Human renal response to meat meal
Hostetter, T.H.
American Journal of Physiology 250(4 Pt 2): F613-F618
1986
ISSN/ISBN: 0002-9513 PMID: 3963200 Document Number: 268253
Glomerular filtration rate (GFR) increases after a meat meal in several species. The mechanism of this phenomenon is unknown and the excretory and metabolic responses largely unexplored. We examined in humans the nature of the hemodynamic response to a meat meal, the role of salt and water load in this response, and the associated renal excretory responses. Ten normal volunteers were studied after eating an average of 3.5 g/kg body wt of lean cooked beef steak and, on a separate day, after ingesting an amount of sodium and water equivalent to that in the steak. Average GFR increased by 28% for the entire 3 h after the meat meal compared with the same time period after the control salt solution (90 .+-. 8 vs. 114 .+-. 6 ml .cntdot. min-1 .cntdot. 1.73 M-2, mean .+-. SE, P < 0.05) and by 15% compared with the base-line periods, although this difference was not of statistical significance. However, not all subjects demonstrated an increase, and in those eight who did the degree was variable from 5 to 46% for the 3-h mean above the basal value. During the hour of peak GFR, the increment was associated with a nearly proportional increase in renal vascular resistance. the vasodilation was not accompanied by any change in prostaglandin E excretion. Sodium excretion was significantly greater after the meat meal, indicating a natriuretic effect of the meal beyond that expected from its sodium and water content. Excretion of cyclic GMP, but not of cyclic AMP, increased in the hour following the period of peak GFR, a finding consistent with an acute stimulus to renal growth. Hence the human kidney responds to a meat meal with vasodilation and an increase in GFR, a natriuresis, and an augmented excretion of cyclic GMP.