Diminished actin polymerization of neonatal neutrophils determined by a microvolume whole blood method.
To investigate the actin response to chemotactic stimulation of neonatal neutrophils, we developed a new procedure to measure neutrophil F-actin content directly in microvolume whole blood (100 microliters sample each test). Using this procedure, we compared neutrophil actin response to N-formyl-methyonyl-leucyl-phenylalanine (FMLP) between groups of normal neonate and adult volunteers. Relative F-actin content (FMLP/control ratio) of neonatal neutrophils is significantly lower than those of adult volunteers' neutrophils both at 30 sec (1.94 +/- 0.34 vs. 2.25 +/- 0.31; n = 16, p < 0.05, t test) and 60 sec (2.23 +/- 0.19 vs. 2.40 +/- 0.27; n = 16, p < 0.05, t test) after FMLP stimulation. These results provide new evidence of impairment of neutrophil actin response in the neonate, which may partially explain the observed chemotactic defect in neonatal neutrophils.
Department of Pediatrics, Kaohsiung Medical College, R.O.C.
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Chen
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Lei
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Lu
D000199:Actins / Q000378:metabolism*; D000328:Adult; D002634:Chemotaxis, Leukocyte; D005434:Flow Cytometry; D006801:Humans; D007231:Infant, Newborn; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D011108:Polymers / Q000378:metabolism
D000199:Actins; D011108:Polymers; D009240:N-Formylmethionine Leucyl-Phenylalanine