Hypertriglyceridemia in Ehrlich ascites carcinomatous mice: tumor and mouse strain differences

Ehrlich ascites carcinoma growth in mice induces hypertriglyceridemia. The degree of hypertriglyceridemia found in one laboratory (Spector's) was much greater than we observed in our laboratory. Moreover, major differences were reported with respect to fasting (no effect on tumor extracellular fluid triglyceride levels in Spector's tumor-bearing mice; marked decrease in ours). We have obtained tumorous CBA mice from Spector's laboratory and have studied them simultaneously with our Swiss-Webster mice. Triglyceride levels of the above two groups and from two controlled crossover groups, included to evaluate the influence of mouse and tumor strains on hypertriglyceridemia, were determined. The CBA mice had intense hypertriglyceridemia and high triglyceride levels in tumor extracellular fluid regardless of the subline source of ascites tumor. On the other hand, only mild hyperlipidemia was induced with both strains of tumor in Swiss-Webster mice. Thus, the variations in plasma and tumor extracellular fluid triglyceride levels probably arise from the mouse strains and not from variations in the tumor subline. Fasting caused a decrease in both plasma and tumor extracellular fluid triglyceride concentrations in CBA, as well as in Swiss-Webster mice. A mouse strain difference was also evident from a significant decrease in wet weights of adipose tissues like epididymal fat, inguinal fat, and intermuscular fat with tumor growth in the CBA strain which was not observed in the Swiss-Webster strain at the corresponding stage of tumor growth. Study of these strain diffeences may lead to an understanding of factors that regulate hyperlipidemia.