title: Changes in plasma and buffy layer vitamin C concentrations following major surgery: what do they reflect?
abstract: Plasma and buffy layer vitamin C concentrations have been measured in 19 patients before and following major surgery, and falls of 36% and 43% respectively were recorded on the first post-operative day. However, the change in the buffy layer could not be accounted for by a change in the concentration of vitamin C in platelets, mononuclear cells or polymorphonuclear leucocytes, the cell types which form the buffy layer. The buffy layer change could be explained by a post-surgical increase in the number of polymorphonuclear leucocytes which, when the buffy layer vitamin C is expressed per 10(8) white cells, dilutes the platelet and mononuclear cell contribution to the buffy layer vitamin C concentration. The fall in buffy layer vitamin C does not, therefore, reflect any increased demand for white cell vitamin C in the immediate post-operative period, although the decrease in plasma vitamin C could imply some increased utilisation or redistribution of the non-cellular compartment.
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001205:Ascorbic Acid / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000032:analysis; D009504:Neutrophils / Q000032:analysis; D011184:Postoperative Period
chemical_list: D001205:Ascorbic Acid