Since the very early manned missions in space, a state of anemia associated with reduced erythropoietin levels and reduced plasma volume was disclosed. The reduction in red blood cell mass is driven by a process of selective hemolysis, which has been named neocytolysis. This phenomenon also occurs in people living at a high altitude who descend rapidly to sea level.
View Article and Find Full Text PDFThis article reviews bone adaptation to microgravity, during manned space missions, in humans undergoing Head Down Tilt (HDT) and in Hind-Limb-Suspended Rats. Under microgravity conditions, bone loss occurs in association with hypercalciuria, which in turn modulates Aquaporin 2 (AQP2) excretion in urine, thus avoiding stone forming in space. This report discloses the need to prevent bone loss in order to prepare for long stays at lunar bases or voyages to Mars.
View Article and Find Full Text PDFDuring the last four decades, about 400 people have been in Space, since Yuri Gagarin was sent in 1961 as the first human into Earth orbit. From the very beginning, the circulatory system of astronauts (meaning heart, vascular system, body fluid distribution and balance, and the kidney) was central to the medical concerns of Space physiologists and physicians because of its gravity-dependence. The present manuscript puts emphasize on some key scientists who worked in the field of body fluid regulation and kidney function in the USA, in Russia and in Europe during recent decades.
View Article and Find Full Text PDFPrevious studies reported low urinary albumin excretion in astronauts during space missions, suggesting an effect of microgravity on renal albumin handling. To test this hypothesis, urinary albumin excretion was investigated with use of head-down bed rest at -6 degrees (HDBR), an experimental model of microgravity. Eight healthy young men underwent two phases.
View Article and Find Full Text PDFProteinuria was hypothesized for space mission but research data are missing. Urinary albumin, as index of proteinuria, was analyzed in frozen urine samples collected by astronauts during space missions onboard MIR station and on ground (control). Urinary albumin was measured by a double antibody radioimmunoassay.
View Article and Find Full Text PDFBackground: Physiological changes occur in man during space missions also at the renal level. Proteinuria was hypothesized for space missions but research data are missing.
Methods: Urinary albumin, as an index of proteinuria, and other variables were analyzed in 4 astronauts during space missions onboard the MIR station and on the ground (control).
Background: Many adolescents with anorexia nervosa suffer from severe osteopenia and osteoporosis. We hypothesized that individualized nutrition therapy may improve bone turnover in anorectic patients.
Methods: We studied 19 female patients [mean age, 14.
Background: No data are available about the short- or long-term influences of microgravity in space on the release of gastroenteropancreatic peptides, although these peptides are involved in the regulation of gastrointestinal functions.
Methods: Fasting plasma samples were gained during the EUROMIR-94 mission from a European Space Agency (ESA) astronaut who experienced no signs of space motion sickness in orbit. Plasma concentrations of nine gastroenteropancreatic peptides were measured with sensitive and specific radioimmunoassays.