University of Louisville
Effects of Estrogenic Action in the Aging Lung
Institution
University of Louisville
Faculty Advisor/ Mentor
Cynthia Corbitt; Andrew Roberts
Abstract
Women experiencing severe menopause symptoms (e.g. hot flashes, vaginal dryness, and osteoporosis) might use hormone replacement therapy (HRT) to reduce these side effects, but some women seek what they consider more “natural” alternatives to HRT, such as phytoestrogens. These are plant-produced estrogen receptor agonists that are available over the counter, but currently are not regulated by the FDA. Phytoestrogens are also found in soy-based foods. This study investigated the effects of estrogenic activity on lung structure and compliance in a rodent model of menopausal women. Previous studies found that estrogen modifies lung morphology. To date, there are no published studies on the effects of phytoestrogens on static lung compliance or the ratio of collagen and elastin which affects lung tissue elasticity and stiffness. For this study we used 21 female retired breeder Sprague-Dawley rats that were randomly assigned to four different groups: sham control (no ovariectomy, soy-free food), estrogen (ovariectomy + estrogen replacement, soy-free food), phytoestrogen (ovariectomy, soy food), and negative control (ovariectomy, soy-free food). Here we report that neither estrogen nor supplement of phytoestrogens through a diet rich in soy gave the protective effects that we predicted in a measure of static lung compliance or in an assay of lung elastin content. The presence of these phytoestrogens did, however, slow the rate at which rats gained weight after ovariectomy when estrogen was not replaced. It is important to note that some other extracellular matrix component might account for the previously seen effects of estrogen on lung morphology and function.
Effects of Estrogenic Action in the Aging Lung
Women experiencing severe menopause symptoms (e.g. hot flashes, vaginal dryness, and osteoporosis) might use hormone replacement therapy (HRT) to reduce these side effects, but some women seek what they consider more “natural” alternatives to HRT, such as phytoestrogens. These are plant-produced estrogen receptor agonists that are available over the counter, but currently are not regulated by the FDA. Phytoestrogens are also found in soy-based foods. This study investigated the effects of estrogenic activity on lung structure and compliance in a rodent model of menopausal women. Previous studies found that estrogen modifies lung morphology. To date, there are no published studies on the effects of phytoestrogens on static lung compliance or the ratio of collagen and elastin which affects lung tissue elasticity and stiffness. For this study we used 21 female retired breeder Sprague-Dawley rats that were randomly assigned to four different groups: sham control (no ovariectomy, soy-free food), estrogen (ovariectomy + estrogen replacement, soy-free food), phytoestrogen (ovariectomy, soy food), and negative control (ovariectomy, soy-free food). Here we report that neither estrogen nor supplement of phytoestrogens through a diet rich in soy gave the protective effects that we predicted in a measure of static lung compliance or in an assay of lung elastin content. The presence of these phytoestrogens did, however, slow the rate at which rats gained weight after ovariectomy when estrogen was not replaced. It is important to note that some other extracellular matrix component might account for the previously seen effects of estrogen on lung morphology and function.