探討血液急性蛋白Haptoglobin在運動後增加之生理角色與其機制

Abstract

Haptoglobin簡稱為Hp，是一個抗發炎以及抗氧化的分子，主要由肝臟以及肺臟合成，當身體發炎以及遭受感染時血液中Hp會大量上升。Hp在體內最主要的功能為，當在紅血球發生溶血時Hp能和清除多餘的含鐵離子之血色素，避免產生過多的自由基。 在短暫且激烈的運動過後，體內氧化壓力會大量上升，所以我們提出了一個假說: 為了要減少體內氧化壓力的產生，運動後血液中Hp的濃度會提高。二十四隻實驗小鼠分為四個組別，連續被動運動零週、一週、二週和三週。首先我們發現運動後Hp在血液中濃度會上升，並且在運動三週之嗜中性球數目顯著增加(P<0.05)。有趣的是，被認為是Hp主要來源的肝臟，Hp基因表現量無差異，因此推測嗜中性球是運動後血液Hp升高的來源。由於Hp是一個強力的抗氧化物，推測在運動過程中Hp可以減少氧化壓力的產生，扮演著保護身體的角色。

Haptoglobin (Hp), an anti-inflammatory and antioxidant molecule, is primarily synthesized in lung and liver and sharply increases during inflammation or infection. One of the major functions of Hp is to scavenge the free radicals produced from Fe3+-hemoglobin following the hemolysis of red blood cells. Because after a short-term bout of exhaustive exercise is usually associated oxidative stress, we tested a hypothesis that exercise may elevate plasma Hp in order to reduce the resulting oxidative stress. Mice (n=24) were divided into four groups with 0, 1-, 2 and 3- week passive exercise. First, we demonstrated for the first time that plasma Hp increased substantially overtime following the exercise. Next, we showed neutrophil being significantly increased after three-week exercise (p<0.05). Interestingly, the Hp mRNA of liver, a major organ for Hp synthesis, remained unchanged. Thus, the data indicate that exercise may induce the plasma Hp levels by primarily using neutrophils as a source. Because Hp is an extremely potent antioxidant, the present study suggests that elevated Hp may play a potentially protective role to reduce the oxidative stress during the exercise.