[SOUND] So here's some examples of where elevated estrogen might be coming from internally. So again, our two unusual situations are Cystic ovaries and particularly, Ovarian tumors. Let's think about where are there might be some external sources of estrogen so to everyone talk about very briefly your files and selling them to look at this is a wide range of kinds of compounds coming from the wide range of plants. So a diverse group of plant-derived compounds that have estrogenic activity. These were discovered back in the 1930s, so a lot is known about them at this point. Structural similarities, so these things, many of these compounds have structural similarities to estradiol, which is kind of the major estrogen. That has an impact in mammals. And the structural similarity actually allows them to bind to estrogen receptors and this is how they have one type of function or another. Different general types of these. Isoflavones, coumestans and a whole wide range of these kind of compounds. The key to these though in terms of thinking about mammary development is that they are fairly weak estrogens. So 1/1000 to 1/10,000 times as potent as estradiol 17Beta. Again estradiol 17Beta being like the most potent type of estrogen in terms of the kinds of functions that we're talking about. So they're fairly weak. They also preferentially bind beta estrogen receptors, versus the alpha receptors, so it depends which tissue you're talking about. A wide range of kinds of things will come into play as to whether these are actually having an impact on the mammary tissue. Let's go to the next slide. So as we think about this because they are coming from plants, again a wide range of, these are found in a wide range of plants species especially legumes. So beans, soybeans, alfalfa, clover, things like that, a lot of those kinds of types of agronomic crops that we use for animals. But they're also found in grasses. Fruits, just a wide range of plant species have some sort of estrogenic or potentially have some sort of estrogenic activity. Components that have estrogenic activity. Plant strains. Different kinds of strains of plants may have more or less. Growing conditions can impact the concentration of phytoestrogens in the plant. The quantity ingested obviously is going to impact potentially the animal. I call it animal metabolism here because a lot of these things, once they're ingested, they circulate through the body they're actually converted into metabolized into and some other component which may be more or less active. So it's not just in the plant but also helps metabolize an animal may impact that. Ratios a different kinds of plants have several different phytoestrogens so what's the ratio is a different ones and how the biological activity. And then tissue sensitivity that gets back to the burning to the beta receptor versus alpha receptor. A wild wide range of this kind of things. the key to this though is again they are fairly their potency are very low compared to estrodial. And so what a lot of times we find is, that the amount of estrogen, estradiol in the animal is high enough that it really overshadows, it doesn't allow these things to have an impact, particularly on the mammary gland. We can find such situations where it does have an impact, and certainly the original observations of these, the original characterization of phytoestrogens. Done in Australia back in the 1940s where they were grazing sheep on something called subterranean clover. And the sheep were grazing. This is basically all they were eating and over a period of time it had very high levels of phytoestrogens. They realized not only the animals were infertile, they had a lot of reproductive issues. Well they also started developing mammary glands even though they were not pregnant. That's a situation were we're getting very very high levels of phytoestrogren over a period of time and causing development of the mammary gland. Let's go to the next slide. But a lot of the times what we find is that experimentally, the way we can characterize these phytoestrogens is through taking out the internal source of estrogen. So ovariectomized. So this is an example of the effects of genistein. Genistein is the major phytoestrogen in say soybeans and ovariectomized gilts, see we're looking at the uterine horns here, not the mammary gland. Take a look at the uterus. This is an ovariectomized animal. So pretty much be like an animal that you'd see prior to puberty. This is estrogen treated, okay? Not genistein treated, this is estrogen treated. And you can see the massive growth of the two uterine horns here. Again these gilts compared to the non-treated and genistein treated would be kind of in between. In terms of the, I didn't have a picture of the genistein ones here but it kind of be in between here, but clearly much bigger than, much more developed. So then the ovariectomized one without anything without any estrogen or genistein. The key is that the uterus of the pig is extremely sensitive to estrogen. So that's why you get the massive growth of the uterine horns here. If we look at the mammary gland in these same kinds of animals, ovariectomized, we see the base of the nipple. The pink part is the, the stained is the kind of the collagenous tissue at the base of the nipple. The nipple would be up here. Genistein, really only see a little bit of development of lobules and LVI compared to when treated with estrogen, where we see a lot more of the lobules and LVI. The lobules being formed in this tissues, so again the genistein treatment, even at the level we were giving, was kind of in between. So it's estrogenic but you're not getting massive mammary gland development with the way this was done. This was only injected for 15 days or something like that. So clearly some tissues are much more reactive, responsive, than the mammary gland in this particular case. So that gives you just one example of thinking about vital estrogens. Very very effective in ovariectomized animal when we take out the internal source of estrogen. Again it just depends upon the animal depends upon so many circumstances as to whether it's going to have an impact on the mammary gland when the animal is intact and there's endogenous estrogen.
