Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
J Comp Physiol B. 2010 Jan;180(1):141-9. doi: 10.1007/s00360-009-0394-9. Epub 2009 Aug 8.
We assessed the effects of dietary fatty acid composition on sodium-potassium ATPase (Na(+)/K(+)-ATPase) activity and isoform expression in the gills of juvenile fall chinook salmon, Oncorhynchus tshawytscha by supplementing diets with either anchovy oil (AO) or AO blended with canola oil (CO) so that CO comprised 0% (0CO), 11% (11CO), 22% (22CO), 33% (33CO), 43% (43CO), or 54% (54CO) of the measured dietary lipid content. The effects of diet were assessed in freshwater (FW) following 104 days of diet manipulation, in response to 24-h seawater (SW) transfer at this time, and following an additional 35 days of SW acclimation. Gill Na(+)/K(+)-ATPase activity was not significantly affected by diet at any sampling time, and there were no consistent effects of diet on the expression of the Na(+)/K(+)-ATPase alpha1a isoform. As dietary CO increased, Na(+)/K(+)-ATPase alpha1b mRNA decreased in fish held in FW, with the 43CO and 54CO diet groups having significantly lower levels than fish fed the 0CO and 11CO diets. Twenty-four-hour SW challenge did not affect the expression of the Na(+)/K(+)-ATPase alpha1a isoform in any diet group, but this isoform was down-regulated in all diet groups following 35 days of SW acclimation. Na(+)/K(+)-ATPase alpha1b expression levels increased in response to 24-h SW transfer and SW acclimation only in fish fed the 54CO diet. The effects of the two extreme diets (0CO and 54CO) were also assessed at various time points during 104 days of rearing in FW. Na(+)/K(+)-ATPase alpha1b mRNA levels were greater in fish fed diet 0CO versus those fed diet 54CO at all times during the FW culture period. These data demonstrate that dietary fatty acid composition can influence the gill Na(+)/K(+)-ATPase isoform physiology of juvenile fall-run chinook salmon prior to SW transfer.
我们通过在饲料中添加凤尾鱼油 (AO) 或与菜籽油 (CO) 混合的 AO，使 CO 分别占测定饲料脂质含量的 0% (0CO)、11% (11CO)、22% (22CO)、33% (33CO)、43% (43CO) 或 54% (54CO)，评估了饮食中脂肪酸组成对幼龄秋大麻哈鱼鳃中钠钾-ATP 酶 (Na(+)/K(+)-ATPase) 活性和同工型表达的影响。在进行 104 天的饮食处理后，在淡水 (FW) 中评估了饮食的影响，此时进行了 24 小时的海水 (SW) 转移，并在随后的 35 天的 SW 适应期进行了评估。在任何采样时间，饮食都没有显著影响鳃 Na(+)/K(+)-ATP 酶活性，饮食对 Na(+)/K(+)-ATP 酶 alpha1a 同工型的表达也没有一致的影响。随着饮食中 CO 的增加，在 FW 中饲养的鱼类的 Na(+)/K(+)-ATP 酶 alpha1b mRNA 减少，43CO 和 54CO 饮食组的水平明显低于喂食 0CO 和 11CO 饮食组的鱼类。24 小时的 SW 挑战没有影响任何饮食组的 Na(+)/K(+)-ATP 酶 alpha1a 同工型的表达，但在 35 天的 SW 适应期后，所有饮食组的这种同工型都下调。在仅喂食 54CO 饮食的鱼类中，Na(+)/K(+)-ATP 酶 alpha1b 表达水平在 24 小时的 SW 转移和 SW 适应后增加。在 FW 中饲养 104 天的不同时间点还评估了两种极端饮食 (0CO 和 54CO) 的影响。在 FW 培养期间的所有时间点，喂食 0CO 饮食的鱼类的 Na(+)/K(+)-ATP 酶 alpha1b mRNA 水平均高于喂食 54CO 饮食的鱼类。这些数据表明，在进行 SW 转移之前，饮食中的脂肪酸组成可以影响幼龄秋大麻哈鱼鳃中的 Na(+)/K(+)-ATP 酶同工型生理学。
