Diets High in Corn Oil or Extra-Virgin Olive Oil Provided From Weaning Advance Sexual Maturation and Differentially Modify Susceptibility to Mammary Carcinogenesis in Female Rats

摘要

Based on the importance of early-life events in breast cancernrisk, we have investigated the effects of high-fat diets on matura-ntion, mammary gland development, and its susceptibility to trans-nformation. Female Sprague-Dawley rats were fed a lowfat (LF),nhigh corn oil (HCO), or high extra-virgin olive oil (HOO) diet fromnweaning and gavaged with 7,12-dimethylbenz[a]anthracene. Bodynweight and mass increased in the HCO group compared to the LFngroup. The vaginal opening was advanced in both high-fat groups,nespecially in the HCO group. This HCO group also had increasednbody weight around puberty, more corpora lutea at post-puberty,nand tended to have higher kisspeptin levels in the hypothalamus.nBoth high-fat diets induced subtlemodifications in themorphologynof the mammary gland, with no changes on β-casein or hormonenreceptors expression in the gland. TheHCOdiet had a clearly stim-nulating effect of carcinogenesis, inducing the earliest appearancenof tumors and the highest tumor incidence and yield, whereas thenHOO diet seemed to have a weak enhancing effect, increasing tu-nmor yield. Our data suggest a strong influence of the HCO diet in sexual maturation and mammary cancer risk, while rats fed thenHOO diet were more similar to the controls.