雨生红球藻对大鼠运动性心肌损伤的保护作用

目的：研究雨生红球藻对长时间、大强度运动导致的大鼠运动性心肌损伤的保护作用。方法：以大强度耐力训练大鼠为模型，将65只42 d龄雄性SPF级Wistar大鼠随机分为5组：安静组（C组）、运动对照组（M组）、运动+雨生红球藻低剂量组（HM I组）、运动+雨生红球藻中剂量组（HM Ⅱ组）、运动+雨生红球藻高剂量组（HM Ⅲ组），每组12只（剔除不符合实验要求的大鼠5只）。雨生红球藻组剂量分别为0.067，0.133，0.4 g/kg，体积为5 ml/kg，每天灌胃（ig）1次，其他组ig等量生理盐水。游泳训练42 d后，测定血清谷丙转氨酶（ALT）等心肌损伤标志物含量、心肌超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量，血清、心肌内皮素（ET）及降钙素基因相关肽（CGRP）含量等相关生化指标。结果：血清ALT、乳酸脱氢酶（LDH）、肌酸激酶（CK）、a-羟丁酸脱氢酶（a-HBDH）、心肌MDA、血清与心肌ET含量，M组较C组显著升高（P<0.05或P<0.01）。心肌SOD活性、血清与心肌CGRP含量，M组较C组显著降低（P<0.05）。血清ALT （P<0.01）、LDH （P<0.01）、CK （P<0.05或P<0.01）含量，HM各组较M组均有所降低，组间无差异，且随剂量增加而递减。血清a-HBDH、ET、心肌ET含量，HM各组较M组均有所降低（P<0.05或P<0.01），且组间随剂量增加而递减；HM Ⅲ组较HM I组显著降低（P<0.05）。心肌MDA含量，HM各组较M组均显著降低（P<0.05或P<0.01），且组间随剂量增加而递减；HM Ⅱ、HM Ⅲ低于HM I组（P<0.01）。心肌SOD活性，HM各组较M组均有所升高（P<0.05或P<0.01），且组间随剂量增加而递增；HM Ⅱ、HM Ⅲ高于HM I组（P<0.01）。血清与心肌CGRP含量，HM各组较M组显著升高（P<0.05或P<0.01），且各组组间随剂量增加而递增；HM Ⅲ组较HM I组显著升高（P<0.05）。结论：不同剂量雨生红球藻可有效地清除机体长时间、大强度运动产生的过量自由基；提高机体免疫力，增强血管cNOS活性，保证ET和CGRP浓度的相对平衡，从而阻止心肌脂质过氧化作用和心肌损伤。其中以高剂量组效果为最好。

The protective effects of Haematococcus pluvialis on the exercise-induced myocardial injury in rat

Objective: To study the protective effects of Haematococcus pluvialis (H. pluvialis) on myocardial injury of rats induced by endurance and intensive exercise.Methods: The model was based on intensive endurance training. Sixty-five male aged 42 days Wistar rats were randomly divided into 5 groups:control group (C group), general training group (M group), low dose H. pluvialis + training group (HM I group), middle dose H. Pluvialis + training group (HM Ⅱ group), high dose H. pluvialis + training group (HM Ⅲ group). Each group included 12 rats, and the rats were assigned to go on a 42-day swimming training regime. Professional gavage were taken daily. The rats in HM I, HM Ⅱ and HM Ⅲ group were treated with H. pluvialis at the doses of 0.067,0.133 and 0.4 g/kg by ig at 5 ml/kg and the normal saline were given to other groups. After a 42-day swimming training regime, myocardial injury markers such as serum alanine aminotransferase (ALT), myocardial superoxide dismutase(SOD) and malondialdehyde (MDA) were detected, the biochemical indexes such as serum and myocardial endothelin (ET) and calcitonin gene related peptide (CGRP)were detected.Results: Serum ALT, lactate dehydrogenase(LDH), creatine kinase(CK), a-hydroxybutyrate dehydrogenase(a-HBDH), ET, myocardial MDA and ET in M group were significantly higher than those in C group (P<0.05 or P<0.01). The myocardial SOD activity and the myocardial and serum CGRP in M group were significantly lower than those in C group(P<0.05 or P<0.01). The contents of serum ALT, LDH and CK in HM groups were lower than those in the M group but there was no significant difference between the two groups. Compared with M group, H. pluvialis could decrease the levels of serum a-HBDH, ET and myocardial ET in a dose-dependent manner (P<0.05 or P<0.01). The above mentioned three parameters in HM Ⅲ group were lower than those in HM I group (P<0.05). H. pluvialis could decrease the levels of myocardial MDA and increase the levels of myocardial SOD activity and serum or myocardial CGRP in a dose-dependent manner (P<0.05 or P<0.01).Conclusion: The different doses of H.pluvialis can effectively reduce the free radicals caused by endurance and intensive training and enhance the immune function. Meanwhile H.pluvialis is able to guarantee the relative balance in ET an CGRP`s concentration. Therefore, the myocardial lipid peroxidation and myocardial injury are encumbered. Additionaly, high dose of H. pluvialis is proven to be the most effective.