Circulating levels of neuropeptides (CGRP, VIP, NPY) in patients with fulminant hepatic failure

The present study investigated the circulating levels and cerebral fluxes o f calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VI P), and neuropeptide Y (NPY) and their relation to cerebral blood flow (CBF ) during normoventilation and hyperventilation in patients with fulminant h epatic failure (FHF). Sixteen patients with FHF were studied and compared t o six patients with cirrhosis of the liver. CBF was measured by the Xe-133 wash-out technique. Blood samples were obtained simultaneously from the art ery and internal jugular bulb. Concentrations of CGRP and VIP were higher i n FHF than in cirrhosis, 87 (55-218) vs 29 (21-42) pmol/L, and 11 (6-29) vs 5 (3-9) pmol/L, respectively. NPY was normal, none of the measures were re lated to CBF, and there was no detectable net brain fluxes. Hyperventilatio n did not alter any of the measures. CGRP and VIP in FHF seem to reflect he modynamic changes in the systemic rather than in the cerebral circulation. (C) 2001 Harcourt Publishers Ltd.