title: Effect of 14 days of bed rest on urine metabolite excretion and plasma enzyme levels.
abstract: After one week of ambulatory baseline measurement, a group of eight men 19-26 years of age remained continuously recumbent for 14 days. Studies were continued for one week following the prolonged recumbency. Urine excretion rates for a number of constituents were determined 2 days before bed rest, on day 14 of bed rest, and day 6 after bed rest. Blood plasma samples were also obtained at these times, and analyzed for several enzymes. On day 14 of bed rest significant increases were observed in urine excretion of total osmotically active substances, magnesium, calcium, phosphate, creatinine, hydroxyproline, and 17-OH corticosteroids. A decrease occurred in urinary glucose excretion. Plasma levels of alkaline phosphatase and LDH-3 were depressed, while plasma GPT was elevated. Many of these changes persisted on day 6 after bed rest, and are interpreted as concomitants of the disuse atrophy of the musculoskeletal system that characterizes prolonged bed rest and weightlessness.
authors.affiliation: White Mountain Research Station, University of California, Berkeley, USA.
authors.forename: N
authors.initials: N
authors.lastname: Pace
authors.forename: B W
authors.initials: BW
authors.lastname: Grunbaum
authors.forename: A M
authors.initials: AM
authors.lastname: Kodama
authors.forename: D F
authors.initials: DF
authors.lastname: Rahlmann
authors.forename: B D
authors.initials: BD
authors.lastname: Newsom
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D001510:Bed Rest; D004573:Electrolytes / Q000378:metabolism* / Q000652:urine; D004798:Enzymes / Q000097:blood / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000097:blood / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000097:blood / Q000378:metabolism; D008297:Male; D009133:Muscular Atrophy / Q000097:blood / Q000378:metabolism* / Q000652:urine; D009584:Nitrogen / Q000378:metabolism / Q000652:urine; D013046:Specific Gravity; D014556:Urine
chemical_list: D004573:Electrolytes; D004798:Enzymes; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D005947:Glucose; D009584:Nitrogen