Yahata T, Furuyama F, Nagashima T, Moriya M, Kikuchi-Utsumi K, Kawada T, Kuroshima A
Department of Physiology, Asahikawa Medical College, Asahikawa 078-8510, Japan.
Am J Physiol. 1999 Aug;277(2):R362-7. doi: 10.1152/ajpregu.1999.277.2.R362.
The responses of inbred heat-tolerant FOK rats to cold were compared with those of Wistar King A/H (WKAH) and Std:Wistar (WSTR) strains. The fall of colonic temperature during cold exposure was unexpectedly smaller in FOK than in other groups, but the onset of shivering was delayed in FOK. Norepinephrine (NE)-induced in vivo oxygen consumption and the mitochondrial uncoupling protein 1 level of brown adipose tissue (BAT) were not different among the groups, but the cold-induced increases in in vivo oxygen consumption as well as plasma glycerol and free fatty acids were higher in FOK than in other groups. In vitro NE-induced oxygen consumption of BAT was less in FOK than WSTR, but not WKAH. The magnitude of the NE-induced increase in blood flow through BAT was higher in FOK than in other groups. These results suggest that FOK paradoxically have a high capacity for nonshivering thermogenesis in spite of their high capacity for heat tolerance, probably due to an increased lipid utilization and improved circulation of BAT.
将近交系耐热FOK大鼠对寒冷的反应与Wistar King A/H（WKAH）和标准Wistar（WSTR）品系的大鼠进行了比较。在冷暴露期间，FOK大鼠结肠温度的下降出乎意料地比其他组小，但FOK大鼠颤抖的开始延迟。去甲肾上腺素（NE）诱导的体内氧消耗以及棕色脂肪组织（BAT）的线粒体解偶联蛋白1水平在各组之间没有差异，但冷诱导的体内氧消耗以及血浆甘油和游离脂肪酸的增加在FOK大鼠中比其他组更高。体外实验中，FOK大鼠BAT的NE诱导氧消耗比WSTR少，但比WKAH多。NE诱导的通过BAT的血流增加幅度在FOK大鼠中比其他组更高。这些结果表明，尽管FOK大鼠具有较高的耐热能力，但它们反常地具有较高的非颤抖性产热能力，这可能是由于脂质利用率增加和BAT循环改善所致。
