Objective To study the effects of positive acceleration (+Gz)on sympathetic nervous activity and plasma catecholamine in miniature pig model with different coronary artery stenosis.Methods Twenty-eight Obama miniature pigs were distributed to mild stenosis (Less than 50%,n =7)group,moderate stenosis (50% ~69%,n =7)group,severe stenosis (more than 70%,n =7)group,and sham-operation control group (n =7).The left anterior descending branch wire cerclage method was adopted for establish animal model of coronary artery steno-sis.We observed the effects of intermittent high +Gz exposure on heart rate and plasma adrenaline (Ad),norepi-nephrine (NE)and dopamine (DA)levels of miniature pigs with different coronary artery stenosis.Results The basal heart rate of severe stenosis group was significant higher than that in the normal control group and mild stenosis group (P <0.05).The heart rate of each group was significantly increased at immediately and 10 minutes after high+Gz exposure.Compare with control group and mild stenosis group,the heart rate of moderate and severe stenosis group were significantly increased.Furthermore,the duration of heart rate increase fast in severe stenosis group was more than 30 minutes after exposure.The plasma Ad,NE levels of severe stenosis groups were significant higher than the control and mild stenosis group (P <0.01)before exposure.Plasma Ad and NE levels in all groups were signifi-cantly increased at immediately and 10min after exposure(P <0.01).The plasma Ad and NE levels return to normal at 30min after exposure in control and mild stenosis group,and the plasma Ad and NE of severe stenosis group contin-ued more than 30 minutes (P <0.01). Plasma DA of each group was significantly increased at once after +Gz ex-posure and return to normal at 10min after exposure(P <0.05.There was significantly increased plasma DA levels in severe stenosis group than the other group at 10min after exposure(P <0.05).Conclusion +Gz exposure can acti-vate sympathetic nervous system and increase plasma catecholamine (Ad,NE and DA)levels in miniature pig model, and the effects were much stronger in miniature pig with coronary artery stenosis more than 50% .%目的：研究正加速度（＋Gz）对不同程度冠状动脉狭窄小型猪血浆儿茶酚胺水平和交感神经系统活性的影响。方法以巴马小型猪为研究对象，采用左前降支丝线环扎法建立冠脉轻度狭窄（＜50％）、中度狭窄（50％～69％）、重度狭窄组（≥70％）动物模型，分别给予间断高强度＋Gz 暴露，观察各组心率变化以及血浆肾上腺素（Ad）、去甲肾上腺素（NE）、多巴胺（DA）水平变化。结果基础心率重度狭窄组明显高于健康对照组及轻度狭窄组（P ＜0．05），高强度＋Gz 暴露后即刻、10 min 各组心率均显著增快（P ＜0．01），中度狭窄和重度狭窄组心率较健康对照组进一步增快（P ＜0．01），重度狭窄组心率增快持续超过30 min，其余各组心率在＋Gz 暴露后30 min 恢复正常；＋Gz 暴露前，重度狭窄组血浆 Ad、NE 水平明显高于对照组及轻度狭窄组（P ＜0．01），暴露后各组血浆 AD、NE 水平均显著增高（P ＜0．01），轻度、中度狭窄组至暴露后30 min 时恢复正常，重度狭窄组持续超过30 min（P ＜0．01）。暴露后10 min 时中度及重度狭窄组血浆 Ad、NE 水平均较对照组及轻度狭窄组显著增高（P ＜0．01）；＋Gz 暴露前各组 DA 水平差异无统计学意义（P ＞0．05），＋Gz暴露后即刻各组血浆 DA 水平均显著增高（P ＜0．05），其中重度狭窄组 DA 水平显著高于其余各组（P ＜0．05），各组血浆 DA 水平于10 min 时恢复正常。结论＋Gz 暴露可激活冠脉狭窄小型猪交感神经系统、增加血浆儿茶酚胺（Ad、NE、DA）水平，冠脉狭窄≥50％情况下交感神经系统激活更为强烈。
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