[MUSIC] Welcome, I want to continue thinking about and giving examples on talking about this idea of lactation in the absence of pregnancy. So again, just to remind you some definitions here, non-puerperal lactation. Lactation without giving birth. And again, encompasses a wide range of kinds of things that the mammary gland might undergo. And again, this idea of galactorrhea, abnormal or spontaneous flow of milk from the mammary gland, not associated with childbirth or nursing. And again, it's fairly prevalent in lactating women. Let's go to the next slide. So, we have in the previous video review very quickly, some of the factors that influence mammary growth, lactation and galactopoiesis. And this particular one, we're going to focus a lot on estrogen. And so we're really talking about estrogen, talking about how it's going to impact mammary gland growth. Recall, on the other hand, just to kind of add this to the bigger picture. Elevated estrogen often times results in elevated prolactin. And that feeds back in here, it also feeds back into lactogenesis and galactopoiesis. So estrogen is not directly impacting lactogenesis but indirectly through increasing prolactin. Let's go to the next slide. So to think about these kinds of things, we kind of need to think about, well, where is this estrogen coming from? So internally, it can be coming from the placenta. In many species, estrogen is very, very high during pregnancy. That's during pregnancy. So we can discount that one because we're talking about situations where the animal is not pregnant. And again, estrogen is very, very high coming from the placenta, From the ovary. And we have couple of situation a little bit abnormal, cystic ovaries and ovarian tumors. Let's go to the next slide. We'll think about the cystic ovaries for a moment. These are from bovine but typical concentrations or ranges in concentrations that you'd find in the cow during the follicular phase, so again just prior to ovulation. So we're talking about 10 to 50 picograms per milliliter. This typically lasts for a few, very few days, and then progesterone and this kind of animal is relatively low at that point. So although we might get a little bit of elongation of say the ducts in the mammary gland, the growing mammary gland, we're not going to get a lot of mammary gland development at that point. Pregnancy, on the other hand, again, is coming from the ovary and particularly the placenta. Very, very high concentrations for roughly 450 pg/mL over an extended period of time and it's also there at the same time that progesterone is very high. So again, that's really what's really driving that mammary gland development during pregnancy. Follicular cysts on the other hand and there's a variety of them, some of them will secrete some estrogen, a little bit high, not all that high in estrogen. But again, sometimes that can occur over an extended period of time. And sometimes, there's also increased progesterone. So yes, it can get a little bit of mammary gland growth in these cases. Let's go to the next slide. So cystic ovaries, may impact the mammary glands, more likely going to affect the other reproductive functions of the animal. Ovarian tumors, on the other hand, there are variety of types. Some of these are called sex cord-gonadal stromal tumors, and it's a group of different kinds of tumors that are derived from ovarian and as well as testis, testis stromal cells. In the case of the ovary, granulosa cells, thecal cells, and fibroblasts. And these can then secrete very, very high levels of estrogen. Go to the next slide. So, I'll give you a case study here just as an example of how this might be happening. This is a case of a Jersey heifer. An open heifer, 11 months old noticed with very, very large mammary gland, udder. In fact they could even strip out as much as a liter of milk out of the mammary gland. So clearly it had developed as well as come on through lactogenesis and had a lot of mammary secretion in there. A lot of times what happens in these situations with these abnormal lactation is people are concerned about the animal getting mastitis. And so antibiotic dry cow treatment was infused in this heifer to make sure she did not get mastitis and it wasn't being caused by mastitis. And I'll tell you, we're not being caused by mastitis, there were no other symptoms particularly noted. On the other hand, when they rectally palpated this heifer, they uterine horns were normal, the left ovary was pretty small but when they get to the right ovary and palpating that very large abdominal mass. Which has been dropped down here and it was ended up being an ovarian granulosa cell tumor. And I just want to show you this example here because estrogen levels in that animal were almost three times which you'd see in pregnancy. So very, very high levels of estrogen and again, over an extended period of time and even elevated progesterone there. So again, clearly this is a case where the animal is definitely not pregnant. But a lot of mammary gland development and release of the culprits that are sitting right here caused by this particular kind of tumor so just one example of that. [MUSIC]
