Abstract
The divalent cation chelators, ethyleneglycoltetraacetic acid (EGTA) and its magnesium salt, MgEGTA, were compared in studies of alternative complement pathway function. EGTA (0.01 M) inhibited both the rate and the amount of complement activation by zymosan whether compared to nonchelated serum or to serum chelated with MgEGTA (0.01 M). The rate of alternative pathway activation by zymosan was slightly slower in MgEGTA-chelated serum than in nonchelated serum, but the overall amount of complement consumed by a given amount of zymosan was not decreased. MgEGTA chelation spontaneously activated the alternative pathway, as reflected by lysis of erythrocytes from a patient with paroxysmal nocturnal hemoglobinuria. No evidence could be found that MgEGTA either spontaneously activated C2 or facilitated zymosan activation of C2. Suggested guidelines for the use of these chelators are advanced.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bryan C. S. Sensitization of E. coli to the serum bactericidal system and to lysozyme by ethyleneglycoltetraacetic acid. Proc Soc Exp Biol Med. 1974 Apr;145(4):1431–1433. doi: 10.3181/00379727-145-38028. [DOI] [PubMed] [Google Scholar]
- Bryant R. E., Jenkins D. E., Jr Calcium requirements for complement dependent hemolytic reactions. J Immunol. 1968 Oct;101(4):664–668. [PubMed] [Google Scholar]
- Des Prez R. M., Bryan C. S., Hawiger J., Colley D. G. Function of the classical and alternate pathways of human complement in serum treated with ethylene glycol tetraacetic acid and MgCl2-ethylene glycol tetraacetic acid. Infect Immun. 1975 Jun;11(6):1235–1243. doi: 10.1128/iai.11.6.1235-1243.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fine D. P. Activation of the classic and alternate complement pathways by endotoxin. J Immunol. 1974 Feb;112(2):763–769. [PubMed] [Google Scholar]
- Fine D. P., Marney S. R., Jr, Colley D. G., Sergent J. S., Des Prez R. M. C3 shunt activation in human serum chelated with EGTA. J Immunol. 1972 Oct;109(4):807–809. [PubMed] [Google Scholar]
- Forsgren A., Quie P. G. Opsonic activity in human serum chelated with ethylene glycoltetra-acetic acid. Immunology. 1974 Jun;26(6):1251–1256. [PMC free article] [PubMed] [Google Scholar]
- Götze O., Müller-Eberhard H. J. Paroxysmal nocturnal hemoglobinuria. Hemolysis initiated by the C3 activator system. N Engl J Med. 1972 Jan 27;286(4):180–184. doi: 10.1056/NEJM197201272860403. [DOI] [PubMed] [Google Scholar]
- Lew F. T., Yukiyama Y., Waks H. S., Osler A. G. Activation of the alternative (properdin) pathway by divalent cations. J Immunol. 1975 Sep;115(3):884–888. [PubMed] [Google Scholar]
- May J. E., Rosse W., Frank M. M. Paroxysmal nocturnal hemoglobinuria. Alternate-complement-pathway-mediated lysis induced by magnesium. N Engl J Med. 1973 Oct 4;289(14):705–709. doi: 10.1056/NEJM197310042891401. [DOI] [PubMed] [Google Scholar]
- Platts-Mills T. A., Ishizaka K. Activation of the alternate pathway of human complements by rabbit cells. J Immunol. 1974 Jul;113(1):348–358. [PubMed] [Google Scholar]
- Sandberg A. L., Osler A. G. Dual pathways of complement interaction with guinea pig immunoglobulins. J Immunol. 1971 Nov;107(5):1268–1273. [PubMed] [Google Scholar]
- Snyderman R., Pike M. C. Interaction of complex polysaccharides with the complement system: effect of calcium depletion on terminal component consumption. Infect Immun. 1975 Feb;11(2):273–279. doi: 10.1128/iai.11.2.273-279.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]