Viagem espacial: Um desafio sob o ponto de vista da oftalmologia / Space travel: A challenge from the point of view of ophthalmology

RESUMO No final do século vinte, com o surgimento de novas tecnologias e de novos programas espaciais, a medicina aeroespacial ganhou destaque no meio científico uma vez que os estudos relacionados às alterações da fisiologia humana no espaço tornaram-se cada vez mais necessário para a manutenção da saúde de cosmonautas. Os olhos são considerados uma das estruturas mais sensíveis do corpo às alterações vasculares, estruturais e bioquímicas provocadas pela microgravidade e radiação cósmica. Nesse sentido, essa revisão narrativa busca identificar e explicar as principais alterações morfológicas e funcionais que ocorrem no sistema visual em decorrência de missões espaciais.

ABSTRACT At the end of the twentieth century, with the emergence of new technologies and new space programs, aerospace medicine gained prominence in the scientific community since studies related to changes in human physiology in space have become increasingly necessary for the maintenance of cosmonaut health. The eyes are considered one of the most sensitive structures in the body to vascular, structural and biochemical changes caused by microgravity and cosmic radiation. In this sense, this narrative review seeks to identify and explain the main morphological and functional changes that occur in the visual system as a result of space missions.

Collagen Peptides Improve Lymphocyte Distribution in Peripheral Blood and T Lymphocyte Proliferation in Spleen of Mice under the Condition of Simulated Weightlessness / 中国实验血液学杂志

OBJECTIVE@#To investigate whether collagen peptides can improve the immune functions of mice under the condition of simulated weightlessness.@*METHODS@#Mouse tail-suspension model was used to simulate the effects of weightlessness. Tail-suspended mice were intraperitoneally injected with 600 mg collagen peptides per kilogram body weight once a day for 10 days. Then, the mice were killed, and white blood cells were counted and classified. Lymphocyte subsets and T lymphocyte proliferations in spleens were analyzed.@*RESULTS@#Compared with normal control group, total and differential count of leukocytes, lymphocytes, T cells，CD4 and CD8 T cells, B cells and NK cells, and splenic T lymphocyte proliferation all decreased in the weightlessness simulated mice (P＜0.05). Except for NK cells, the above-mentioned parameters were increased after administration of collagen peptides, and some of the parameters were recovered to the levels of normal control mice (P＜0.05).@*CONCLUSION@#Collagen peptides can effectively improve peripheral blood lymphocyte distributions and T lymphocyte proliferations of mice under the condition of simulated weightlessness. This study nay provid the experimental basis for improvement of immune functions of astronauts.

Physiological effects of weightlessness: countermeasure system development for a long-term Chinese manned spaceflight / 医学前沿

The Chinese space station will be built around 2020. As a national space laboratory, it will offer unique opportunities for studying the physiological effects of weightlessness and the efficacy of the countermeasures against such effects. In this paper, we described the development of countermeasure systems in the Chinese space program. To emphasize the need of the Chinese space program to implement its own program for developing countermeasures, we reviewed the literature on the negative physiological effects of weightlessness, the challenges of completing missions, the development of countermeasure devices, the establishment of countermeasure programs, and the efficacy of the countermeasure techniques in American and Russian manned spaceflights. In addition, a brief overview was provided on the Chinese research and development on countermeasures to discuss the current status and goals of the development of countermeasures against physiological problems associated with weightlessness.

Different Types of Low-frequency Electromagnetic Fields Resist Bone Loss Caused by Weightlessness / 中国医学科学院学报

Objective To compare the effects of 50-Hz 0.6-mT low-frequency pulsed electromagnetic fields(PEMFs) and 50-Hz 1.8-mT sinusoidal alternating electromagnetic fields(SEMFs) in preventing bone loss in tail-suspended rats,with an attempt to improve the prevention and treatment of bone loss caused by weightlessness.Methods Tail-suspension rat models were used to simulate microgravity on the ground. Forty rats were randomly divided into four groups[control group,hindlimb-suspended(HLS) group,HLS+PEMFs group,and HLS+SEMFs group],with 10 rats in each group. In the PEMFs treatment group and SEMFs treatment group,the intervention was 90 min per day. Rats were sacrificed after four weeks. Bone mineral density(BMD) of femur and vertebra was measured by dual-energy X-ray absorptiometry and biomechanical strength by AG-IS biomechanical instrument. Serum osteocalcin(OC),tartrate-resistant acid phosphatase 5b(Tracp 5b),parathyroid hormone(PTH),and cyclic adenosine monophosphate(cAMP) were detected by ELISA. The microstructure of bone tissue was observed by Micro-CT and HE staining.Results The BMD of the femur(P=0.000) and vertebrae(P=0.001) in the HLS group was significantly lower than in the control group;the BMD of the femurs(P=0.001) and vertebrae(P=0.039) in the HLS+PEMFs group was significantly higher than in the HLS group;the BMD of the femurs in the HLS+SEMFs group was significantly higher than in the HLS group(P=0.003),but the BMD of the vertebrae showed no significant difference(P=0.130). There was no significant difference in the BMD of the femur(P=0.818) and vertebrae(P=0.614) between the HLS+PEMFs group and the HLS+SEMFs group. The maximum load(P=0.000,P=0.009) and elastic modulus(P=0.015,P=0.009) of the femurs and vertebrae in the HLS group were significantly lower than those in the control group;the maximum load of the femur(P=0.038) and vertebrae(P=0.087) in the HLS+PEMFs group was significantly higher than that in the HLS group,but the elastic modulus was not significantly different from that in the HLS group(P=0.324,P=0.091). The maximum load(P=0.190,P=0.222) and elastic modulus(P=0.512,P=0.437) of femurs and vertebrae in the HLS+SEMFs group were not significantly different from those in the HLS group. There were no significant differences in the maximum load and elastic modulus of femurs(P=0.585,P=0.948) and vertebrae(P=0.668,P=0.349) between the HLS+PEMFs group and the HLS+SEMFs group. The serum OC level in the HLS group was significantly lower than that in the control group(P=0.000),and the OC level in HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.006) were significantly higher than that in the HLS group. The serum Tracp 5b concentration in the HLS group was significantly higher than that in the control group(P=0.011). There was no significant difference between the HLS+PEMFs group(P=0.459) and the HLS+SEMFs group(P=0.469) compared with the control group.Serum Tracp 5b concentrations in the HLS+PEMFs group(P=0.056) and the HLS+SEMFs group(P=0.054) were not significantly different from those in the HLS group. The PTH(P=0.000) and cAMP concentrations(P=0.000) in the HLS group were significantly lower than those in the control group. The PTH(P=0.000,P=0.000) and cAMP concentrations(P=0.000,P=0.000) in the HLS+PEMFs group and the HLS+SEMFs group were significantly higher than in the HLS group. The femoral cancellous bone of the HLS group was very sparse and small compared with the control group. The density and volume of the cancellous bone were similar among the control group,HLS+PEMFs group,and HLS+SEMFs group. Compared with the control group,the HLS group had lower BMD(P=0.000),bone volume (BV)/tissue volume(TV)(P=0.000),number of trabecular bone (Tb.N)(P=0.000),and trabecular thickness(Tb.Th)(P=0.000) and higher trabecular bone dispersion(Tb.Sp)(P=0.000) and bone surface area(BS)/BV(P=0.000). Compared with the HLS group,the HLS+PEMFs group and the HLS+SEMFs group had significantly lower Tb.Sp(P=0.000,P=0.000) and BS/BV(P=0.000,P=0.000) and significantly increased BMD(P=0.000,P=0.000),BV/TV(P=0.001,P=0.004),Tb.Th(P=0.000,P=0.001),and Tb.N(P=0.000,P=0.001). The trabecular thickness significantly differed between the HLS+PEMFs group and the HLS+SEMFs group(P=0.024). The HLS group(P=0.000),HLS+PEMFs group(P=0.000),and HLS+SEMFs group(P=0.000) had the significantly lower osteoblast density on the trabecular bone surface than the control group;however,it was significantly higher in the HLS+SEMFs group(P=0.000) and the HLS+PEMFs group(P=0.000) than in the HLS group. The HLS group had significantly lower density of osteoblasts in the endothelium than the control group(P=0.000);however,the density of osteoblasts was significantly higher in HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.000) than HLS group and was significantly higher in HLS+PEMFs group than in HLS+SEMFs group(P=0.041). Compared with the control group,a large number of fatty cavities were produced in the bone marrow cavity in the HLS group,but the fat globules remarkably decreased in the treatment groups,showing no significant difference from the control group. The number of adipose cells per mm bone marrow in the HLS group was 4 times that of the control group(P=0.000);it was significantly smaller in the HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.000) than in the HLS group,whereas the difference between the HLS+PEMFs group and the HLS+SEMFs group was not statistically significant(P=0.086). Conclusions 50-Hz 0.6-mT PEMFs and 50-Hz 1.8-mT SEMFs can effectively increase bone mineral density and biomechanical values in tail-suspended rats,increase the concentration of bone formation markers in rat blood,activate the cAMP pathway by affecting PTH levels,and thus further increase the content of osteoblasts to prevent the deterioration of bone micro-structure. In particular,PEMFs can prevent the reduction of bone mineral density and maximum load value by about 50% and increase the bone mass of tail-suspended rats by promoting bone formation.

Bone Mineral Density and Osteoporotic Vertebral Fractures in Traditional, Unassisted, Free-Diving Women (Haenyeos)

BACKGROUND: Water pressure and muscle contraction may influence bone mineral density (BMD) in a positive way. However, divers experience weightlessness, which has a negative effect on BMD. The present study investigated BMD difference in normal controls and woman free-divers with vertebral fracture and with no fracture. METHODS: Between January 2010 and December 2014, traditional woman divers (known as Haenyeo in Korean), and non-diving women were investigated. The study population was divided into osteoporotic vertebral fracture and non-fracture groups. The BMD of the lumbar spine and femoral neck was measured. The radiological parameters for global spinal sagittal balance were measured. RESULTS: Thirty free-diving women and thirty-three non-diving women were enrolled in this study. The mean age of the divers was 72.1 ± 4.7 years and that of the controls was 72.7 ± 4.0 years (P = 0.61). There was no statistical difference in BMD between the divers and controls. In divers, cervical lordosis and pelvic tilt were significantly increased in the fracture subgroup compared to the non-fracture subgroup (P = 0.028 and P = 0.008, respectively). Sagittal vertical axis was statistically significantly correlated with cervical lordosis (Spearman's rho R = 0.41, P = 0.03), and pelvic tilt (Spearman's rho R = 0.46, P = 0.01) in divers. CONCLUSION: BMD did not differ significantly between divers and controls during their postmenopausal period. When osteoporotic spinal fractures develop, compensation mechanisms, such as increased cervical lordosis and pelvic tilt, was more evident in traditional woman divers. This may be due to the superior back muscle strength and spinal mobility of this group of women.

Upregulation of miR-223 in the rat liver inhibits proliferation of hepatocytes under simulated microgravity

Long-term spaceflight affects numerous organ systems in the body, including metabolic dysfunction. Recently, ample evidence has demonstrated that the liver is a vulnerable organ during spaceflight. However, the changes in hepatocyte proliferation and cell cycle control under microgravity remain largely unexplored. In the present study, we first confirmed that the serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase, biochemical markers of liver function, were altered in rats under tail suspension (TS) conditions to simulate microgravity, as shown in previous reports. Next, we demonstrated that the cell proliferation activity, determined by Ki67, PCNA and PH3, was significantly decreased at the different TS time points (TS for 14, 28 and 42 days) compared with that in the control group. Consistently, the positive cell cycle regulators Ccna2, Ccnd1, Cdk1, Cdk2 and cyclin D3 were also significantly decreased in the TS groups as shown by quantitative real-time PCR and western blotting analysis. Subsequent analysis revealed that the aberrant hepatocyte proliferation inhibition under simulated microgravity was associated with the upregulation of miR-223 in the liver. We further found that miR-223 inhibited the proliferation of Hepa1-6 cells and identified CDK2 and CUL1 as its direct targets. In addition, the decreased expression of CDK2 and CUL1 was negatively correlated with the level of p27 in vitro and in vivo, which may have been responsible for retarding hepatocyte proliferation. Collectively, these data indicate that upregulation of miR-223 was associated with the inhibition of liver cell growth and reveal the role of miR-223 in rat hepatocyte proliferation disorders and the pathophysiological process under simulated microgravity.

Progress on space oral medicine research under microgravity environment / 华西口腔医学杂志

As an interdisciplinary of stomatology and space medicine, space oral medicine focuses mainly on oral diseases happened under space environment. With the manned space technology stepping into the new era, space oral medicine has been put under the spotlight. This article will review the historical events on this subject, summarize the newly progress especially on craniomaxillofacial bone, tooth-derived stem cell and oral microbiology researches and still put forward future prospect.

Mechanism of cardiac atrophy under weightlessness/simulated weightlessness / 生理学报

Cardiac remodeling is the heart's response to external or internal stimuli. Weightlessness/simulated weightlessness leads to cardiac atrophy and heart function declining. Understanding the mechanism of cardiac atrophy under weightlessness is important to help astronaut recover from unloading-induced cardiovascular changes after spaceflight. Unloading-induced changes of hemodynamics, metabolic demands and neurohumoral regulation contribute to cardiac atrophy and function declining. During this process, Ca(2+)-related signaling, NF-κB signaling, ERK signaling, ubiquitin-proteasome pathway and autophagy are involved in weightlessness-induced cardiac atrophy. This article reviews the underlying mechanism of cardiac atrophy under weightlessness/simulated weightlessness.

Systems specificity in responsiveness to intermittent artificial gravity during simulated microgravity in rats / 生理学报

It has been shown that the minimum gravity exposure requirements vary greatly among different physiological systems. A preliminary comparison between two extremes, vessels vs. bones, shows that not only the mechanostat at the tissue level differs greatly, but also the bone loss during weightlessness may also involve calcium deposition-resorption changes. It seems that the surprising efficacy of intermittent artificial gravity (IAG) is due to the vascular tissues possessing a strong resilience or "memory" function toward restoring their original pre-stress and tensegrity state at the 1 G environment. It appears that the bone tissue is related to a more complex tensegrity paradigm involving both osteoblasts and osteoclasts, and a longer half time for calcium deposition-absorption. Cell-level models (CellML) for calcium dynamics is currently available. We hope that the Physiome Project can use this modeling framework to help interpret the resistance of bones to IAG and to evaluate whether the "intermittent" or "continuous" AG scheme should be adopted eventually for future exploration-class spaceflight.

Effect of Long-Term Antiorthostatic Suspension in a Murine Model of Acute Lung Injury

OBJECTIVES: Antiorthostatic suspension (AOS) is ground-based model of simulated microgravity. There is still no study about the effect of long-term microgravity on the clinical course of acute lung injury. We evaluated the effect of simulated microgravity using AOS in a murine model of acute lung injury by lipopolysaccharide (LPS). METHODS: Thirty BALB/c mice were used. During 4 weeks, mice were equally allocated to control (free movement), restraint (tail suspended, but hindlimbs not unloaded), and AOS group (hindlimb unloaded). After then, mice got intranasal challenge with LPS (20 mg/kg, 50 μL). We measured: weight gain before and after AOS, the number of inflammatory cells and titers of cytokines (interleukin [IL]-1β, IL-6, IL-10, tumor necrosis factor-α, and interferon-γ) in bronchoalveolar lavage (BAL) fluid, titer of myeloperoxidase (MPO) in serum and lung homogenate, and histopathologic examination of lung tissue. RESULTS: AOS group had significant weight loss compared to control and restraint group (P<0.001). AOS group also showed significantly decreased lymphocytes (P=0.023) compared to control group. In AOS group, titer for IL-1β in BAL fluid was significantly lower than restraint group (P=0.049). Titer for serum MPO was significantly decreased in AOS group compared to restraint group (P=0.004). However, there was no significant difference of MPO titers in lung tissue between groups. Histopathologic examination of lung tissue revealed no significant difference in the degree of pulmonary infiltration between restraint and AOS group. CONCLUSION: In spite of modest anti-inflammatory effect, prolonged AOS caused no significant change in LPS-induced pulmonary inflammation.

Use of Parabolic Flight for the Research of Aerospace Biomedicine / 대한평형의학회지

As it is difficult to perform biological study in the actual space, several researchers have tried to develop methods that could 'mimic' microgravity condition on Earth. During the free fall of the aircraft, so-called 'parabolic flight', objects in a plane could experience weightlessness during a short period of time (approximately 20 to 30 seconds). We first reviewed former studies using parabolic flight in a variety of research filed including vestibular, neurologic, cardiovascular, musculoskeletal and immune system. We also investigated the actual conditions of biologic research using parabolic flight in Korea, by performing a questionnaire survey for 19 experts in space biology.

Effect of electroacupuncture at different acupoints on hormones and neurotransmitters of hypotha- lamic-pituitary-adrenal axis in rats under simulated weightlessness / 中国针灸

<p><b>OBJECTIVE</b>To explore the change pattern of hypothalamic-pituitary-adrenal (HPA) axis and related neurotransmitters under simulated weightlessness.</p><p><b>METHODS</b>A total of 40 clean-grade male Wistar rats were randomly divided into a normal group, a tail-suspension group, an electroacupuncture (EA) at Neiguan (PC 6) group, an EA at Sanyinjiao (SP 6) group, 10 rats in each group. Rats in the tail-suspension group, EA at "Neiguan" (PC 6) group and EA at "Sanyinjiao" (SP 6) group were treated with tail suspension to simulate weightlessness effect. Rats in the normal group were treated with normal diet. Rats in the tail-suspension group were treated with tail suspension for 28 d. During the time of tail suspension, rats in the EA at "Neiguan" (PC 6) group were treated with EA at "Neiguan" (PC 6), 30 min per treatment, once every two days for 14 treatments, while rats in the EA at "Sanyinjiao" (SP 6) group were treated with EA at "Sanyinjiao" (SP 6), 30 min per treatment, once every two days for 14 treatments. Samples were all collected after 4 weeks. The contents of corticotropin releasing hormone (CRH) , adrenocorticotropic hormone (ACTH), corticosterone (CORT) in as well as 5-hydroxy tryptamine (5-HT), dopamine (DA), norepinephrine (NE) were measured by using radioimmunoassay.</p><p><b>RESULTS</b>Compared with the normal group, in the tail-suspension group the content of ACTH in pituitary was significantly decreased (P< 0.05), and the content of 5-HT in hypothalamus was significantly decreased (P < 0.01); the content of CRH and 5-HT in hypothalamus was significantly decreased (P < 0.01, P < 0.05) in the EA at "Neiguan" (PC 6) group; the content of CRH and 5-HT in hypothalamus was significantly decreased (P < 0.01), and the content of CORT in serum was significantly decreased (P < 0.05) in the EA at "Sanyinjiao" (SP 6) group. Compared with the tail-suspension group, the content of ACTH in hypothalamus was significantly decreased (P< 0.05) in the EA at "Neiguan" (PC 6) group; the content of CRH, ACTH and CORT was significantly decreased (P < 0.01, P < 0.05) in the EA at "Sanyinjiao" (SP 6) group. Compared with the EA at "Neiguan" (PC 6) group, the content of CORT was decreased (P < 0.05) in the EA at "Sanyinjiao" (SP 6) group.</p><p><b>CONCLUSION</b>EA can regulate the content of 5-HT in hypothalamus in tail-suspension rats, inhibit the hyperactivity of the HPA axis, in which EA at "Sanyinjiao" (SP 6) had more significant effects than "Neiguan" (PC 6), but no obvious effects on NE and DA were observed.</p>

Bone protection effects of a novel Chinese herbal formula, taikong yangxin prescription, in hindlimb unloaded rats against bone deterioration / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the protective effects of a Chinese herbal formula, taikong yangxin prescription (TKYXP) against bone deterioration in a hindlimb unloaded (tail-suspension) rat model.</p><p><b>METHODS</b>Thirty-two male Sprague-Dawley rats were divided into 4 groups: tail-suspension group fed with 2.5 g•kg(-1)•day(-1) of TKYXP extract (high dose), tail-suspension group fed with 1.25 g•kg(-1)•day(-1) (low dose), tail-suspended group treated with water placebo (placebo control group) and non tail-suspended group. The effects of TKYXP on bone were assessed using peripheral quantitative computed tomography (pQCT), microcomputerized tomography (micro-CT) and three-point bending biomechanical test on the femur in vivo.</p><p><b>RESULTS</b>TKYXP had a significant protective effect against bone loss induced by tail-suspension on day 28, as shown in the reduction in bone mineral density (BMD) loss, preservation of bone micro-architecture and biomechanical strength. The administration ofhigh dose TKYXP could significantly reduce the total BMD loss by 4.8% and 8.0% at the femur and tibia regions, respectively, compared with the placebo control group (P<0.01) on day 28. Its bone protective effect on the femur was further substantiated by the increases of the trabecular BMD (by 6.6%), bone volume fraction (by 20.9%), trabecular number (by 9.5%) and thickness (by 11.9%) as compared with the placebo control group.</p><p><b>CONCLUSION</b>TKYXP may protect the bone under weightless influence from gradual structural deterioration in the tail-suspension model.</p>

Effect of aerospace weightlessness on cognitive functions and the relative dialectical analysis of Chinese medicine / 中国中西医结合杂志

Aerospace medicine has paid more and more attention to abnormal changes of physiological functions induced by weightlessness and studies on their prevention during space flight. In this paper, the effect of space weightlessness on cognitive functions was introduced. We tried to analyze the correlation between the cognitive function changes and relevant Chinese medical syndromes, thus providing a potential available way to prevent and treat weightlessness induced cognitive deficit during space flight.

Effect of acupuncture at different time points on kidney function and oxygen free radical metabolism in rats with simulated weightlessness / 中国针灸

<p><b>OBJECTIVE</b>To explore the effects of pre-acupuncture and immediate acupuncture on kidney function and oxygen free radical metabolism in rats with simulated weightlessness.</p><p><b>METHODS</b>Twenty male clean-grade Wister rats were randomly divided into a normal control group, a model group, a pre-acupuncture group and an immediate acupuncture group, 5 rats in each one. The rats in the normal control group did not receive any treatment but free activities for 4 weeks. The rats in the rest groups received 4-week tail suspension to establish the model of simulated weightlessness. One week before the tail suspension, the rats in the pre-acupuncture group were treated with electroacupuncture at "Shenshu" (BL 23), "Pishu" (BL 20) and "Sanyinjiao" (SP 6) for 30 min per treatment, once a day for 7 days. The rats in the immediate acupuncture group received tail suspension and acupuncture at the same time; during the tail suspension, the electroacupuncture was applied at "Shenshu" (BL 23), "Pishu" (BL 20) and "Sanyinjiao" (SP 6) for 30 min per treatment, once every other day for 14 days. The colorimetric method was used to measure the content of blood urea nitrogen (BUN) in serum as well as activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) and content of malonaldehyde (MDA) in renal tissue in each group.</p><p><b>RESULTS</b>Compared with the normal control group, the content of BUN in the model group was increased significantly (P<0.01), the activity of SOD and GSH-PX in nephridial tissue was significantly reduced (both P<0.01), and the content of MDA was increased significantly (P<0.05). Compared with the model group, the content of BUN in the pre-acupuncture group and immediate acupuncture group was significantly reduced (P<0.01, P<0.05), the activity of GSH-PX in the pre-acupuncture group was obviously increased (P<0.05) and the content of MDA in the immediate acupuncture group was increased significantly (P<0.01). Compared with the immediate acupuncture group, the content of MDA in the pre-acupuncture group was lower (P<0.01).</p><p><b>CONCLUSION</b>The pre-acupuncture and immediate acupuncture both have the capacity to improve the kidney function and anti-oxygen free radical injury in rats with simulated weightlessness, however, the capacity to increase the protection ability of the kidney and eliminate free radical in the pre-acupuncture group is superior to that in the immediate acupuncture group, which is likely to be related with improving antioxidant ability of kidney.</p>

Effect of simulated microgravity and its associated mechanism on pulmonary circulation in rats / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the effect of Simulated Microgravity and its Associated Mechanism on Pulmonary Circulation in Rats).</p><p><b>METHODS</b>Rat tail-suspension model was used to simulate the physiological effects of microgravity and changes in pulmonary blood vessel morphology, pulmonary arterial and venous blood pressure, pulmonary vascular resistance, pulmonary vasomotoricity, as well as the regulation of pulmonary circulation by cytokines produced and released by the lung of rats were measured.</p><p><b>RESULTS</b>The walls of pulmonary blood vessels of rats were thickened, and the pulmonary artery was reconstructed with increased pulmonary vascular resistance. The pulmonary blood vessels of rats became more prone to dilation as contractions increased. Rat epithelial Adrenomedulin gene transcription and protein expression were upregulated. The level of basic fibroblast growth Factor of rat was also elevated.</p><p><b>CONCLUSION</b>Findings from the present study on rats revealed that the microgravity can affect pulmonary blood vessel structure, pulmonary arterial pressure, and pulmonary blood vessel self-regulation and cytokine production.</p>

Thermal comfort and thermoregulation in manned space flight / 中国应用生理学杂志

Exposure to thermal environment is one of the main concerns for manned space exploration. By focusing on the works performed on thermoregulation at microgravity or simulated microgravity, we endeavored to review the investigation on space thermal environmental physiology. First of all, the application of medical requirements for the crew module design from normal thermal comfort to accidental thermal emergencies in a space craft will be addressed. Then, alterations in the autonomic and behavioral temperature regulation caused by the effect of weightlessness both in space flight and its simulation on the ground are also discussed. Furthermore, countermeasures like exercise training, simulated natural ventilation, encouraged drink, etc., in the protection of thermoregulation during space flight is presented. Finally, the challenge of space thermal environment physiology faced in the future is figured out.

Microgravity-induced cardiovascular deconditioning: mechanisms and countermeasures / 中国应用生理学杂志

It has been demonstrated that individuals exposed to actual or simulated microgravity often experience cardiovascular dysfunctions when returning to Earth. The underlying mechanisms of orthostatic intolerance and countermeasure treatment are still poorly understood. In this paper, the progress in the mechanism of cardiovascular deconditioning from the view of vascular remodeling, increased venous compliance in the lower limbs, cellular proliferation and differentiation, and cell signaling pathway was reviewed. Meanwhile, an overview of the countermeasures including exercise, lower body negative pressure, thigh cuffs, traditional Chinese herb medicine and artificial gravity was presented.

Mechanism of weightlessness osteoporosis and preventive and therapeutic effect of traditional Chinese medicine / 中国骨伤

Weightlessness environment can lead to the muscle atrophy and body fluid distribution upward,which can cause the bone calcium metabolism disorder and always accompanied by the loss of bone microstructure and increased rate of bone fracture. Under microgravity,the astronauts are much easier to decrease the Ca2+ ion in bone, which can cause serious osteoporosis. However the bone lost is not equilibrium, it is especially serious in the mechanism loading bone and the recovery process is more difficult. These are very different from the osteoporosis in older people and postmenopausal osteoporosis. It is necessary to find an optimal method to due with it. In traditional Chinese medicine theory,the kidney stores "Jing" and dominates the bone, thus a lot of bone related diseases can be treated through the kidney. A lot of clinical practices have also proved that the Chinese herbs used under the guidance of basic Chinese medicine theory are always good at the treatment of common osteoporosis. In simulated weightlessness experiment, people found that the kidney nourishment drugs do can prevent the decrease of BMD. So in this article we want to review the causes of weightlessness and the potentials applications of tradition Chinese medicine in the treatment of weightlessness osteoporosis.