干旱区生态环境知识资源中心

We examined the capacity for nonshivering thermogenesis in four rodent species residing in the Ordos Plateau of Inner Mongolia. Nonshivering thermogenesis (NST, maximum NST minus resting metabolic rate) was determined for northern three-toed jerboas (Dipus sagitta), midday gerbils (Meriones meridianus), desert hamsters (Phodopus roborovskii), and striped hamsters (Cricetulus barabensis) in spring (May), summer (July), and autumn (October) captured in the Kubuqi desert in 1997. NST was induced by norepinephrine (NE) and measured by using the closed-circuit respirometer at 27 degreesC. Our results showed significant increases from summer to autumn in NST for the four species. NST capacities were 0.52+/-0.27 ml O-2/g(0.73).h (n = 7) in summer and 2.49+/-1.29 (n = 6) in autumn for jerboas, 1.61+/-0.74 (n = 6) in summer and 3.26+/-1.35 (n = 5) in autumn for gerbils, 3.62+/-0.75 (n = 5) in summer and 9.71+/-2.81 (n = 6) in autumn for desert hamsters, and 6.81+/-3.02 (n = 8) in summer and 11.23+/-2.77 (n = 8) in autumn for striped hamsters. These results suggest that small mammals living in the inland and region of Ordos Plateau adapt to their extreme environment physiologically by adjusting their thermogenic capacities to cope with the dramatic seasonal temperature fluctuations.