title: Disparate hydration of adipose and lean tissue require a new model for body water distribution in man.
abstract: The intra and extracellular fluid spaces in adipose tissue were determined by by 3H2O, 82Br-(minus), and 35SO4= uptake, and by appropriate chemical methods, in surgical biopsy material from 16 patients undergoing elective laparatomy. Total water space for adipose tissue was 14 +/- 1.4%: extracellular component was 11 +/- 1.1% in mesenteric and subcutaneous depots. Use of these adipose tissue hydration constants, combined with measurements of total body water (TBW), extracellular water (ECW), total body potassium, and experimentally derived age-specific constants for lean body potassium content, permits development of a four compartment model for body water which considers intra and extracellular components separately for adipose (AT) and adipose-free (AFM) tissue masses. This model has the form (see journal) where x is the total hydration and y the extracellular hydration of the adipose-free mass. The equations can be solved for the ECW and ICW of the adipose-free mass, defined by its potassium content. In four normal subjects, x was measured as 0.80 +/- 0.032, and y as 0.24 +/- 0.017. Thus, the adipose free mass, compared with adipose tissue, has approximately six times the total water and twice the extracellular water content per unit weight.
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001706:Biopsy; D001826:Body Fluids / Q000378:metabolism*; D001834:Body Water / Q000032:analysis / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism*; D005260:Female; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism*; D008055:Lipids / Q000032:analysis; D008297:Male; D008643:Mesentery; D008722:Methods; D008954:Models, Biological; D009765:Obesity / Q000378:metabolism*; D012867:Skin
chemical_list: D008055:Lipids