Serotoninergic hepatorenal reflex regulating renal glomerular filtration rate.

Infusion of glutamine (2 mumol/min) into the superior mesenteric vein leads to a decrease of renal glomerular filtration rate (GFR) and urinary flow rate (V), whereas infusion of identical amounts of glutamine into the jugular vein does not significantly alter GFR or V. The effect of mesenteric glutamine is mimicked by mesenteric infusion of 5 nmol/min serotonin and is abolished in the presence of 20 nmol/min methysergide. The effect of mesenteric serotonin is almost abolished after transection of vagal hepatic nerves. The observations point to a serotoninergic hepatorenal reflex regulating renal function.