Plasma catecholamine and glucose concentrations during hemorrhagic hypotension in anesthetized dogs

Abstract

Hemorrhage-induced hepatic glycogenolytic responses were compared in pentobarbital-anesthetized dogs with a temporary functional adrenalectomy (ADRX) and in dogs with an acute hepatic denervation (HNX). Plasma concentrations of catecholamines [CAs; epinephrine (E), norepinephrine (NE), and dopamine (DA)] were determined in aortic (AO), hepatic venous (HV), portal venous (PV), and adrenal venous (ADV) blood collected simultaneously before, during, and after hemorrhage (H). Plasma glucose (GL) concentrations were measured in AO and HV blood. AO blood was bled (5.3 +/- 0.5 ml.kg-1.min-1, n = 42) until AO systolic pressure dropped to half (72.9 +/- 4.7 mmHg) of its control value (148.0 +/- 4.4 mmHg), and the hypotension was maintained for 5 min. In control dogs (CTL; n = 12), H markedly increased ADV CAs with a predominant increase in E over NE and DA. AO CAs increased similarly. By contrast, however, changes in HV CAs were characterized by a significant increase in NE that was more pronounced than the increases in E and DA. The increases in NE were associated with significant increases in both HV GL and AO GL. In dogs with ADRX (n = 10), AO CAs remained unchanged during H, but both HV NE and HV GL rose concomitantly to an extent similar to that observed in CTL dogs. In dogs with HNX (n = 10), HV NE remained unchanged during H, but HV GL increased to an extent similar to that observed in dogs with ADRX, along with significant increases in AO CAs. In dogs with HNX combined with ADRX (n = 10), HV NE and AO CAs did not change at all during H, resulting in a marked attenuation (50%, P less than 0.05) of the increasing response of HV GL.(ABSTRACT TRUNCATED AT 250 WORDS)