338 



M. WOODS, K. WIGHT, J. HUNTER, D. BURK 



VOL. 12 (1953) 



TABLE Hi 



GROWTH OF S-9I MELANOMAS OF THE SAME TRANSPLANT SERIES IN MALE DBA MICE AT 35° AND 25° C 

 EXPRESSED IN APPROXIMATE TUMOR VOLUMES. EXPOSURE TO CONTROLLED TEMPERATURES BEGAN 20 

 DAYS AFTER TUMOR IMPLANTATION. MICE WERE MAINTAINED ON PURINA CHOW AND WATER AD LIB. 



^ Mouse number 4 died on the second day. 



^ Died on 15th day as result of mechanical strangulation. 



c Died on 36th day presumably as the result of exposure to 35'' C. 



d In all cases, death presumably due to tumor 



In the 35° C series (Table III), tumor growth was also strongly suppressed. Metabolic 

 determinations in shces of tumors of two of the 35° C mice surviving at 44 days showed 

 that, as in the case of the tumors maintained for 12 days at 40° C, a pronounced re- 

 duction in (2c6, had taken place (see previous section). The body weights of the host 

 mice at 35° C, following an initial loss, leveled off at about 12 days and remained fairly 

 constant until about 32 days when a further reduction in weight occurred. Deaths at 

 35° C in this series of 5 mice, which were presumably associated with exposure to high 

 temperature, occurred on the second day (one mouse) and on the thirty-sixth day (one 

 mouse). One mouse died on the fifteenth day as the result of mechanical strangulation. 

 The control (25° C) tumors grew rapidly, deaths of host mice being attributable to this 

 factor. 



While it has long been known^^ that elevating the environmental tem])erature (29° 

 to 37° C) of normal mice increases their sensitivity to insulin (as measured by con- 

 vulsions), the present results show that exposure of melanoma-bearing mice to high 

 temperatures (35° to 40° C) for only 13 to 17 hours is sufficient to markedly alter the 

 in vitro response of the tumor to insulin. In this connection it may be of interest to 

 note that body temperature measurements (rectal; determined by thermocouple) of 

 melanoma-bearing dba mice (average weight of mouse plus tumor == 23 g) showed that 

 after 3 14 hours of exposure to 38° C the average body temperature in 7 mice was 39.2° C 

 (range 38.4° to 39.5°) ; after 31 days exposure of 8 mice to 35° C, was 37.8° C (range 

 37.2° to 38.4°) ; and after 7 hours of exposure of 5 mice to 20° C, was 34° C (range 31.2 

 to 38.0). Nine melanoma-bearing mice maintained 14 days at 26° C (approximately 



References p. 346. 



