关键词: 黑线仓鼠, 体液免疫, 匙孔血蓝蛋白, 静止代谢率, 能量学代价

Abstract: Life history theory predicts that immune function, like other physiological activities such as thermogenesis and reproduction is energetically expensive. However, little experimental evidence for the energy cost to mount an immune response is available, and such costs may be affected by immunological parameters and assays selected. Therefore, the aim of this study was to explore the energetic cost of mounting an immune response in small mammals. We measured body mass and resting metabolic rate (RMR) at days 0 (before injection), and 5 and 10 days post-injection after a keyhole limpet haemocyanin (KLH) antigen challenge in male and female striped hamsters, Cricetulus barabensis. Concentrations of serum anti-IgM and IgG antibodies were measured by an ELISA assay using orbital venous blood samples. The results showed that: (1) Body masses of males were higher than for females, though no significant differences were found between the experimental and control groups by sex and time period after KLH challenge. (2) Concentrations of serum anti-IgM and IgG antibodies were higher in all KLH-challenged groups (i.e. females and males) than those of the controls. (3) RMR did not show apparent differences between control and KLH challenged groups by sex, and before-and-after KLH-challenge or within the different sampling time points (5 and 10 days post KLH injection). These results indicate that a single KLH challenge activated the humoral immunity of striped hamsters, but did not effect changes on body masses or energy expenditure under unlimited food availability. Possible explanations for these findings include that the cost of an enhancement of the humoral immunity may be at the expense of a reduction of another component of the immune system or that striped hamsters can build a humoral response to a mild immunological challenge without simultaneous extra energy cost.

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