J Anim Sci. 2017 Nov;95(11):5020-5029. doi: 10.2527/jas2017.1830.
Activated immune cells become obligate glucose utilizers, and a large i.v. lipopolysaccharide (LPS) dose causes insulin resistance and severe hypoglycemia. Therefore, study objectives were to quantify the amount of glucose needed to maintain euglycemia following an endotoxin challenge as a proxy of leukocyte glucose requirements. Fifteen fasted crossbred gilts (30.3 ± 1.7 kg) were bilaterally jugular catheterized and assigned 1 of 2 i.v. bolus treatments: control (CON; 10 mL sterile saline; = 7) or LPS challenge + euglycemic clamp (LPS-Eu; 055:B5; 5 μg/kg BW; 50% dextrose infusion to maintain euglycemia; = 8). Following administration, blood glucose was determined every 10 min and dextrose infusion rates were adjusted in LPS-Eu pigs to maintain euglycemia for 8 h. Pigs were fasted for 8 h prior to the bolus and remained fasted throughout the challenge. Rectal temperature was increased in LPS-Eu pigs relative to CON pigs (39.8 vs. 38.8°C; < 0.01). Relative to the baseline, CON pigs had 20% decreased blood glucose from 300 to 480 min postbolus ( = 0.01) whereas circulating glucose content in LPS-Eu pigs did not differ ( = 0.96) from prebolus levels. A total of 116 ± 8 g of infused glucose was required to maintain euglycemia in LPS-Eu pigs. Relative to CON pigs, overall plasma insulin, blood urea nitrogen, β-hydroxybutrate, lactate, and LPS-binding protein were increased in LPS-Eu pigs (295, 108, 29, 133, and 13%, respectively; ≤ 0.04) whereas NEFA was decreased (66%; < 0.01). Neutrophils in LPS-Eu pigs were decreased 84% at 120 min postbolus and returned to CON levels by 480 min ( < 0.01). Overall, lymphocytes, monocytes, eosinophils, and basophils were decreased in LPS-Eu pigs relative to CON pigs (75, 87, 70, and 50%, respectively; ≤ 0.05). These alterations in metabolism and the large amount of glucose needed to maintain euglycemia indicate nutrient repartitioning away from growth toward the immune system. Glucose is an important fuel for the immune system, and data from this study established that the glucose requirements of an intensely and acutely activated immune system in growing pigs are approximately 1.1 g/kg BW/h.
激活的免疫细胞成为必需的葡萄糖利用者，大剂量静脉内脂多糖（LPS）会导致胰岛素抵抗和严重的低血糖。因此，研究目的是量化内毒素挑战后维持血糖正常所需的葡萄糖量，作为白细胞葡萄糖需求的替代指标。15 头空腹杂交母猪（30.3±1.7kg）双侧颈静脉置管，并分为 2 种静脉推注治疗之一：对照组（CON；10ml 无菌生理盐水；=7）或 LPS 挑战+血糖正常钳夹（LPS-Eu；055：B5；5μg/kgBW；50%葡萄糖输注以维持血糖正常；=8）。给药后，每隔 10min 测定血糖，调整 LPS-Eu 猪的葡萄糖输注率以维持 8h 血糖正常。在推注前，猪禁食 8h，整个挑战过程中保持禁食。与 CON 组相比，LPS-Eu 组猪的直肠温度升高（39.8 比 38.8°C；<0.01）。与基线相比，CON 组猪从推注后 300 分钟到 480 分钟的血糖降低了 20%（=0.01），而 LPS-Eu 组猪的循环血糖含量与推注前水平无差异（=0.96）。LPS-Eu 猪需要输注 116±8g 葡萄糖才能维持血糖正常。与 CON 组相比，LPS-Eu 组猪的总血浆胰岛素、血尿素氮、β-羟丁酸、乳酸和 LPS 结合蛋白均升高（分别为 295、108、29、133 和 13%；≤0.04），而 NEFA 降低（66%；<0.01）。LPS-Eu 组猪的中性粒细胞在推注后 120 分钟减少 84%，并在 480 分钟时恢复到 CON 水平（<0.01）。总的来说，与 CON 组相比，LPS-Eu 组猪的淋巴细胞、单核细胞、嗜酸性粒细胞和嗜碱性粒细胞减少（分别为 75、87、70 和 50%；≤0.05）。这些代谢变化和维持血糖正常所需的大量葡萄糖表明，营养物质从生长重新分配到免疫系统。葡萄糖是免疫系统的重要燃料，本研究的数据表明，生长猪强烈和急性激活的免疫系统的葡萄糖需求约为 1.1g/kgBW/h。
