Dietary lipid effects on the growth, membrane composition, and prolactin-binding capacity of rat mammary tumors.
The effects of qualitative and quantitative differences in dietary lipid on the growth of N-methyl-N-nitrosourea (CAS: 684-93-5)-initiated mammary tumors were evaluated in inbred female (F344) rats. Specific prolactin-binding measurements and qualitative lipid analyses were performed on both tumor and hepatic microsomes from these animals. Our results indicated that 1) when the polyunsaturated lipid component (corn oil) of the diet exceeded 3%, it was the quantitative level of total lipid, rather than the level of polyunsaturated lipid alone, that best correlated with the observed reduction in tumor latent period; 2) when the polyunsaturated lipid content of the diet fell below 3%, there was a decrease in tumor incidence and an increase in the mean latent period; 3) only those changes in tumor development that occurred when the dietary polyunsaturated lipid content was below 3% were associated with alterations in specific prolactin binding capacity.
D000818:Animals; D002369:Castration; D002455:Cell Division / Q000187:drug effects; D004041:Dietary Fats / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000473:pathology / Q000503:physiopathology*; D008563:Membrane Lipids / Q000032:analysis; D008770:Methylnitrosourea / Q000633:toxicity; D008861:Microsomes / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011981:Receptors, Prolactin
D004041:Dietary Fats; D005227:Fatty Acids; D008563:Membrane Lipids; D011956:Receptors, Cell Surface; D011981:Receptors, Prolactin; D008770:Methylnitrosourea; D011388:Prolactin