title: Cl⁻/HCO₃⁻ exchange activity in fMLP-stimulated human neutrophils.
abstract: It is well known that chemotactic agents active Na(+)/H(+) exchanger, increasing intracellular pH of neutrophils, but their effect on bicarbonate transporters have not been established yet. To study the effect of fMLP on the activity of Cl(-)/HCO(3)(-) exchange, the rate of pH recovery after acute Cl(-) readmission in cell subjected to an alkaline load by CO(2) washout in a Cl-free medium was measured. The activity of the exchanger was reduced to 72% of control when cells were pre-incubated for 5 min with 0.1 μM fMLP and reached 48% of control in steady state after acute exposure. After extracellular bicarbonate or TMA addition the rate recovery of intracellular pH was reduce at 72% and at 84%, respectively. The inhibitory effect on the intracellular pH recovery was not affected by blockers of Na(+)/H(+) exchange. We conclude from these studies that an increase of pH(i) produced for this chemotactic agent is facilitated by the simultaneous activation of Na(+)/H(+) exchange and inhibition of Cl(-)/HCO(3)(-) exchange in neutrophils.
authors: Centro de Investigaciones Cardiovasculares, CCT La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, 1900 La Plata, Argentina. miriamgiambelluca@conicet.gov.ar
authors: Miriam S
authors: MS
authors: Giambelluca
authors: Oscar A
authors: OA
authors: Gende