title: Long-term dry immersion: review and prospects.
abstract: Dry immersion, which is a ground-based model of prolonged conditions of microgravity, is widely used in Russia but is less well known elsewhere. Dry immersion involves immersing the subject in thermoneutral water covered with an elastic waterproof fabric. As a result, the immersed subject, who is freely suspended in the water mass, remains dry. For a relatively short duration, the model can faithfully reproduce most physiological effects of actual microgravity, including centralization of body fluids, support unloading, and hypokinesia. Unlike bed rest, dry immersion provides a unique opportunity to study the physiological effects of the lack of a supporting structure for the body (a phenomenon we call 'supportlessness'). In this review, we attempt to provide a detailed description of dry immersion. The main sections of the paper discuss the changes induced by long-term dry immersion in the neuromuscular and sensorimotor systems, fluid-electrolyte regulation, the cardiovascular system, metabolism, blood and immunity, respiration, and thermoregulation. The long-term effects of dry immersion are compared with those of bed rest and actual space flight. The actual and potential uses of dry immersion are discussed in the context of fundamental studies and applications for medical support during space flight and terrestrial health care.
authors.affiliation: CNRS UMR 6214, INSERM U771, Angers Faculty of Medicine, 49045 Angers Cedex, France. nastassia.navasiolava@etud.univ-angers.fr
authors.forename: Nastassia M
authors.initials: NM
authors.lastname: Navasiolava
authors.forename: Marc-Antoine
authors.initials: MA
authors.lastname: Custaud
authors.forename: Elena S
authors.initials: ES
authors.lastname: Tomilovskaya
authors.forename: Irina M
authors.initials: IM
authors.lastname: Larina
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Mano
authors.forename: Guillemette
authors.initials: G
authors.lastname: Gauquelin-Koch
authors.forename: Claude
authors.initials: C
authors.lastname: Gharib
authors.forename: Inesa B
authors.initials: IB
authors.lastname: Kozlovskaya
mesh_terms: D001510:Bed Rest; D018475:Head-Down Tilt / Q000502:physiology; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D007101:Immersion / Q000503:physiopathology; D008954:Models, Biological; D013026:Space Flight; D014893:Weightlessness; D018474:Weightlessness Simulation / Q000266:history / Q000379:methods / Q000639:trends