Characterization of lactic acid formation and adenosine triphosphate consumption in calcium-loaded erythrocytes of broiler chickens.
The formation of lactic acid and consumption of adenosine triphosphate (ATP) were measured in erythrocytes from broiler and White Leghorn chickens with the goal of providing further evidence that lactic acid, a metabolite from glycolysis, is an etiological factor for sudden death syndrome (SDS) in broiler chickens. When loaded with Ca2+, erythrocytes exhibited increased lactic acid concentrations. The effect of Ca2+ loading was significantly faster in broiler erythrocytes. In the absence of adenosine used as an energy-yielding substrate, Ca2+ loading was followed by a reduction in ATP concentrations. The effect was also significantly faster in broiler erythrocytes. Intravenous injection of a 20% lactate solution at 0.1 mL/kg produced SDS-like death of broilers but not White Leghorns. The results obtained in erythrocytes indicate that, in broilers, a greater amount of energy is required for regulation of intracellular Ca2+ concentrations, and, thereby, formation of lactic acid is more accelerated. In addition to the result that intravenous lactate injection caused death in broilers, an elevation of lactic acid concentrations in blood, arising from operation of Ca2+ regulation mechanisms, may predispose broilers to incidence of SDS.