Effects Of Simulated Weightlessness And High+Gx Load On Myocardial Ultrastructure, Plasma Endothelin-1and C-reactive Protein In Rhesus Macaque

Objective: To explore the effects of30days after simulated weightlessness and high+Gx overload on myocardial ultrastructure, plasma endothelin-1and c-reactiveprotein in rhesus macaque, to study simulated weightlessness and overweight on theeffect of cardiovascular. To verify the spaceship emergency return overweightmedical requirements after the long-term rail flight, to do overload medical evaluationwork, to explore the protective measures to reduce the risk factors that affect thehealth of the astronauts, to protect the physical health of astronauts.Methods: Fifteen male rhesus macaques are provided by the experimental AnimalCenter of the China Astronaut Research and Training Center, age4-8years old,weighing7-11kg, body length85-95cm, viruses, bacteria, parasite control should beconsistent with the relevant requirements of the national general level primates, rhesusmacaque must be B virus and tuberculin test negative, in the SPF animal laboratory ofthe Aerospace Engineering and the Institute of Medicine to simulate weightlessnessfor30days. These rhesus macaques are randomly divided into five groups: simulatedweightlessness group (control group, A),+13Gx group (B),+11Gx/270s exposureafter simulated weightlessness group (C),+13Gx/230s exposure after simulatedweightlessness group (D),+15Gx/200s exposure after simulated weightlessnessgroup (E). The animals were sacrificed to extract blood to measure plasmaendothelin-1and c-reactive protein content one day after the end of the centrifuge.The tissues were fixed by glutaraldehyde and made into electron microscopyspecimens to observe thr change of myocardial ultrastructure in rhesus macaque. Results: The content of group C, D and E plasma endothelin-1and C-reactive proteinincrease than group A, there is statistically significant (P <0.05), there is no statisticalsignificance between the group C, D, E. The content of group D plasma endothelin-1and C-reactive protein increase than group B, there is statistically significant (P<0.05). In the electron microscope, group A visible mitochondria bilayer structureclear and mitochondrial cristae clear; part of the mitochondrial bilayer structuredisappeare and the number of mitochondrial cristae reduce in the group B, C, D.group E mitochondrial edema, vacuolar degeneration, sarcomere fracture.Conclusions:(1)+13Gx exposure after simulated weightlessness can causemyocardial minor injuries,+15Gx exposure after simulated weightlessness can causemyocardial serious injury, along with the increase of+Gx load level, the severity ofmyocardial injury increased.(2) The myocardial injury of overweight afterweightlessness is serious than simply overweight.(3) This study can provideexperimental support for overweight endurance studies and scientific and rationalspacecraft orbit segment emergency return overweight medical.