Effect of whole-body potassium depletion on plasma, erythrocyte, and middle gluteal muscle potassium concentration of healthy, adult horses.

The study investigates the impact of food deprivation-induced potassium depletion on the potassium levels within the plasma, erythrocytes, and middle gluteal muscles of healthy adult horses in a period of seven days.

Research Details

• The experiment engaged 16 healthy adult horses that were subjected to food deprivation for 7 days, but they had unrestricted access to water and sodium chloride.
• Throughout this period, the impact of potassium depletion was measured in three areas – the horse’s plasma, erythrocytes (red blood cells), and middle gluteal muscle.
• The concentrations of potassium in these areas were determined using atomic absorption spectroscopy, a technique that identifies the presence and quantity of elements in a sample.

Findings of the Research

• The researchers observed a stable concentration of potassium in the plasma throughout the experiment (3.49 +/- 0.09 mM K/L of plasma).
• Within red blood cells, there was a slight decline in potassium concentration from 93.10 +/- 1.94 mM K/L of erythrocytes on the first day to 88.63 +/- 2.39 mM K/L of erythrocytes on the second day, after which the levels remained constant.
• In the middle gluteal muscle, the concentration of potassium dropped from 91.06 +/- 2.96 microM K/g of muscle to 79.61 +/- 2.09 microM K/g of muscle within 4 days and further to 73.62 +/- 1.85 microM K/g of muscle on the 7th day making for a total decrease of 19.2%.
• There was no correlation found between the plasma and erythrocyte potassium concentrations, the erythrocyte and middle gluteal muscle potassium concentrations, or the plasma and middle gluteal muscle potassium concentrations.
• The study also compared the water content of the muscle and membrane potentials of erythrocytes and muscles. The water content of the middle gluteal muscle remained unchanged, while the membrane potential of the muscle was significantly reduced from -105.84 +/- 1.67 mV to -100.93 +/- 2.10 mV on the 7th day.

Implication

• The findings indicate that prolonged food deprivation can lead to substantial potassium loss in the gluteal muscle of horses, while plasma potassium levels are maintained.
• This information can contribute to better understanding and management of nutrient depletion in horses, particularly when they are experiencing periods of prolonged food deprivation.