Meredith Hay
Professor, BIO5 Institute
Professor, Evelyn F Mcknight Brain Institute
Professor, Physiology
Professor, Psychology
Professor, Physiological Sciences - GIDP
Primary Department
Department Affiliations
(520) 626-7384
Work Summary
Our lab is focused on the development of novel peptides to inhibit this inflammatory cascade and improve brain blood flow. These peptides are designed to significantly improve serum half-life and penetrate the blood-brain-barrier. These peptides act to inhibit the inflammatory pathways at both the level of brain blood vessels and the brain itself.
Research Interest
Dr. Hay is internationally known for her work in cardiovascular neurobiology and her current studies on the role of sex and sex hormones in the development of hypertension. She has been continuously funded by the NIH and other sources for the past 26 years. She has extensive experience in central renin angiotensin mechanisms, neurophysiology and reactive oxygen and cytosolic calcium neuroimaging and in advancing knowledge related to central mechanisms of neurohumoral control of the circulation. She is a Professor of Physiology at the University of Arizona College of Medicine and maintains active participation in the American Physiological Society, the Society of Neuroscience, AAAS, and has served on numerous editorial boards of prestigious scientific journals and grant review panels for the National Institutes of Health and the National American Heart Association. The primary focus of Dr. Hay’s laboratory is the understanding of the biophysical and cellular mechanisms underlying neurotransmitter modulation of sympathetic outflow and ultimately arterial blood pressure. The scientific questions being asked are: 1) What central neurotransmitter mechanisms are involved in the normal regulation of cardiovascular function? 2) Does the development of some forms of hypertension involve biophysical or molecular alteration in the neurotransmitter mechanisms regulating cardiovascular control? 3) Can these central signal transduction systems, which control sympathetic outflow and ultimately arterial blood pressure, be altered in order to prevent or attenuate the development of some forms of hypertension? 4) Are there gender related differences in some of these mechanisms?Dr. Hay has extensive national experience in university-wide administration and interdisciplinary research program development. Prior to coming to the University of Arizona in 2008 as Executive Vice President and Provost, Dr. Hay was the Vice President for Research for the University of Iowa, where she worked with state and federal lawmakers, private sector representatives, and local community groups to broaden both private and public support for research universities. Dr. Hay, a Texas native, earned her B.A. in psychology from the University of Colorado, Denver, her M.S. in neurobiology from the University of Texas at San Antonio, and her Ph.D. in cardiovascular pharmacology from the University of Texas Health Sciences Center, San Antonio. She trained as a postdoctoral fellow in the Cardiovascular Center at the University of Iowa College of Medicine and in the Department of Molecular Physiology and Biophysics at Baylor College of Medicine in Houston. She was a tenured faculty member of the University of Missouri-Columbia from 1996-2005. Prior to Missouri, she was a faculty member in the Department of Physiology at the University of Texas Health Science Center- San Antonio.


Hay, M., Vanderah, T. W., Samareh-Jahani, F., Constantopoulos, E., Uprety, A. J., & Barnes, C. A. (2017). Cognitive impairment in heart failure: A protective role for Angiotensin-(1-7). Behavioral Neuroscience, 131, 99-114.
BIO5 Collaborators
Carol A Barnes, Meredith Hay
Pollow, D. P., Uhrlaub, J., Romero-Aleshire, M. J., Sandberg, K., Nikolich-Zugich, J., Brooks, H. L., & Hay, M. (2014). Sex differences in T-lymphocyte tissue infiltration and development of angiotensin II hypertension. Hypertension, 64(2), 384-90.
BIO5 Collaborators
Heddwen L Brooks, Meredith Hay

There is extensive evidence that activation of the immune system is both necessary and required for the development of angiotensin II (Ang II)-induced hypertension in males. The purpose of this study was to determine whether sex differences exist in the ability of the adaptive immune system to induce Ang II-dependent hypertension and whether central and renal T-cell infiltration during Ang II-induced hypertension is sex dependent. Recombinant activating gene-1 (Rag-1)(-/-) mice, lacking both T and B cells, were used. Male and female Rag-1(-/-) mice received adoptive transfer of male CD3(+) T cells 3 weeks before 14-day Ang II infusion (490 ng/kg per minute). Blood pressure was monitored via tail cuff. In the absence of T cells, systolic blood pressure responses to Ang II were similar between sexes (Δ22.1 mm Hg males versus Δ18 mm : Hg females). After adoptive transfer of male T cells, Ang II significantly increased systolic blood pressure in males (Δ37.7 mm : Hg; P

Hay, M., McKenzie, H., Lindsley, K., Dietz, N., Bradley, S. R., Conn, P. J., & Hasser, E. M. (1999). Heterogeneity of metabotropic glutamate receptors in autonomic cell groups of the medulla oblongata of the rat. The Journal of comparative neurology, 403(4), 486-501.

Metabotropic glutamate receptors (mGluRs) in the medulla oblongata have been suggested to be involved in the regulation of autonomic function. The aim of the present study was to examine the localization and expression of four types of mGluRs: mGluRla, mGluR2/3, mGluR5, and mGluR7 in the dorsal and ventral autonomic nuclei of the medulla of the rat. The four mGluR subtypes studied were differentially distributed in distinct subnuclei in the nucleus of the solitary tract (NTS). mGluRla immunoreactivity was identified in cell bodies, dendrites, and axonal processes in the intermediate, dorsal lateral, and interstitial subnuclei of the NTS. No mGluRla immunoreactivity was observed in the commissural or medial NTS subnuclei. Immunoreactivity for mGluR2/3 and mGluR5 as observed in fibers and putative axonal processes in the interstitial, intermediate, and dorsolateral subnuclei of the NTS. In contrast, mGluR7 was expressed primarily in fibers and terminals in the central and commissural NTS subnuclei. Expression of mGluR2/3 was clearly evident in cell bodies, dendrites, and axonal processes within the area postrema. The vagal outflow nuclei were also studied. The dorsal motor nucleus of the vagus (DMN) contained mGluRla cell bodies, dendrites, and axonal fibers and light mGluR2/3 processes. Throughout the rostral-caudal extent of the compact and semicompact formation nucleus ambiguus, mGluRla was found in cell bodies and fibers. Within the caudal and rostral regions of the ventral lateral medulla, mGluRla was observed in cell bodies and fibers. Cell bodies containing mGluRla were found adjacent to cells staining positive for tyrosine hydroxylase (TH) in these regions but were not colocalized with the TH staining. However, mGluRla-expressing neurons in the ventral lateral medulla did appear to receive innervation from TH-containing fibers. These results suggest that the mGluRla-expressing neurons within the ventral lateral medulla are predominantly not catecholaminergic but may be innervated by catecholamine-containing fibers. These data are the first to provide a mapping of the different mGluR subtypes within the medulla and may facilitate predictions regarding the function of L-glutamate neurotransmission in these regions.

Xue, B., Johnson, A. K., & Hay, M. (2013). Sex differences in angiotensin II- and aldosterone-induced hypertension: the central protective effects of estrogen. American journal of physiology. Regulatory, integrative and comparative physiology, 305(5), R459-63.

Premenopausal women have lower blood pressure and a reduced incidence of cardiovascular disease compared with age-matched men. Similar sex differences have been seen across species and in multiple animal models of hypertension. While important progress over the last decade has been made in elucidating some of the mechanisms underlying these differences, there are still significant gaps in our knowledge. Understanding the cellular and molecular mechanisms responsible for sex differences in hypertension will be important for developing sex-specific therapies targeted toward the prevention and treatment of hypertension. Female sex hormones, especially estrogen, have been demonstrated to modulate the renin-angiotensin-aldosterone system (RAAS) and to have beneficial effects on cardiovascular function through actions not only on the kidney, heart, and vasculature, but also on the central nervous system (CNS). This review primarily focuses on the central regulatory actions of estrogen on brain nuclei involved in blood pressure regulation and the interactions between estrogen and the RAAS in the CNS by which estrogen plays an important protective role against the development of hypertension.

Foley, C. M., Vogl, H. W., Mueller, P. J., Hay, M., & Hasser, E. M. (1999). Cardiovascular response to group I metabotropic glutamate receptor activation in NTS. The American journal of physiology, 276(5 Pt 2), R1469-78.

Glutamate is the proposed neurotransmitter of baroreceptor afferents at the level of the nucleus tractus solitarius (NTS). Exogenous glutamate in the NTS activates neurons through ionotropic and metabotropic glutamate receptors (mGluRs). This study tested the hypothesis that group I mGluRs in the NTS produce depressor, bradycardic, and sympathoinhibitory responses. In urethan-anesthetized rats, unilateral 30-nl microinjections of the group I-selective mGluR agonist 3,5-dihydroxyphenylglycine (DHPG) into the NTS decreased mean arterial pressure, heart rate, and lumbar sympathetic nerve activity. The dose of drug that produced 50% of the maximal response (ED50) was 50-100 microM. The response to microinjection of equal concentrations of DHPG or the general mGluR agonist 1-aminocyclopentane-1S,3R-dicarboxylic acid (ACPD) produced similar cardiovascular effects. The cardiovascular response to injection of DHPG or ACPD was abolished by NTS blockade of mGluRs with alpha-methyl-4-carboxyphenylglycine (MCPG). Blockade of ionotropic glutamate receptors with kynurenic acid did not attenuate the response to DHPG or ACPD injection. These data suggest that DHPG and ACPD activate mGluRs in the NTS and do not require ionotropic glutamate receptors to produce their cardiovascular response. In the NTS the group I mGluRs produce responses that are consistent with excitation of neurons involved in reducing sympathetic outflow, heart rate, and arterial pressure.