CAN DIETARY FAT--MAMMARY GLAND GROWTH PROCESSES

在人类中有越来越多的流行病学证据表明，高水平的 饮食中的脂肪可能会增加一些器官的癌症发病率 部位，特别是乳房、前列腺和结肠。在各种各样的 人类乳腺癌的实验动物模型，这是相当明显的 脂肪的过度营养促进了乳腺肿瘤的发生，即， 实验动物的乳腺癌发病率增加 摄入高水平的膳食脂肪。不仅脂肪的数量很重要， 但脂肪的类型也显著影响了这一肿瘤过程。在……里面 一般说来，大多数植物脂肪(其中大多数都含有高水平的 不饱和脂肪酸)比动物有效得多 肉类脂肪(富含饱和脂肪酸)可促进 动物乳腺肿瘤发生的实验研究。相比之下，鱼油 (富含多不饱和脂肪酸)，当大量喂养时，不 似乎能促进实验动物乳腺肿瘤的发生 模特们。某些高脂饮食促进乳腺生长的机制(S) 腺体肿瘤的发生机制尚不清楚。 我们在问两个非常基本的问题。一、能不能过度营养 脂肪会影响正常乳腺的发育生长过程吗？ 第二，脂肪的类型会影响这一重要的过程吗？到目前为止，我们做到了 我不知道这两个重要和必要的问题的答案 问题。为了回答这些问题，我们将确定比较 三大营养促进哺乳动物生长的活动 脂肪类别，即植物脂肪(玉米油、橄榄油、椰子油)， 动物肉脂(猪油、牛油)和鱼油(曼哈登油)。每个人 这些脂肪的脂肪酸组成差异很大，而且 代表了人类消费的各种脂肪。 重要的是，这些脂肪中的每一种在它们的 增强实验动物乳腺肿瘤形成的能力。 将评估雌性Balb/c小鼠的乳房生长过程； 生长，作为饮食的函数，将在正常的循环中在体内决定 在小鼠和用促乳房激素治疗的小鼠中。乳房激素诱导 生长反应，作为饮食的函数，也将在 短期器官培养分析。乳腺生长的量化 将通过(1)形态整体评估，(2)上皮 计算机图像分析的面积分析和(3)上皮DNA合成 通过~3H-胸腺嘧啶核苷放射自显影分析。

There is increasing epidemiological evidence in humans that high levels of dietary fat may increase the incidence of cancer in a number of organ sites, in particular, the breast, prostate and colon. In a wide variety of experimental animal models for human breast cancer, it is quite apparent that hyperalimentation of fat enhances mammary gland tumorigenesis, i.e., the incidence of mammary carcinomas is increased in experimental animals fed high levels of dietary fat. Not only is the quantity of fat important, but the type of fat also markedly influences this neoplastic process. In general, most vegetable fats, (most of which have high levels of unsaturated fatty acids) are substantially more efficacious than animal meat fats (rich in saturated fatty acids) in the enhancement of experimental animal mammary gland tumorigenesis. In contrast, fish oils (rich in polyunsaturated fatty acids), when fed in large amounts, do not appear to enhance mammary gland tumorigenesis in experimental animal models. The mechanism(s) by which certain high fat diets enhance mammary gland tumorigenesis is unknown. We are asking two very fundamental questions. One, can hyperalimentation of fat affect developmental growth processes of the normal mammary gland? Two, can the type of fat influence this important process? To date, we do not know the answer to either one of these important and essential questions. To answer these questions, we will determine the comparative mammae growth promoting activities of hyperalimentation of three major classes of fat, i.e., vegetable fats (corn oil, olive oil, coconut oil), animal meat fats (lard, beef tallow) and a fish fat (Menhaden oil). Each of these fats differ widely in their fatty acid composition and are representative of the wide range of fats consumed by human populations. Importantly, each one of these fats also differ substantially in their ability to enhance mammary gland tumorigenesis in experimental animals. Mammae growth processes will be assessed in female Balb/c mice; mammary growth, as a function of diet, will be determined in vivo in normal cycling mice and in mice treated with mammogenic hormones. Mammae hormone induced growth responsiveness, as a function of diet, will also be determined in short term organ culture analysis. Quantification of mammary gland growth will be enacted by (1) morphological wholemount evaluation, (2) epithelial area analysis via computer image analysis and (3) epithelial DNA synthesis via 3H-thymidine autoradiographic analysis.