Barboza Perry S, Rombach Emmajean P, Blake John E, Nagy John A
Institute of Arctic Biology, Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA.
J Wildl Dis. 2003 Jul;39(3):610-9. doi: 10.7589/0090-3558-39.3.610.
We compared wild muskoxen (Ovibos moschatus) on Banks Island (Northwest Territories, Canada) with captive animals maintained on grass (Bromus sp.) hay and supplemental minerals. We measured copper (Cu) in liver, whole serum, and deproteinated serum (unbound Cu) as well as serum activity of the Cu-enzyme ceruloplasmin. Unbound serum Cu concentrations did not change with season in captive animals (n = 53). Ceruloplasmin activity was similar between seasons in females but elevated in males during breeding in autumn. Increasing concentrations of Cu in whole sera were mainly associated with protein whereas unbound Cu predominated at low concentrations of whole serum Cu. Ceruloplasmin activity and serum Cu concentration were linearly related to liver Cu in female muskoxen. Measures of copper status in females were lower in the wild (n = 19) than in captivity (n = 16): 8 vs. 160 ug Cu.g-1 of whole liver; 0.67 vs. 1.15 microgram unbound Cu.ml-1 whole serum and; 22 vs. 33 IU.l-1 ceruloplasmin activity. Bioavailability of Cu may limit the population on Banks Island especially when density of animals is high. The wide range of hepatic Cu concentrations in muskoxen indicated accumulation of Cu without apparent ill effect in captive animals. Hepatic storage of Cu may allow wild muskoxen to contend with low and fluctuating availability of Cu in small foraging areas at high latitudes.
我们将加拿大西北地区班克斯岛上的野生麝牛（Ovibos moschatus）与以禾本科（Bromus sp.）干草和补充矿物质饲养的圈养动物进行了比较。我们测量了肝脏、全血清和脱蛋白血清（未结合铜）中的铜（Cu）以及铜酶铜蓝蛋白的血清活性。圈养动物（n = 53）的未结合血清铜浓度不随季节变化。雌性动物不同季节的铜蓝蛋白活性相似，但雄性动物在秋季繁殖期间活性升高。全血清中铜浓度的增加主要与蛋白质有关，而在全血清铜浓度较低时，未结合铜占主导。雌性麝牛的铜蓝蛋白活性和血清铜浓度与肝脏铜呈线性相关。野生雌性麝牛（n = 19）的铜状态指标低于圈养雌性麝牛（n = 16）：全肝铜含量分别为8 μg Cu·g-1和160 μg Cu·g-1；全血清未结合铜含量分别为0.67 μg/ml和1.15 μg/ml；铜蓝蛋白活性分别为22 IU·l-1和33 IU·l-1。铜的生物有效性可能限制了班克斯岛上的麝牛种群数量，尤其是在动物密度较高时。麝牛肝脏铜浓度范围很广，表明圈养动物体内铜的积累未产生明显不良影响。肝脏储存铜可能使野生麝牛能够应对高纬度小觅食区铜供应不足且波动的情况。
