Exogenous L-lactate clearance in adult horses.

This study aimed to investigate the production of L-Lactate, a substance produced by the body, and how well it was cleared from the body, using a solution known as exogenous sodium L-Lactate, in healthy adult horses.

Research Methods

• Exogenous sodium L-lactate solution was prepared with a concentration of 1 mmol/kg of body weight, diluted in 500 mL of 0.9% NaCl (sodium chloride solution).
• This solution was then administered intravenously into the horses over a duration of 15 minutes.
• Several blood samples were taken from the horses to measure L-Lactate concentration. Instances of sample collection included: just before the infusion (baseline), at 5-, 10-, 15-minute intervals during the infusion, at 1-minute intervals for 15 minutes immediately following the infusion, and then 30-, 45-, 60-, 120-, 180-minutes after the infusion.
• Data obtained from these samples was then input into a software program for pharmacokinetic analysis and modeling. This allowed for the calculation of factors such as the clearance rate of exogenous L-Lactate, as well as how quickly it was eliminated from the body (t(1/2) β).

Research Subjects

• The study was conducted on six clinically healthy adult horses, housed at a University Teaching Hospital.

Results

• Baseline lactate levels in the horses varied, with a range of 0.20-0.72 mmol/L.
• The lactate level just before the administration of ExLC was generally consistent, with a median of 0.43 mmol/L, showing minor variations primarily associated with each horse’s individual characteristics.
• Using a 2-compartment model for pharmacokinetic parameters, the median clearance rate of ExLC was found to be 1.05 L·h(-1) ·kg(-1), while the median elimination half time was estimated at 29.54 minutes.
• Based on the baseline lactate levels, the median lactate production in the horses was determined to be 0.49 mmol·h(-1) ·kg(-1).

Conclusion

• The research concluded that ExLC in healthy adult horses was greater than in humans suffering from high lactate levels, but similar to humans with normal lactate levels who are unwell, when examined using the same model. This insight supports the further development of species-specific and disease-specific ExLC parameters.