentic substance-abusing conditions. The aim of this study was to investigate this in substance-abusing power athletes.
Nine healthy, non-obese and non-competing male power athletes, all aggressive substance abusers, used GH and/or anabolic steroids independently of this study. Blood samples were taken both during and between the drug intake. Sixteen substance non-abusing wrestlers served as controls.
Serum IGF-I concentration was measured by radioimmunoassay and the IGFBP-3 concentration was measured by two immunofluorometric assays, one detecting proteolytic fragments of IGFBP-3. The capacity of serum to proteolytically cleave IGFBP-3 was studied by the proteolysis assay.
While growth hormone increased the IGFBP-3 and IGF-I concentrations, anabolic steroids decreased the same. Concomitant use of growth hormone and anabolic steroids decreased the IGFBP-3 concentration in five out of six abuse periods in spite of the fact that the IGF-I concentration remained elevated in four of them. However, in two men who were on low calorie diet both the IGF-I and IGFBP-3 concentrations decreased during combined GH/anabolic steroid abuse. No proteolytic fragmentation of IGFBP-3 was observed.
Massive abuse of anabolic steroids decreases both the basal and GH-stimulated IGFBP-3 concentrations, whereas its effects on serum IGF-I concentration are variable and affected by low calorie diet. This study demonstrates that detection of GH doping by measuring the IGF-I and/or IGFBP-3 levels has notable confounding factors.
健美运动员可能会使用生长激素（GH）和合成代谢类固醇来增强体质和增加肌肉量。GH会提高血清中胰岛素样生长因子-I（IGF-I）和胰岛素样生长因子结合蛋白-3（IGFBP-3）的浓度。在真实的药物滥用情况下，GH与合成代谢雄激素类固醇对IGFBP-3和IGF-I水平的联合作用尚不清楚。本研究的目的是在滥用药物的力量型运动员中对此进行调查。
九名健康、非肥胖且未参赛的男性力量型运动员，均为滥用药物者，独立于本研究使用GH和/或合成代谢类固醇。在服药期间及服药间隔采集血样。16名未滥用药物的摔跤运动员作为对照。
采用放射免疫分析法测定血清IGF-I浓度，采用两种免疫荧光分析法测定IGFBP-3浓度，其中一种可检测IGFBP-3的蛋白水解片段。通过蛋白水解试验研究血清蛋白水解切割IGFBP-3的能力。
生长激素会提高IGFBP-3和IGF-I浓度，而合成代谢类固醇则降低这些浓度。尽管在六个滥用期中有四个时期IGF-I浓度仍保持升高，但同时使用生长激素和合成代谢类固醇会使六个滥用期中的五个时期的IGFBP-3浓度降低。然而，在两名采用低热量饮食的男性中，在联合滥用GH/合成代谢类固醇期间，IGF-I和IGFBP-3浓度均下降。未观察到IGFBP-3的蛋白水解片段化。
大量滥用合成代谢类固醇会降低基础和GH刺激的IGFBP-3浓度，而其对血清IGF-I浓度的影响则各不相同，并受低热量饮食的影响。本研究表明，通过测量IGF-I和/或IGFBP-3水平来检测GH兴奋剂存在显著的混杂因素。
