Scintillation counter

该应用程序是一种新的闪烁计数器，这是一种测量生物组织或其他材料的小样本中的放射性的机器。我们需要这个来取代我们在1984年购买的一个老化的计数器，它现在的灵敏度非常低，并且有多种机械问题。我们正在使用它来追踪个体之间的氚化（3 H-）类固醇。我们正在研究类固醇激素，如雌二醇，最强大的雌激素，不仅作用于个体，而且在个体之间传递的可能性。我们已经发现雌二醇和其他小类固醇是由成年雄性小鼠和其他哺乳动物分泌的。这与两种众所周知的信息素效应有关：1）与不熟悉的成年男性接触引起的女性怀孕损失，以及2）暴露于不熟悉的成年男性的青少年女性的青春期提前。这两种效应都可以通过给雌性注射雌二醇来模拟。我们正在用小鼠进行实验，我们从雄性的尿液和其他排泄物中追踪3 H-雌二醇，然后测量附近雌性的子宫和大脑中的3 H-雌二醇。这是非常有意义的，因为有证据表明子宫内雌二醇的小幅升高会干扰早期妊娠。此外，雌二醇促进青春期，因为子宫的生长是由雌二醇自然驱动的，女性的性行为是由雌二醇在大脑下丘脑中的作用自然刺激的。因此，这种新的闪烁计数器是我们的研究确定重要的生殖信息素的化学性质的关键。一个新的闪烁计数器也将有助于这个实验室的能力，测量类固醇在血液，尿液和其他媒体，因为它将允许我们使用敏感的放射免疫测定程序。该计数器对于已经在实验室中的学生的研究的继续是至关重要的，它将帮助未来的学生在信息素动力学和内分泌干扰方面进行创新研究。这将有助于确保该实验室保持竞争力，为基础生殖科学和生殖毒理学做出重大贡献。

This application is for a new scintillation counter, which is a machine that measures radioactivity in small samples of biological tissues or other materials. We need this to replace an aging counter that we purchased in 1984, which now has very reduced sensitivity and multiple mechanical problems. We are using this to trace tritiated (3H-) steroids between individuals. We are examining the possibility that steroid hormones such as estradiol, the most powerful estrogen, not only act within individuals but also pass between individuals. We have found that estradiol and other small steroids are excreted by adult male mice and other mammals. This is associated with two well-known pheromonal effects: 1) the loss of pregnancy in females caused by contact with unfamiliar adult males, and 2) early puberty in juvenile females exposed to unfamiliar adult males. These effects can both be mimicked by injecting females with estradiol. We are conducting experiments with mice where we trace 3H-estradiol from males' systems into their urine and other excretions, then measure this 3H-estradiol in the uterus and brain of nearby females. This is very meaningful given evidence that small elevations of estradiol in the uterus can disturb early pregnancy. Furthermore, estradiol promotes puberty, as growth of the uterus is naturally driven by estradiol and female sexual behaviour is naturally stimulated by the actions of estradiol in the hypothalamus of the brain. Accordingly, this new scintillation counter is critical for our research identifying the chemical nature of important reproductive pheromones. A new scintillation counter will also help this laboratory's ability to measure steroids in blood, urine, and other media, as it will allow us to use sensitive radioimmunoassay procedures. This counter is critical for the continuation of the research of students already in the laboratory, and it will help future students to conduct innovative research in pheromone dynamics and endocrine disruption. It will help to ensure that this laboratory remains competitive, making substantial contributions to basic reproductive science and reproductive toxicology.