Effect of pentazocine and related compounds on the lipid composition of Ehrlich ascites tumor cells.

The effect of pentazocine and its related compounds on the lipid composition of Ehrlich ascites tumor cells was examined. Ehrlich tumor cells were suspended in Hanks balanced salt solution (pH 7.4) supplemented with 2% bovine albumin (2 x 10(6) cells/ml) and incubated at 37 degrees C for 120 min with and without 10(-3) M of pentazocine, morphine or dihydrocodeine. After incubation, the tumor cell lipids were extracted with chloroform-methanol (2:1, v/v), and they were analyzed quantitatively by the dichromate reduction procedure of Amenta. The tumor cells treated with pentazocine contained lower levels of triglycerides and cholesterol esters as compared with the tumor cells incubated alone. The amounts of triglycerides and cholesterol esters in the tumor cells treated with and without pentazocine were about 82 and 23 mg/10(10) cells and 182 and 55 mg/10(10) cells, respectively (P less than 0.01), whereas there was only a slight difference in the contents of these neutral lipids between the tumor cells treated with and without (10(-3) M morphine or dihydrocodeine. In addition, the fatty acid pattern of triglycerides and cholesterol esters from the pentazocine-treated tumor cells differed markedly from that of the corresponding lipids from the tumor cells incubated alone.