Intracranial ethanol and ambient anoxia elicit selection of cooler water by goldfish.
Intracranial ethanol and ambient anoxia elicit selection of cooler water by goldfish.
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颅内乙醇和环境缺氧引起金鱼选择较冷的水。
DOI：
10.1152/ajpregu.1989.256.1.r133
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
O'Connor,CS
中科院分区：
文献类型：
--
作者：
Crawshaw,LI;Wollmuth,LP;O'Connor,CS
金鱼在10 ℃下缺氧5小时，在10 ℃下常氧5小时，或植入颅内显微注射套管。随后在温度梯度下对所有组进行测试。先前缺氧的金鱼在梯度中的前20分钟选择了比相应的常氧对照组（17.5 +/- 0.7摄氏度）更低的温度（12.8 +/- 1.0摄氏度;平均值+/- SE）。颅内微量注射0.0475 ng乙醇的0.2微升0.7%氯化钠导致立即选择低于基线水平8.7 +/- 1.5 ℃的水，而注射0.7%氯化钠的对照动物选择0.9 +/- 1.0 ℃的水。乙醇浓度越高，效果越好。有效部位仅限于视前核室周的前面;注射到其他54个位点没有效果。金鱼通过将乳酸转化为乙醇来耐受缺氧，乙醇通过鳃扩散。由于损失的乙醇不能被氧化代谢，该过程在能量上是低效的。由于乙醇注射的浓度大大低于缺氧金鱼组织中的乙醇浓度，内源性产生的乙醇可能诱导缺氧金鱼选择较冷的水。这种体温调节行为的改变将导致代谢率降低，显著增加缺氧期间的存活时间。
Goldfish were either subjected to anoxia for 5 h at 10 degrees C, normoxia for 5 h at 10 degrees C, or were implanted with an intracranial microinjection cannula. All groups were subsequently tested in a temperature gradient. The previously anoxic goldfish selected cooler temperatures (12.8 +/- 1.0 degrees C; mean +/- SE) than the corresponding normoxic control group (17.5 +/- 0.7 degrees C) for the first 20 min in the gradient. Intracranial microinjections of 0.0475 ng ethanol in 0.2 microliter 0.7% NaCl led to the immediate selection of water 8.7 +/- 1.5 degrees C below that of base-line levels, whereas control animals injected with 0.7% NaCl selected water 0.9 +/- 1.0 degree C cooler. Increased effects were obtained with higher concentrations of ethanol. The effective site was limited to the anterior aspect of the nucleus preopticus periventricularis; injections into 54 other loci were without effect. Goldfish tolerate anoxia by the conversion of lactate to ethanol, which diffuses across the gills. As the lost ethanol cannot be oxidatively metabolized, this process is energetically inefficient. Because the concentration of the ethanol injections was considerably lower than reported ethanol concentrations in the tissues of anoxic goldfish, endogenously produced ethanol may have induced the selection of cooler water by the anoxic goldfish. This alteration in thermoregulatory behavior would lead to a lower metabolic rate, significantly increasing survival time during anoxia.