Objective： To study the changes in cardiopulmonary function induced by mid/long-term simulated microgravity with 6^° head down bed rest （HDBR）, and the effects of Taikong Yangxin Prescription （太空养心方, TYP） as a countermeasure. Methods： Fourteen healthy male volunteers were randomly divided into a control group and a Chinese medicine （CM） group （7 in each group） by a random digital table based on their body weight. Both groups underwent6^° HDBR for 60 days. Subjects in the CM group received daily TYP pills and subjects in the control group received daily placebo pills. Cardiac systolic and pumping functions were measured by echocardiography before HDBR; on days 20, 42, and 57 of HDBR; and on day 3 of recovery after HDBR （R＋3）. Cardiopulmonary functional reserve and exercise capacity were evaluated before HDBR, on day 29, and on day R＋3 by exercise testing. Results： The heart rate （HR） increased gradually during HDBR. The HR was significantly higher on day 57 than before HDBR in the control group （P〈0.05）, but did not increase significantly in the CM group. The stroke volume/stroke volume index, ejection fraction, and left ventricular fractional shortening tended to decrease over time in the control group, but not in the CM group. These parameters were significantly higher in the CM group than in the control group on day 42 （P〈0.05 or P〈0.01）. Exercise testing showed that maximum 02 consumption （VO2max）, metabolic equivalents, relative 02 consumption （VO2）, 02 pulse, and exercise duration were significantly lower on day 29 than before HDBR in the control group, but not in the CM group. Conclusions： Sixty days of 6^° HDBR induced a reduction in cardiac systolic and pumping functions, and reduced cardiopulmonary functional reserve and exercise capacity. Administration of TYP significantly improved cardiac systolic and pumping functions, and maintained cardiopulmonary functional reserve and exercise capacity.
目的拟通过动物模拟失重模型,研究模拟失重条件下心血管调节功能改变发生的分子机制。方法利用基因芯片技术,检测5例模拟失重大鼠和5例对照大鼠心血管中枢组织基因芯片的变化情况,从基因层面上揭示模拟失重心血管功能变化的实质。结果基因芯片结果显示:模拟失重状态导致心血管中枢部位ADP核糖基化因子样2(ADP-ribosylation factor-like2,Arl2)、孕酮和adipoQ受体家族成员Ⅳ(progestin and adipoQ receptor family member Ⅳ,paqr4)、丙酮酸脱氢酶激酶同工酶1(pyruvate dehydrogenasekinase,isozyme1,pdk1);促生长素抑制蛋白(somatostatin,sst)、跨膜蛋白酶(transmembraneprotease、tmprss5)、丝氨酸5(脊突蛋白)serine5(spinesin)发生了改变。结论失重状态下,心血管功能的变化可能与Arl2、Paqr4、Pdk1、Sst、Tmprss5涉及的转导通路的改变有关。
