Treberg Jason R, Wilson Connie E, Richards Robert C, Ewart K Vanya, Driedzic William R
Ocean Sciences Centre, Memorial University of Newfoundland, St John's Newfoundland, Canada A1C 5S7.
J Exp Biol. 2002 May;205(Pt 10):1419-27. doi: 10.1242/jeb.205.10.1419.
Smelt (Osmerus mordax) were maintained at either ambient water temperature or approximately 5 degrees C and various aspects of their freeze-avoidance response were examined from early winter until early spring. Plasma levels of glycerol, trimethylamine oxide (TMAO) and urea were elevated by December 15 and continued to increase in fish held in ambient conditions. In contrast, fish held under warm conditions exhibited decreased glycerol and urea content in plasma, muscle and liver. Plasma and liver TMAO levels also decreased in these fish while muscle TMAO did not vary from the initial values. The activity of liver enzymes involved with the production of glycerol did not differ significantly between groups and had decreased by the end of the study. Antifreeze protein (AFP) expression increased over the duration of the experiment. In January samples, AFP activity (thermal hysteresis) did not vary significantly between groups but mRNA levels were significantly lower in the smelt held at warm temperatures.
将胡瓜鱼（Osmerus mordax）饲养在环境水温或约5摄氏度的环境中，从初冬到早春期间，对它们的抗冻反应的各个方面进行了研究。到12月15日，甘油、氧化三甲胺（TMAO）和尿素的血浆水平升高，并且在处于环境条件下的鱼中持续增加。相比之下，饲养在温暖条件下的鱼血浆、肌肉和肝脏中的甘油和尿素含量降低。这些鱼的血浆和肝脏TMAO水平也降低，而肌肉TMAO与初始值没有差异。两组之间与甘油生成相关的肝脏酶活性没有显著差异，并且在研究结束时有所下降。在整个实验过程中，抗冻蛋白（AFP）表达增加。在1月份的样本中，两组之间的AFP活性（热滞）没有显著差异，但温暖温度下饲养的胡瓜鱼的mRNA水平显著较低。
