Hepatic energy status in hypotension of different aetiologies in dogs

1. The alterations in hepatic energy metabolism in hypotension induced by the administration of trimetaphan camsylate (Arfonad) were investigated in comparison with those produced by hypotension resulting from massive haemorrhage by measuring the arterial ketone body ratio, which reflects the hepatic mitochondrial redox state, and other indices of hepatic energy metabolism together with simultaneous measurement of hepatic blood flow in dogs. 2. Mean arterial blood pressure was decreased from 130 mmHg to 60 mmHg by the continuous intravenous infusion of trimetaphan camsylate or by the use of Wiggers' shock model. In hypotension induced by trimetaphan camsylate, the arterial ketone body ratio, ATP and total adenine nucleotide concentrations and energy charge were maintained at near-control values throughout the experimental period. By contrast, the arterial ketone body ratio decreased from 1.04 +/- 0.09 to 0.29 +/- 0.06 at 3 h after haemorrhage in Wiggers' shock model (P less than 0.01). The ATP and total adenine nucleotide concentrations and energy charge also decreased significantly in this model (P less than 0.05). The difference in hepatic energy status was also shown by data from 31P nuclear magnetic resonance spectroscopy. 3. During hypotension, portal venous and total hepatic blood flows diminished significantly compared with the control values in each group (P less than 0.01). Although there was no significant difference in total hepatic flow between the two groups, the portal venous blood flow in hypotension induced by trimetaphan camsylate was significantly higher than that in Wiggers' shock model (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)