Phone: (914) 594-4136
Department of Pharmacology
Basic Science Building, Rm. C27
15 Dana Road
Valhalla, NY 10595
Basic Science Research Interests:
Glandular kallikrein (GK) is a trypsin-like protease classically characterized by its ability to generate bioactive peptides (kinins) from large inactive precursor proteins (kininogens). Investigation of the potential role of GK in prohormone processing led to its discovery in the anterior pituitary where it is highly induced by estrogens and repressed by dopamine in lactotrophs - cells that secrete prolactin (PRL). A novel thiol-dependent processing reaction was discovered which enabled GK to cleave 3 highly conserved sites in the C-terminus of PRL to generate a large N-terminal fragment (174 a.a.), and 3 smaller peptides (11, 3, and 9 a.a.). The pituitary was found to secrete a novel estrogen- and thiol-dependent PRL product (PRL1-173) produced via serial processing by GK and carboxypeptidase E. The biological significance of this highly regulated and unusual processing remains a mystery.
Another research interest concerned the role of hormonal interplay with thyroid hormone in the integrative physiological mechanisms involved in the effects of estrogens and antiestrogens (such as tamoxifen) on energy balance, bone and lipid metabolism, growth and cardiovascular function in rat models relevant to human physiology and pathophysiology. The work indicates that estrogen and antiestrogen modulation of the actions and/or secretion of thyroid hormone, growth hormone (GH) and insulin-like growth factor I (IGF-I) contributes to estrogen and tamoxifen effects on a diverse subset of estrogen targets. Conversely, changes in the functional status of the thyroid or GH-IGF-I axis may alter the effects of estrogens and antiestrogens on such targets. The potential role of estrogen-related receptor-gamma in tamoxifen actions have also been an area of interest. The research may provide insights relevant to novel therapeutic uses for antiestrogens.
Educational Research Interests:
The relation of student attendance at voluntary class sessions is an area of interest of Dr. Powers. ‘Audience-response systems’ (ARS) are used in large classroom settings to provide students with the opportunity to actively engage with the material being presented in a stimulating manner that provides students with immediate feedback on their learning. Data collected in such sessions is being analyzed to examine the relation of class attendance to student performance, and the utility of such technology for enhancing student learning.