THE TEMPERATURE COEFFICIENT OF PHAGOCYTOSIS. 



By WALLACE O. FENN. 

 {From the Laboratory of Applied Physiology, Harvard Medical School, Boston.) 



(Received for publication, November 21, 1921.) 



Recently Madsen and Watabiki (1) have made some accurate 



measurements of the effect of temperature on the phagocytosis 



of bacteria. Fig. 1 is a reproduction of one of their figures showing 



the time curves of the number of bacteria ingested per leucocyte at 



different temperatures. In analyzing these results they endeavored 



to apply the familiar formula for a monomolecular reaction. In 



1 A 



this formula, K= - Log , they took A equal to the maximum 



T A — X 



number of bacteria ingested at the close of the experiment (instead 

 of the maximum number of bacteria present, which, one is led to infer, 

 was larger than A even at the higher temperatures) and x equal, as 

 usual, to the number of bacteria ingested in time, T. 



Considering their method of analysis it is not surprising that they 

 found it impossible to calculate the temperature coefficient of phago- 

 cytosis from their figures. Inspection of Fig. 1 shows that the total 

 number of bacteria ingested is smaller at the lower temperatures, 

 i.e., A is itself a function of temperature, increasing with rise of tem- 

 perature. Now the accelerating effect of the higher temperatures is 

 evidenced quite as much by the increase in A as by the increase in K, 

 as they calculated it. The former factor they have completely dis- 

 counted by their procedure, which is equivalent to ''telescoping" 

 the curves in Fig. 1 on the ordinate so that they all reach the maxi- 

 mum at the same point, and then comparing the times necessary for 

 the different curves to reach the same ordinate. Moreover, the 

 agreement of the experimental data with the formula for a mono- 

 molecular reaction was admittedly unsatisfactory at temperatures 

 above 25°C. where the formula for a bimolecular reaction was usually 

 found to give better results. But even if the results could be expressed 



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