Effects of Platelet Activating Factor on Membrane Potential and Respiratory Burst Activity of Human Granulocytes.
Van Dyke-K; Castranova-V
Cellular Chemiluminescence 1987;:158-166
The effects of platelet activating factor (PAF) on membrane potential and respiratory burst activity of human granulocytes were studied in-vitro. Granulocytes prepared from blood drawn from healthy volunteers were incubated with 0 to 10(-4) molar PAF in the presence or absence of extracellular sodium ion (Na+) or calcium-45 (Ca-45) tagged calcium-chloride. The effects on transmembrane potential and hydrogen-peroxide release were determined by fluorescence techniques. Oxygen consumption was measured. Superoxide anion release was determined by a spectrophotometric procedure. Chemiluminescence of the cells was measured by liquid scintillation counting. Uptake of Ca-45 was measured. PAF caused a rapid transient depolarization of the granulocyte membranes in the presence of extracellular Na+. In the absence of Na+, PAF had no effect on membrane potential. Uptake of Ca-45 was not affected by PAF or the presence or absence of extracellular calcium-chloride. PAF treated cells generated chemiluminescence only when Na+ was present in the medium. PAF induced a moderate release of hydrogen- peroxide and a weak release of superoxide anion. Oxygen consumption was not affected. The authors conclude that PAF causes a Na+ dependent activation of human granulocytes. This response may be involved in the inflammatory process.
In-vitro-studies; Blood-cells; Humans; Bioactivation; Physiological-chemistry; Laboratory-techniques; Platelets; Cell-function; Bioelectric-effects; NIOSH-Author;