Stearoyl-CoA desaturase activity in mammary adenocarcinomas carried by C3H mice.
Transplantable mammary adenocarcinomas and livers of C3H mice fed a stock diet or a linoleate rich diet (15% corn oil) contain similar amounts of oleate (ca 3 mg/gm tissue). On feeding either a high carbohydrate, fat free or a high carbohydrate, saturated fat-containing (15% hydrogenated coconut or cottonseed oil) diet for 6 weeks, oleate levels increased 2-fold in tumor and 5-fold in liver. The specific activity of stearoyl-CoA desaturase in liver microsomes was similar to that in the corresponding fractions of mammary glands of lactating mice. In liver, this activity was enhanced 2- to 3-fold by feeding a high carbohydrate, fat free or a high carbohydrate, saturated fat diet. The desaturase activity in mammary tumor microsomes, while only 10% of that in hepatic microsomes, remained unaltered regardless of the type of diet fed. These observations suggest that (a) a major portion of the oleate in the mammary tumor is not produced within the tissue, (b) dietary adaptation is not a general characteristic of stearoyl-CoA desaturase in neoplastic tissues, and (c) enhanced desaturase activity in liver is directly related to the absence of linoleate or oleate, or to a large decrease in oleate in the diet.
D000230:Adenocarcinoma / Q000201:enzymology*; D000818:Animals; D004032:Diet; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005260:Female; D008041:Linoleic Acids / Q000494:pharmacology; D008325:Mammary Neoplasms, Experimental / Q000201:enzymology; D051379:Mice; D008809:Mice, Inbred C3H; D008861:Microsomes / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology*; D009829:Oleic Acids / Q000378:metabolism; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism*
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D008041:Linoleic Acids; D009829:Oleic Acids; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase