急性冰水应激对犬血清甲状腺激素、NO及Na、K、Cl离子含量的影响

通过测定急性冰水应激时犬血清甲状腺激素、NO及Na、K、Cl离子含量的变化,来评价急性冰水应激对犬体内能量代谢、氧化应激状态及电解质平衡的影响。试验选取8只成年杂种犬,保定躯干浸于冰水混合物中(0~4)℃,使其进行冰水浴30 min。分别于处理前0.5 h(-0.5 h)及处理后0、0.5、1、3、7 h进行桡静脉采血2 mL,分离血清后测定其甲状腺激素(T3、T4)、一氧化氮(NO)及Na^+、K^+、Cl^-的含量。结果表明:与-0.5 h(处理前)相比,处理后各时间点犬血清T3含量无显著变化(P>0.05),与-0.5 h及0、3、7 h相比,血清T4含量在0.5 h时显著降低(P<0.05);血清NO含量在处理后各时间点均显著高于处理前0.5 h(P<0.05),且1、3、7 h显著高于0、0.5 h(P<0.05);与-0.5 h相比,处理后3 h血清Na^+含量显著升高(P<0.05),血清K^+含量处理后0 h显著高于1、3、7 h(P<0.05),血清Cl^-含量处理前后差异不显著(P>0.05)。研究表明,急性短期冰水应激会扰乱机体的能量代谢状态、降低T4含量,同时造成氧化应激损伤、使NO含量大量升高;引起血清Na、K离子平衡紊乱、含量升高,提示临床上人或动物发生冰水应激时应及时纠正机体能量代谢、氧化还原平衡和电解质的紊乱。

Effects of acute ice water immersion on thyroid hormone,NO and Na^+, K^+, Cl^- in dogs

The effects of acute ice water stress on energy metabolism, oxidative stress and electrolyte balance in dogs were evaluated by measuring the changes in serum thyroid hormone, NO and Na, K, Cl ions in them. Eight adult mongrel dogs were immersed in ice-water mixture(0~4)℃ for 30 minutes. Blood samples were collected from the dogs’ radial vein at 0.5 h(-0.5 h) before treatment, and then at 0, 0.5, 1, 3, 7 h after treatment, respectively. Finally, the levels of hyroid hormone(T3,T4), nitric oxide(NO) and Na, K, Cl. In the serum of the blood samples were measured. The results showed that, at each time point after treatment, there was no significant change in the T3 content in canine serum, compared with that at-0.5 h(P>0.05). Compared with those at-0.5 h, 0 h, 3 h and 7 h, the T4 content in serum at 0.5 h decreased significantly(P<0.05). The NO content in serum was significantly higher at each time point after treatment than that at 0.5 h before treatment, and the content at 1, 3, 7 h was significantly higher than that at 0 and 0.5 h(P<0.05). Compared with-0.5 h, the content of Na^+ in serum increased significantly at 3 h after treatment(P<0.05). The level of K^+ in serum was significantly higher at 0 h than that at 1, 3 and 7 h(P<0.05). However, there was no significant difference in the Cl^-content in serum before and after the treatment(P>0.05). In conclusion, acute short-term ice-water stress disturbed the state of energy metabolism, reduced the T4 content in serum, and caused oxidative stress damage, resulting in a large increase in the NO content. The stress disturbed the balance of Na and K ion in serum by increasing their contents. The present study suggested that the energy metabolism, redox balance and electrolyte disorder in body should be corrected when ice-water stress occurs in dogs or human beings.