Willis K. Samson

Ph.D. Physiology, University of Texas Southwestern Medical School 1979

Department: Pharmacological & Physiological Science

Academic Rank: Professor

Phone: 314-977-8677 Fax: 314-977-8670

E-mail: samsonwk@slu.edu

Lab Web Page Links:


Primary Area of Cardiovascular Research Interest

-Neuropeptides and the control of cardiovascular function and stress hormone secretion

Related Areas of Cardiovascular Research Interest

-Discovery of novel peptide hormones and characterization of their cognate receptors in cardiovascular and autonomic tissues

Summary of Cardiovascular Research Interest

We study the roles played by vasoactive peptides in the co-ordinated regulation of cardiovascular homeostasis. Cardiovascular homeostasis (health) is maintained by hormonal and neuronal mechanisms all integrated to assure adequate cardiac function. This requires communication among numerous tissues (e.g. blood vessels, kidneys, adrenal glands, brain and the heart itself) and it has become clear that these organ systems are not only interconnected via nerves, but also that a blood borne system of messengers (i.e. hormones) acts to also co-ordinate their function. These hormones are actually small proteins that are produced in many tissues, most notably the blood vessels themselves, the heart and even the brain where they function as neurotransmitters.

Our particular focus is how these vasoactive peptides act in brain (as neurotransmitters) and in the anterior pituitary gland (controlling the release of classical hormones) so that cardiovascular and renal function is maintained. In particular we are interested in how our bodies regulate fluid and electrolyte intake and excretion. Volume status and plasma osmolality are factors that can seriously compromise cardiac function. We study how these small peptides act in brain to control salt and water intake and how they modify autonomic nervous system function (which then controls blood pressure). Currently we are studying the actions of three classes of known peptides in brain and pituitary gland: the adrenomedullins, the hypocretins/orexins, and the recently described prolactin releasing peptides. We are also characterizing two recently discovered peptide hormones, nesfatin (discovered by M. Mori) and neuronostatin (discovered by our lab) in terms of their CNS and direct cardiac actions to control circulatory function. What these peptides have in common is the ability to alter cardiac performance by actions in brain. We study those actions of these peptides in vivo and in tissue culture system in vitro, employing both classical pharmacologic approaches and more modern molecular technologies. Our long term goals are to understand the relevance of the actions of these peptides in brain and heart and to establish the potential for their use in clinical settings.