TISSUE DISTRIBUTION OF COLD-INDUCED THERMOGENESIS IN CONSCIOUS WARM-ACCLIMATED COLD-ACCLIMATED RATS RE-EVALUATED FROM CHANGES IN TISSUE BLOOD-FLOW - DOMINANT ROLE OF BROWN ADIPOSE-TISSUE IN THE REPLACEMENT OF SHIVERING BY NONSHIVERING THERMOGENESIS
TISSUE DISTRIBUTION OF COLD-INDUCED THERMOGENESIS IN CONSCIOUS WARM-ACCLIMATED COLD-ACCLIMATED RATS RE-EVALUATED FROM CHANGES IN TISSUE BLOOD-FLOW - DOMINANT ROLE OF BROWN ADIPOSE-TISSUE IN THE REPLACEMENT OF SHIVERING BY NONSHIVERING THERMOGENESIS
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DOI：
10.1139/y79-039
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发表时间：
1979-01-01
影响因子：
2.1
通讯作者：
FRYDMAN, ML
中科院分区：
文献类型：
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作者：
FOSTER, DO;FRYDMAN, ML
放射性微球（12-16 .mu）m)用于测量暴露于25、21、6、-6和-19度温度下的清醒、热适应（WA）和冷适应（CA）大鼠的心输出量（CO）、其分数分布和组织血流量。C，目的是评估冷致产热的组织分布。还测量了总耗氧量。25度的CA大鼠。C （CA25）有升高的动静脉分流和其他热应激迹象。CA21被证明是CA组更合适的对照。在两个驯化组中，冷诱导的不参与呼吸运动的总骨骼肌(M)和棕色脂肪组织（BAT）的血流量变化在数量上有很大差异：在WA25和CA21中，流向M的血流量分别为31 （0.24 CO）和27 (0.17 CO) ml/min，流向BAT的血流量分别为2.1和9.7 ml/min；在WA-19和CA-19中，流向M的流量分别为62 （0.32 CO）和35 (0.16 CO) ml/min，流向BAT的流量分别为25和56 ml/min。相比之下，在两个驯化组中，冷暴露对流向其他组织和器官的影响非常相似：例如，在25至-19度之间，流向心脏、胸腔和隔膜的流量增加了约3倍。C，流向皮肤的流量下降了约50%，流向肝、内脏和肾脏的流量很少或根本没有受到寒冷暴露的影响。根据血流的相对变化，估计了不同组织和器官对冷致产热的贡献。显然，BAT是迄今为止冷暴露的CA大鼠产热增加的主要解剖部位，BAT中的非寒战产热大大补充了冷暴露的WA大鼠的寒战产热。
Radioactive microspheres (12-16 .mu.m) were used to measure cardiac output (CO), its fractional distribution and tissue blood flow in conscious, warm-acclimated (WA) or cold-acclimated (CA) white rats exposed to temperatures of 25, 21, 6, -6 and -19.degree. C, the objective being to assess the tissue distribution of cold-induced thermogenesis. Total O2 consumption was also measured. CA rats at 25.degree. C (CA25) had elevated arteriovenous shunting and other signs of heat stress. CA21 proved more suitable controls for the CA group. The cold-induced changes in blood flow to total skeletal muscle not involved in respiratory movements (M) and to the major masses of brown adipose tissue (BAT) were quantitatively very different in the 2 acclimation groups: in WA25 and CA21 flows to M were 31 (0.24 CO) and 27 (0.17 CO) ml/min, respectively, while flows to BAT were 2.1 and 9.7 ml/min; in WA-19 and CA-19 flows to M were 62 (0.32 CO) and 35 (0.16 CO) ml/min, respectively, while flows to BAT were 25 and 56 ml/min. In contrast, the effects of cold exposure on flows to other tissues and organs were remarkably alike in the 2 acclimation groups: e.g., flows to heart, ribcage and diaphragm increased about 3 times between 25 and -19.degree. C, flow to the skin fell about 50% and flows to the hepatosplanchnic region and kidneys were little or not at all affected by cold exposure. Estimates of the contributions of different tissues and organs to cold-induced thermogenesis were made on the basis of the relative changes in blood flow. Apparently BAT is by far the dominant anatomical site of the increased heat production of cold-exposed CA rats and nonshivering thermogenesis in BAT supplements considerably the shivering thermogenesis of cold-exposed WA rats.