Spurlock M E
Purina Mills, Inc., St. Louis, MO 63144, USA.
J Anim Sci. 1997 Jul;75(7):1773-83. doi: 10.2527/1997.7571773x.
Commercially reared food animals encounter serial pathogenic and nonpathogenic immune challenges throughout production. Because of the diversion of nutrients away from growth in support of immune-related processes, immune challenge is considered a major obstacle to animals' achieving their genetic potential for growth or efficiency of gain. Scientists now recognize that many metabolic processes respond directly or indirectly to proinflammatory cytokines. This cytokine-mediated "reprogramming" of metabolism is a homeorhetic mechanism that ensures an adequate supply of nutrients for proliferation of lymphocyte and macrophage populations, antibody production, and hepatic synthesis of acute phase proteins. Proinflammatory cytokines have been linked to altered nutrient uptake and utilization. Anabolic processes are interrupted, and companion catabolic activities are amplified. Furthermore, cytokines may influence prenatal growth and development, and to the extent that postnatal proliferation and differentiation of myogenic and adipogenic cells contribute to postnatal growth, cytokine regulation of these events may ultimately influence growth. The following discussion is an overview of the impact of immune challenge and proinflammatory cytokines on metabolism and growth.
商业化养殖的食用动物在整个生产过程中会遭遇一系列致病性和非致病性免疫挑战。由于营养物质从生长转向支持免疫相关过程，免疫挑战被认为是动物实现其生长遗传潜力或生长效率的主要障碍。科学家们现在认识到，许多代谢过程直接或间接地对促炎细胞因子作出反应。这种由细胞因子介导的代谢“重编程”是一种体内稳态机制，可确保为淋巴细胞和巨噬细胞群体的增殖、抗体产生以及急性期蛋白的肝脏合成提供充足的营养供应。促炎细胞因子与营养物质的摄取和利用改变有关。合成代谢过程被中断，伴随的分解代谢活动则被放大。此外，细胞因子可能影响产前生长和发育，并且就生肌细胞和成脂细胞的产后增殖和分化对产后生长的贡献而言，细胞因子对这些事件的调节最终可能影响生长。以下讨论概述了免疫挑战和促炎细胞因子对代谢和生长的影响。
