Potential role of a liver-derived factor in mediating renal response to protein.

Increases in renal blood flow and glomerular filtration rate occur following the ingestion of a protein-rich meal. It has been postulated that this renal response is stimulated by some hormonal factor. Glucagon has been proposed as a probable mediating hormone, but results of recent studies argue against a direct mediating effect of glucagon. It is postulated that glomerular hyperfiltration induced by various stimuli (protein ingestion, amino acid infusion, glucagon infusion, diabetes mellitus) is associated with increased secretion by the liver of a factor that increases glomerular filtration rate. Preliminary data suggest that serotonin might play a role in mediating the postprandial increases in renal hemodynamics following protein ingestion.