Effect of acid-base alterations on hepatic lactate utilization

Area of Science:

• Physiology
• Biochemistry
• Hepatic Metabolism

Background:

• Hepatic lactate utilization is crucial for acid-base balance.
• The impact of acid-base disturbances on lactate metabolism requires further clarification.

Purpose of the Study:

• To investigate the effect of acid-base changes on hepatic lactate utilization in vivo.
• To determine the primary factors influencing hepatic lactate uptake during altered acid-base states.

Main Methods:

• Anesthetized, mechanically ventilated dogs were used.
• Hepatic and arterial blood flows and lactate concentrations were measured.
• Hepatic lactate uptake was calculated using the Fick principle.

Main Results:

• Respiratory alkalosis significantly increased arterial lactate concentration and hepatic lactate utilization, despite decreased liver blood flow.
• Tris buffer infusion, respiratory acidosis, and metabolic acidosis did not significantly alter hepatic lactate uptake.
• Hepatic lactate utilization strongly correlated with arterial lactate concentration during alkalosis and lactate infusion.

Conclusions:

• The hyperlactatemia observed during alkalosis is not caused by impaired hepatic lactate utilization.
• Blood lactate concentration, rather than liver blood flow or acid-base status, is the main determinant of hepatic lactate uptake.