366 RESPIRATORY METABOLISM 



5. THE EFFECT OF TEMPERATURE ON O2 CONSUMPTION 



Data concerning the effect of temperature on O^ consumption are not 

 numerous, and in most cases are incomplete. Barratt (1905) determined 

 the CO2 production of Paramecium at various temperatures and found 

 that the rate at 27°-30° C. was more than twice that at 15° C. Wachen- 

 dorff (1912) found that C. colpoda respired about four times as fast at 

 17° as at 7° C. Leichsenring (1925) demonstrated that Varamecium, 

 when transferred from a temperature of 20° C. to one of 35° C, showed 

 a respiratory increase of 35 percent, and that when transferred to a 

 temperature of 15°, 10°, 5°, 0° C. respiration was decreased 30 per- 

 cent, 34 percent, 50 percent, and 58 percent respectively. These effects 

 were not completely reversible. The data of Kalmus (1928b) showed 

 a Q^„ value (temperature coefficient) of 1.5 for Paramecium respira- 

 tion between 23° and 32° C. A. Lwoff (1933) found a Q^^ value of 2.1 

 between 13° and 23° C, and about 1.5 between 23° and 32° C. The 

 temperature characteristic (p value) was 9,830 calories for the range 13° 

 to 34° C. Lwoff also calculated a |j value of 21,350 for the synthesis 

 of respiratory enzyme (oxidase, see below) by the organism between 

 18° and 31.5° C, and a value of — 52,000 between 31.5° and 

 34.0° C. 



6. THE EFFECT OF ANESTHETICS AND POISONS ON O, CONSUMPTION 



The effect of various toxic agents (e.g., KCN, CO, N3H, arsenite, 

 urethanes, and so forth) which are supposed to exert a specific effect 

 on the normal functioning of certain respiratory enzymes, will be dis- 

 cussed in connection with the mechanism of respiration. The effect of 

 other anesthetics on respiration has not been extensively studied. Leich- 

 senring (1925) found that ethylene and nitrous oxide had no effect on 

 the respiration of Paramecium, and that ether and chloroform produced 

 decreases of as much as 25 percent (after two and one hours respec- 

 tively). The effect was reversible with ether, but not with chloroform 

 if the exposure was more than one-half hour. Colpoda was more sensitive 

 to these substances than Paramecium. Von Fenyvessy and Reiner (1928) 

 found no decrease in respiration of Trypanosoma equiperdum when one- 

 percent Germanin was added. This was surprising, in view of the fact 

 that Germanin is very toxic for trypanosomes in vivo. 



