title: Effects of head-down tilt on fluid and electrolyte balance.
abstract: The metabolic effects of -5degrees tilt were studied in eight normal individuals. Exposure to tilt for 24 h increased solution excretion and decreased plasma volume. Plasma renin activity and plasma aldosterone levels were not significantly different from supine values during the first 6 h of tilting, but were increased significantly at the end of the 24-h tilt period. Creatinine clearance and potassium balance were not affected by the tilt. These findings indicate that head-down tilt induces a sodium diuresis and stimulation of the renin-angiotensin-aldosterone system.
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood; D001810:Blood Volume; D004573:Electrolytes / Q000097:blood; D006801:Humans; D008297:Male; D011187:Posture; D012083:Renin / Q000097:blood; D012964:Sodium / Q000652:urine; D013997:Time Factors; D014882:Water-Electrolyte Balance; D014893:Weightlessness
chemical_list: D004573:Electrolytes; D000450:Aldosterone; D012964:Sodium; D012083:Renin