Temperature acclimation alters cardiac performance in the lobster Homarus americanus
Temperature acclimation alters cardiac performance in the lobster Homarus americanus
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DOI：
10.1007/s00359-006-0162-1
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发表时间：
2006-12-01
影响因子：
2.1
通讯作者：
Worden, Mary Kate
中科院分区：
文献类型：
--
作者：
Camacho, Joseph;Qadri, Syed Aman;Worden, Mary Kate
美洲龙虾是一种变温动物，生活在海洋环境中，温度变化范围超过 25 摄氏度，并取决于风、潮汐和季节。为了确定心脏功能如何取决于龙虾所适应的水温，我们测量了龙虾体内的心率。适应 20 摄氏度的龙虾的心脏功能上限约为 29 摄氏度，比适应 4 摄氏度的龙虾测量的温度高 5 摄氏度。在 4 至 12 摄氏度的温度范围内，暖驯化还会减慢龙虾的心率。这两种效应在相对较短的暖驯化期（3-14 天）后就很明显。然而，温暖的环境会损害寒冷温度下的心脏功能：暴露于寒冷（< 5 摄氏度）温度几个小时后，温暖环境下的龙虾心率会变得缓慢且心律失常，但冷环境下的龙虾则不会。因此，驯化温度决定了龙虾在野外栖息的 25 摄氏度温度范围的两个极端条件下心脏功能的热极限。这些观察结果表明，通过当时的环境温度调节心脏的热耐受性可以防止由于热应激而导致心力衰竭的可能性。
The American lobster is a poikilotherm that inhabits a marine environment where temperature varies over a 25 degrees C range and depends on the winds, the tides and the seasons. To determine how cardiac performance depends on the water temperature to which the lobsters are acclimated we measured lobster heart rates in vivo. The upper limit for cardiac function in lobsters acclimated to 20 degrees C is approximately 29 degrees C, 5 degrees C warmer than that measured in lobsters acclimated to 4 degrees C. Warm acclimation also slows the lobster heart rate within the temperature range from 4 to 12 degrees C. Both effects are apparent after relatively short periods of warm acclimation (3-14 days). However, warm acclimation impairs cardiac function at cold temperatures: following several hours exposure to frigid (< 5 degrees C) temperatures heart rates become slow and arrhythmic in warm acclimated, but not cold acclimated, lobsters. Thus, acclimation temperature determines the thermal limits for cardiac function at both extremes of the 25 degrees C temperature range lobsters inhabit in the wild. These observations suggest that regulation of cardiac thermal tolerance by the prevailing environmental temperature protects against the possibility of cardiac failure due to thermal stress.