calcimycin and 3-phosphoglycerate

Treatment of rabbit polymorphonuclear leukocytes (PMNs) with 20 mM sodium fluoride for 10 min, followed by removal of fluoride and addition of Ca2+ results in extensive exocytosis. This is apparent from a strong lysozyme release, together with a slight LDH release. During fluoride-activated Ca2+-dependent exocytosis an increase of indo fluorescence and a strong association of 45Ca with the cells occurs. Different inhibitors inhibit both 45Ca association and lysozyme release. Pretreatment of PMNs with pertussis toxin, or the presence of AI3+ in the medium has little effect on fluoride-activated Ca2+-dependent exocytosis. During pretreatment with fluoride, the ATP level strongly decreases. Exocytosis nevertheless occurs upon addition of Ca2+, indicating that a normal ATP level is not required for exocytosis. The glycogen content of the cell strongly decreases during exposure to Ca2+ after pretreatment with fluoride, but not during pretreatment with fluoride. Breakdown of glycogen and accumulation of 3-phosphoglycerate suggest that glycolysis is blocked at the enolase step, but proceeds as far as that step.

Topics: Adenosine Triphosphate; Animals; Calcimycin; Calcium; Calcium Radioisotopes; Exocytosis; Glyceric Acids; Glycogen; Glycolysis; L-Lactate Dehydrogenase; Muramidase; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Rabbits; Sodium Fluoride; Tetradecanoylphorbol Acetate