Wise T, Klindt J, Buonomo F C
U.S. Department of Agriculture, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska 68933-0166, USA.
Endocrinology. 1995 Aug;136(8):3310-7. doi: 10.1210/endo.136.8.7628365.
As so many variables can affect obesity (age, genetics, health status), new directions, other than reducing or altering diet, are being pursued in controlling obesity in our society. Both dehydroepiandrosterone (DHEA) and GH have reported antiobesity effects; thus, the possible interaction of these hormones was investigated in genetically lean, obese, and meat-type cross-bred male pigs (boars) administered implants that released 0, 2, or 4 mg/day recombinant porcine GH (pGH) for 42 days. Subcutaneous fat was determined by measurement of back fat depth at 2-week intervals, and blood samples were obtained 0, 7, 14, 28, and 42 days post-implant. The weight of perinephrenic fat, an index of abdominal fat, was obtained at death. The obese line had higher DHEA/DHEA sulfate (DHEA-SO4) serum concentrations than the lean and cross-bred boars. Treatment with pGH reduced sc and perinephrenic fat in all lines at both doses (P < 0.01). There was no relationship between day 42 concentrations of DHEA/DHEA-SO4 and indexes of obesity. Concentrations of DHEA/DHEA-SO4 were decreased by pGH treatment (P < 0.01) by days 7-14 in all genetic lines. Concentrations of insulin-like growth factor I, insulin-like growth factor II, and insulin were increased with pGH treatment in all lines (P < 0.01). The a priori hypothesis that increases in these peptides would stimulate gonadal steroidal synthesis (as demonstrated in vitro) and result in elevated DHEA/DHEA-SO4 concentrations and reduced obesity was not supported by pGH-induced decreases in DHEA/DHEA-SO4. Insulin concentrations were elevated 7-14 days postimplant in all lines (P < 0.01), then declined in the later stages of the trial. Insulin concentrations and DHEA/DHEA-SO4 concentrations were inversely related (r = -0.59; P < 0.05); this may indicate that with elevated insulin levels, DHEA/DHEA-SO4 is decreased and has a limited opportunity to affect obesity. Although the administration of DHEA may reduce obesity, the lipolytic action of pGH does not appear to be through increased circulating concentrations of DHEA/DHEA-SO4.
由于诸多变量（年龄、基因、健康状况）都会影响肥胖，因此在我们的社会中，除了减少或改变饮食之外，人们正在探索控制肥胖的新方法。脱氢表雄酮（DHEA）和生长激素（GH）均有抗肥胖作用的报道；因此，研究人员在基因瘦型、肥胖型和肉用型杂交雄性猪（公猪）体内植入能释放0、2或4毫克/天重组猪生长激素（pGH）的植入物，持续42天，以此来研究这些激素之间可能存在的相互作用。每隔两周通过测量背部脂肪深度来测定皮下脂肪，并在植入后0、7、14、28和42天采集血样。在猪死亡时获取肾周脂肪的重量，作为腹部脂肪的一个指标。肥胖品系的公猪血清中脱氢表雄酮/硫酸脱氢表雄酮（DHEA-SO4）的浓度高于瘦型和杂交品系的公猪。两种剂量的pGH处理均使所有品系的皮下脂肪和肾周脂肪减少（P<0.01）。第42天时DHEA/DHEA-SO4的浓度与肥胖指标之间没有关联。在所有基因品系中，pGH处理使DHEA/DHEA-SO4的浓度在第7至14天时降低（P<0.01）。所有品系中，pGH处理均使胰岛素样生长因子I、胰岛素样生长因子II和胰岛素的浓度升高（P<0.01）。之前的假设认为，这些肽的增加会刺激性腺甾体合成（如体外实验所示），从而导致DHEA/DHEA-SO4浓度升高以及肥胖减轻，但pGH导致DHEA/DHEA-SO4降低，这一假设未得到支持。所有品系在植入后7至14天胰岛素浓度升高（P<0.01），然后在试验后期下降。胰岛素浓度与DHEA/DHEA-SO4浓度呈负相关（r=-0.59；P<0.05）；这可能表明，随着胰岛素水平升高，DHEA/DHEA-SO4降低，影响肥胖的机会有限。虽然服用DHEA可能会减轻肥胖，但pGH的脂解作用似乎并非通过提高循环中DHEA/DHEA-SO4的浓度来实现。
