ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
When human granulocytes that have been primed with recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSFrh) are activated by ligands that stimulate the respiratory burst, the amount of superoxide anion (O-2) they generate is significantly increased. We have found that the accelerated rate of O-2 release occurring under these conditions is accompanied by an antecedent increase in membrane depolarization. We examined the nature of the enhancement of membrane depolarization in GM-CSFrh-primed granulocytes and investigated its relationship to the increase in O-2 generation by N-formyl methionylleucylphenylalanine (fMLP)-activated granulocytes. We found that augmented depolarization could not be accounted for by a change in the resting membrane potential induced by the growth factor and was still present after either blocking passive transmembrane Na+ movement with dimethylamiloride or by increasing the membrane's permeability to K+ with valinornycin. When their ability to depolarize was virtually eliminated by dissipating the transmembrane K+ gradient, GM-CSFrh-pretreated cells continued to generate more O-2 after fMLP than did control cells. These results indicate that augmentation of the granulocyte's ability to generate O-2 anions, which is induced by priming with GM-CSFrh, is independent both of the resting transmembrane potential and of alterations in the extent of membrane potential change induced by stimuli such as fMLP.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041390219
