Gualillo O, Eiras S, Lago F, Diéguez C, Casanueva F F
Department of Medicine, University of Santiago de Compostela, School of Medicine, Spain.
Life Sci. 2000 Oct 6;67(20):2433-41. doi: 10.1016/s0024-3205(00)00827-4.
Leptin is a pleiotropic hormone that regulates body weight and energy expenditure. Recent findings suggest that leptin may be involved in acute and/or chronic inflammation, however only limited results are available describing the effects of in vivo models of acute inflammation on leptin secretion. The aim of this study was to evaluate serum leptin levels in response to two well-established models of acute inflammation in rats: carrageenan rat paw induced oedema and carrageenan induced pleurisy. Our results clearly show that leptin levels rise in rats in which both oedema and pleurisy were induced. Serum leptin levels in carrageenan induced paw oedema were 3.86+/-0.16 microg/L in comparison to 1.83+/-0.17 microg/L of control animals (p<0.001). A similar result was observed in carrageenan induced pleurisy animals in which leptin levels were 4.87+/-0.27 microg/L in comparison to 2.19+/-0.16 microg/L of control animals (p<0.001). The increase in leptin levels induced following carrageenan-induced pleurisy appears to be dependent on adrenal function and it is markedly blunted in adrenalectomized rats. Leptin levels in carrageenan induced pleurisy, carried out on adrenalectomized rats, were lower than intact inflamed animals, suggesting a possible involvement of endogenous glucocorticoids. In summary the results here presented show that: a) an elevated plasma leptin concentration was induced during experimental models of inflammation b) this increase is mediated to a large extent by glucocorticoids. In conclusion, acute experimental models of inflammation are associated with changes in circulating leptin suggesting a possible involvement of this hormone in the anorexia/cachexia that is frequently associated with inflammatory processes. Furthermore, our data indicate the existence of a feedback loop among glucocorticoids and leptin which might contribute to the immune response to lace the inflammatory process.
瘦素是一种调节体重和能量消耗的多效性激素。最近的研究结果表明，瘦素可能参与急性和/或慢性炎症，然而，描述急性炎症体内模型对瘦素分泌影响的结果有限。本研究的目的是评估大鼠对两种成熟的急性炎症模型（角叉菜胶诱导的大鼠足肿胀和角叉菜胶诱导的胸膜炎）的血清瘦素水平。我们的结果清楚地表明，在诱导了水肿和胸膜炎的大鼠中，瘦素水平升高。角叉菜胶诱导的足肿胀大鼠血清瘦素水平为3.86±0.16微克/升，而对照动物为1.83±0.17微克/升（p<0.001）。在角叉菜胶诱导的胸膜炎动物中也观察到类似结果，其中瘦素水平为4.87±0.27微克/升，而对照动物为2.19±0.16微克/升（p<0.001）。角叉菜胶诱导的胸膜炎后瘦素水平的升高似乎依赖于肾上腺功能，并且在肾上腺切除的大鼠中明显减弱。在肾上腺切除的大鼠中进行的角叉菜胶诱导的胸膜炎中，瘦素水平低于完整的炎症动物，提示内源性糖皮质激素可能参与其中。总之，这里呈现的结果表明：a）在炎症实验模型中诱导血浆瘦素浓度升高；b）这种升高在很大程度上由糖皮质激素介导。总之，急性炎症实验模型与循环瘦素的变化有关，提示该激素可能参与经常与炎症过程相关的厌食/恶病质。此外，我们的数据表明糖皮质激素和瘦素之间存在反馈回路，这可能有助于对炎症过程进行免疫反应。
