Orthostatic intolerance (OI) is a major problem following spaceflight, and, during flight, astronauts also experience sleep restriction. We hypothesized that sleep restriction will compound the risk and severity of OI following simulated microgravity and exaggerate the renal, cardioendocrine, and cardiovascular adaptive responses to it. Nineteen healthy men were equilibrated on a constant diet,...

Microgravity and cosmic rays as found in space are difficult to recreate on earth. However, ground-based models exist to simulate space flight experiments. In the present study, an experimental model was utilized to monitor gene expression changes in fetal skin fibroblasts of murine origin. Cells were continuously subjected for 65 h to a low dose (55 mSv) of ionizing radiation (IR), comprising ...

The gravitational field is an important determinant of cardiovascular function. Exposure to microgravity during spaceflight may lead to a series of maladaptive alterations in the cardiovascular system. The authors have previously demonstrated that microgravity can increase the susceptibility to myocardial ischemia‑reperfusion (IR) injury under simulated microgravity. Although Notch1 signaling pr...

Using the cultured chicken embryonic chondrocytes as a model, the effects of simulated microgravity on the microtubular system of the cellular skeleton, extracellular matrix, alkaline phosphatase activity, intracellular free calcium concentration and mitochondrial ATP synthase activity with its oligomycin inhibition rate were studied with a clinostat. The microtubular content was measured by a ...

An in vitro organotypic culture model is needed to understand the complexities of carcinoma tissue consisting of carcinoma cells, stromal cells, and extracellular matrices. We developed a new in vitro model of carcinoma tissue using a rotary cell culture system with four disposable vessels (RCCS-4D) that provides a simulated microgravity condition. Solid collagen gels containing human pancreati...

Cerebral arterial remodeling is one of the critical factors in the occurrence of postspaceflight orthostatic intolerance. We hypothesize that large-conductance calcium-activated K(+) (BK(Ca)) channels in vascular smooth muscle cells (VSMCs) may play an important role in regulating cerebrovascular adaptation during microgravity exposure. The aim of this work was to investigate whether activation...

Microgravity decreases osteoblastic activity, induces actin microfilament disruption and inhibits the responsiveness of osteoblast to cytokines, but the mechanisms remains enigmatic. The F-actin cytoskeleton has previously been implicated in manifold changes of cell shape, function and signaling observed under microgravity. Here we investigate the involvement of microfilament in mediating the e...

The effect of overexpressing the Indian hedgehog (IHH) gene on the chondrogenic differentiation of rabbit bone marrow-derived mesenchymal stem cells (BMSCs) was investigated in a simulated microgravity environment. An adenovirus plasmid encoding the rabbit IHH gene was constructed in vitro and transfected into rabbit BMSCs. Two large groups were used: conventional cell culture and induction mod...

Long-term spaceflight induces both physiological and psychological changes in astronauts. To understand the neural mechanisms underlying these physiological and psychological changes, it is critical to investigate the effects of microgravity on the functional architecture of the brain. In this study, we used resting-state functional MRI (rs-fMRI) to study whether the functional architecture of ...