Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
Joshua Hurssey - Mississippi Valley State University
Hormones such as estrogen, leptin, and Neuropeptide Y (NPY) are known to influence body fat distribution and adipocyte differentiation. The aforementioned hormones are essential for regulating appetite and are responsible for energy balance. The changes in these hormones at menopause and their influence on increased body fat is not clear. Our aim was to characterize these three hormone levels and evaluate the characteristics of size and distribution of the fat in the bone marrow and subcutaneous tissue surrounding a sham, estrogen, or NPY-1 receptor antagonist tricalcium phosphate (TCP) drug delivery device. Forty female Sprague Dawley rats were divided into five equal groups. Animals in group 1 served as ovariectomized control, Animals in Groups 2-4 received a non-drug loaded TCP capsule (SHAM), or an implant containing 5 mg or either estrogen benzoate or a NPY-1Receptor antagonist for 4 weeks. Animals in Group 5 were naïve females with ovaries intact. Body weights, blood, and tissues were collected and the analysis of estrogen, leptin, NPY, and fat distribution was determined and compared to group 1 animals. Animals in the OVX and SHAM groups had body weights significantly higher than naïve control. Animals in the estrogen and NPY-1RA treated groups had body weights which were significantly lower than OVX and Sham animals but still higher than naïve control after 4 weeks. Serum levels of leptin and NPY were both elevated in OVX, Sham, and NPY-1RA animals and estrogen was barely detectable. Estrogen administration returned serum levels of NPY, leptin, and estrogen comparable to values obtained for naïve control animals. Estrogen had the most significant effects on the size and number of fat droplets in both the subcutaneous tissue and bone marrow when compared to the other treatment groups and the OVX and intact control animals. The size of the adipocyte was substantially smaller. The adipocytes in sham and OVX groups were larger than those seen in estrogen, and smaller than those obtained in NPY-1RA treated animals. NPY-1RA returned the size and distribution of the adipocytes to control intact values. Overall, estrogen possibly had effects at the adipocyte and HPA axis whereas, NPY-1RA had appeared to have direct effects on the adipocyte peripherally. Acknowledgement: This work was supported by the Mississippi INBRE, funded by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103476. Faculty Advisor/Mentor: Rachel Beecham, rvbeecham@yahoo.com
Joshua Hurssey - Research Abstract.docxFunder Acknowledgement(s): This work was supported by the Mississippi INBRE, funded by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103476.
Faculty Advisor: Rachel Beecham, rvbeecham@yahoo.com
Role: I conducted all of the research and made a plan to see it through with my project. I did most of the cell plating, slide staining, and monitoring the rats weight, leptin, estrogen, and NPY levels. Also, because the rats had to be ovariectomized, I watch the surveys conducted on the rats. I also collected all the measurements and data for my project.