VOL. 12 (1953) ASCITIC TUMORS AND THEIR HOST'S BLOOD PLASMAS 



165 



For the studies reported here, twenty to thirty mice of the dba or the C albino strain were inoc- 

 ulated intraperitoneally with 0.2 ml of a 6- or 7-day old appropriate ascites tumor cell suspension. 

 At time of inoculation, usually four mice were sacrificed and bled. The pooled plasma was analyzed 

 for the enzymes aldolase, isomerase, and a-glycerophosphate dehydrogenase. After five days, in the 

 case of the Ehrlich carcinoma, and six days for the thymoma, 4 to 6 animals were killed and bled. The 

 ascitic cell suspensions were removed from the peritoneal cavities and pooled after addition of o.i mg 

 of heparin per ml of suspension. Aliquots of the ascitic cell suspension were put into two ordinary 

 Warburg respirometer vessels, gassed with 95% Nj plus 5% COg in one case and with 95% Og plus 

 5% COg in the other, and shaken gently for one and a half hours at 37° C to keep the cells from sedi- 

 menting. The suspensions were then centrifuged at 500 g for 10 minutes at room temperature in a 

 horizontal centrifuge. The cell-free ascitic fluids were analyzed and the results compared with those 

 obtained with the ascitic fluid from an aliquot of the same cell suspension centrifuged immediately 

 after removal from the animals. 



350 



300 



o 



I 



250 



200- 



150- 



100 



50 







□ Blood plasma 

 ■ Ascilic fluid 



a- Glycerophosphate 

 dehydrogenase 



Aldolase 



Isomerase 



I 



I 



I 



M. 



6 9 13 



6 9 



13 6 9 13 



Days after inoculation 

 Fig. I. dba Ascites thymoma. Aldolase, isomerase, and a-glycerophosphate dehydrogenase concentra- 

 tions in blood plasma of normal dba mice, and in blood plasma and ascitic fluid of dba mice 6, 9, and 13 

 days after intraperitoneal inoculation with dba ascites thymoma. 



RESULTS 



A summary of results from a typical experiment with the ascites thymoma in dba 

 mice is given in Fig. i which illustrates a comparison of the enzyme activity levels for 

 aldolase, isomerase and a-glycerophosphate dehydrogenase in the blood plasma and fresh 

 ascitic fluid of animals sacrificed 6, 9, and 13 days after tumor inoculation. With this 

 tumor, under the cultural conditions employed, the fifth or sixth day after inoculation 

 was the earliest that the tumor had sufficiently developed (0.5 to i.o ml) to permit rapid 

 and convenient accumulation of adequate ascitic cell suspension for the tests reported. 

 By 13 days, 4 to 7 ml of tumor material per animal were available and the host was 



References p. iji. 



