Xu De-Li, Liu Xin-Yu, Wang De-Hua
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
Physiol Biochem Zool. 2011 Jan-Feb;84(1):87-98. doi: 10.1086/657687.
Small mammals in the temperate area often face fluctuations in food availability. Changes in food availability may have a great influence on an animals' immunity, which is important to their survival. We tested the hypothesis that cellular and humoral immunity would be suppressed by food restriction and restored to control levels by refeeding in Mongolian gerbils Meriones unguiculatus. Forty adult male gerbils were randomly divided into food-restricted (80% of baseline food intake) and food ad lib. groups. Similarly, another 40 adult male gerbils were also randomly assigned to two groups: a group for which food was restricted for 36 d and then provided ad lib. and a group that was continuously fed ad lib. Half of the gerbils in each group were injected with phytohemagglutinin (PHA) and keyhole limpet hemocyanin solution to assess cellular and humoral immunity, respectively; the others were injected with sterile saline as control groups. Food-restricted gerbils had significantly lower body mass, body fat mass, dry thymus mass, wet and dry spleen mass, and serum leptin levels than those of the controls, whereas refeeding restored these parameters to the controls. Both food restriction and refeeding had no significant effect on PHA response indicative of cellular immunity, immunoglobulin G and immunoglobulin M concentrations, and white blood cells. We also found that food restriction decreased corticosterone levels in food-restricted gerbils, while refeeding increased corticosterone levels in refed gerbils compared with the controls. Our results suggest that cellular and humoral immunity were not affected by food restriction and refeeding in gerbils.
温带地区的小型哺乳动物常常面临食物可获得性的波动。食物可获得性的变化可能会对动物的免疫力产生重大影响，而免疫力对它们的生存至关重要。我们检验了这样一个假设：在长爪沙鼠（Meriones unguiculatus）中，食物限制会抑制细胞免疫和体液免疫，而重新喂食会使它们恢复到对照水平。40只成年雄性沙鼠被随机分为食物限制组（基线食物摄入量的80%）和自由采食组。同样，另外40只成年雄性沙鼠也被随机分为两组：一组先进行36天的食物限制，然后自由采食；另一组持续自由采食。每组一半的沙鼠分别注射植物血凝素（PHA）和钥孔戚血蓝蛋白溶液以评估细胞免疫和体液免疫；其余的注射无菌生理盐水作为对照组。食物限制组的沙鼠体重、体脂肪量、胸腺干重、脾脏湿重和干重以及血清瘦素水平均显著低于对照组，而重新喂食使这些参数恢复到对照组水平。食物限制和重新喂食对指示细胞免疫的PHA反应、免疫球蛋白G和免疫球蛋白M浓度以及白细胞均无显著影响。我们还发现，与对照组相比，食物限制降低了食物限制组沙鼠的皮质酮水平，而重新喂食则增加了重新喂食组沙鼠的皮质酮水平。我们的结果表明，食物限制和重新喂食对沙鼠的细胞免疫和体液免疫没有影响。
