Role of the LympJiocyte in Inflammation 79 



At the 23 hour and 15 minute stage of the inflammatory response, 

 motile macrophages of lymphocytic origin had the characteristics of a 

 supravital "monocyte." These characteristics include a large cell body, 

 a kidney bean-shaped nucleus, a neutral red rosette near the nuclear 

 notch, a constant undulation of the cell body, and delicate pseudopodia 

 extending in many directions. 



DISCUSSION 



Lymphocytes play a dynamic role in the inflammatory response. Their 

 known functions are roughly divisible into four major types: immunologic, 

 trephocytic, cytopoietic, and phagocytic phenomena. These functions are 

 often closely related, and this didactic classification is of necessity some- 

 what arbitrary. The experiments cited in this report are concerned 

 primarily with those functions related to phagocytosis. 



Metchnikoff in 1888 first described the migration and hypertrophy of 

 lymphocytes in rabbits and marmots infected with tubercle bacilli. In 

 addition to his lectures in 1892, in which he demonstrated conclusivelv 



the lymphocyte > macrophage transformation, six other confirmatorv 



reports were published by 1900. 



In 1902 Maximow published a 262-page review of his own experiments 

 on inflammation. He confirmed the motility of lymphocytes and their 

 emigration from vessels to the area of inflammation as well as their trans- 

 formation into macrophages. Up to 1950, over 70 similar confirmatory 

 reports were published.' 5 ' 4 Many of these papers stress the importance of 

 studying the inflammatory response in the early hours. 



The skin window and related techniques are simple, reliable methods of 

 studying the early changes in humans and laboratory animals. They con- 

 firm and extend the studies of Metchnikoff. 



The tissue macrophages are the first cell to respond to the inflammatory 

 stimulus when it is applied to connective tissue. The neutrophils or their 

 equivalent (pseudoeosinophils, etc.) are usually the first of the hematogenous 

 cells present at the inflammatory site. In man they are present within 1 hour 

 and comprise the majority of the exudate cells for the first 10 to 11 hours 

 in these experiments. After the twelfth hour, they are present in decreased 

 numbers and often show severe degeneration changes. At 3 hours, only 

 a few lymphocytes are present. Six hours after the onset, they comprise 

 about a third of the exudate cells. From 2 to 14 hours and later, they are 

 slightly hypertrophied and the predominant cell type. At 14 hours the 

 average cell diameters show only a light increase ranging between 1 1 and 

 13 jx. At 21 hours the value is from 14 to 17 fx. At 21 hours and later, they 

 continue to increase their nuclear and cytoplasmic mass and become indis- 



