Busbridge N J, Dascombe M J, Rothwell N J
Dept. of Physiological Sciences, University of Manchester, United Kingdom.
Horm Metab Res. 1993 Apr;25(4):222-7. doi: 10.1055/s-2007-1002081.
Chronic subcutaneous infusion (from osmotic minipumps) of IL-1 beta (1 microgram/d) in male rats over seven days caused transient (1-3 d) increases in body temperature and reductions in body weight gain and food intake. By day 3, when colonic temperature was similar for vehicle and IL-1 infused groups, the acute responses (increases in temperature and VO2) to a maximal dose (1 microgram, sc) of IL-1 beta was almost identical in all animals. In a separate study intraperitoneal infusion of the same dose of IL-1 beta (1 microgram/d) increased the duration of changes in body temperature, weight and food intake, compared to subcutaneous infusion. In further groups of rats, pyrogenic responses to daily injections of IL-1 beta (1 microgram ip) were sustained for the entire 7 d period, but this treatment did not affect body weight. These data demonstrate that tolerance to infusion of IL-1 is not accompanied by reduced maximal responses to acute administration of IL-1, and indicate that more sustained effects of IL-1 are achieved by intraperitoneal rather than subcutaneous infusions, or by repetitive daily injections of the cytokine. These observations indicate that low levels of IL-1 release, maintained over periods of several days could be responsible for changes in body temperature and energy balance during chronic infections or inflammation.
在雄性大鼠中，通过渗透微型泵进行连续7天的白细胞介素-1β（IL-1β，1微克/天）皮下慢性输注，导致体温短暂（1 - 3天）升高，体重增加和食物摄入量减少。到第3天，当给予赋形剂组和输注IL-1组的结肠温度相似时，所有动物对最大剂量（1微克，皮下注射）IL-1β的急性反应（体温和耗氧量增加）几乎相同。在另一项研究中，与皮下输注相比，腹腔内输注相同剂量的IL-1β（1微克/天）增加了体温、体重和食物摄入量变化的持续时间。在另外几组大鼠中，对每日腹腔注射IL-1β（1微克）的致热反应在整个7天期间持续存在，但这种处理不影响体重。这些数据表明，对IL-1输注的耐受性并不伴随着对急性给予IL-1的最大反应降低，并且表明通过腹腔内而非皮下输注，或通过重复每日注射细胞因子可实现IL-1更持久的作用。这些观察结果表明，在慢性感染或炎症期间，持续数天维持的低水平IL-1释放可能是体温和能量平衡变化的原因。
