Leukokinetic Studies. VIII. A Search for an Extramedullary tissue Pool of Neutrophilic Granulocytes. ∗

Summary

This study was designed to determine whether inflammatory granulocytes are derived solely from the blood or from a hypothetical extramedullary tissue pool of granulocytes, in addition to the blood. Blood granulocytes were labeled in vitro with DFP³², infused, and their subsequent appearance in induced inflammatory exudates studied. From a comparison of the maximum blood granulocyte specific activity and the exudate granulocyte specific activity it was evident that at least three-fourths of the exudate neutrophils were derived directly from the blood. To determine if more than three-fourths of the exudate neutrophils were from the blood the proportion of granulocytes in an exudate 4 hours old which had left the blood during each of the preceding 4 hours was calculated. It was found that approximately 36% of the granulocytes in a 4 hour exudate had left the blood during the first hour of inflammation. The figures for the 2nd, 3rd and 4th hours of inflammation were, respectively, 32%, 25% and 9%, making a total of 102%. If significant numbers of un-labeled granulocytes from the tissues had entered the exudate, the summation of these percentages should have been substantially less than 100%. Consequently, these studies provide no evidence for the existence of a tissue pool of granulocytes.

We are indebted to Miss Helen Ashenbrucker for technical assistance. The cooperation of Dr. William Knott, Warden John Turner and the inmates of the Utah State Prison is sincerely appreciated. Dr. Paul Hoeprich kindly maintained the culture of staphylo-cocci used.