LEUKOKINETIC STUDIES. II. A METHOD FOR LABELING GRANULOCYTES IN VITRO WITH RADIOACTIVE DIISOPROPYLFLUOROPHOSPHATE (DFP32)*

Abstract

In a previous publication from this labora- tory (1), radioactive diisopropylfluorophosphate (DFP32), a potent and irreversible esterase in- hibitor, was shown to be a suitable label for granulocytes.Evidence was presented that the label is firmly attached to granulocytes; it does not modify the viability of the cells, and the label is not reutilized when the cells are degraded.Experiments designed to determine whether or not elution of the label occurs failed to provide such evidence.More recent studies (2), carried out with tritiated DFP and autoradiography, have con- firmed the observation that the label is attached to granulocytes and little, or not at all, to lymphocytes or to monocytes.A method for labeling granulocytes in vivo with DFP32 was described in the previous publication (1).The purpose of this paper is to describe a method for labeling granulocytes in vitro, and to describe the manner in which granulocytes so labeled leave the circulation of normal subjects.Several preliminary reports of this work have been published (3, 4). MATERIAL AND METHODSSubjects.A total of 82 volunteers from the Utah State Prison was used in these studies.All of the subjects were normal, healthy males, 20 to 50 years of age, with normal leukocyte values.Each subj ect was used only once in the study.All of the studies were started be- tween 8 and 10 a.m.Method of labeling granulocytes in vitro.Five hundred ml of -blood was withdrawn from the subject into a sterile, plastic bag 1 containing 67.5 ml of ACD-A solu-* This investigation was supported in part by research grants (C-2231 and CY-2349) from the National Cancer Institute and in part by a graduate training grant (2A- 5098) from the National Institute of Arthritis and Met- abolic Diseases, Bethesda, Md.