Microvascular Research Laboratory
Lacy Alexander, Ph. D.
Research Assistant Professor of Kinesiology
Dr. Alexander’s research utilizes the human cutaneous circulation to examine the underlying signaling mechanisms mediating microvascular dysfunction in diseases such as essential hypertension, Reynaud’s disease, and hypercholesterolemia, and the influence of drug-interventions such as the effect of commonly-used platelet inhibitors on platelet-vessel wall interactions.
Overview of Primary Research:
Hypertension and Skin Blood Flow: Hypertension-induced vascular dysfunction including impaired endothelial function and inward vessel remodeling are detectable in human skin. Current studies pair in vivo and in vitro methods to examine the putative link between inflammation, endothelial dysfunction, and inward vessel wall remodeling with essential hypertension through arginase signaling.
High Cholesterol and Skin Blood Flow: Elevated concentrations of low density lipoproteins are highly atherogenic and independently associated with the severity of coronary atherosclerosis. One early indicator of hypercholesterolemic-associated vascular disease is a decrease in endothelial derived nitric oxide (NO). In this series of studies we are examining the underlying mechanisms mediating hypercholesterolemic vascular dysfunction in the cutaneous microcirculation. We are further examining the effects of the most commonly prescribed cholesterol lowering therapy on mechanisms meditating microvascular reactivity in human skin. Drs. Lacy Alexanderz and W. Larry Kenney collaborate on this project.
Platelet Inhibition and Skin Blood Flow: Low-dose aspirin (ASA) therapy is utilized clinically in healthy populations to inhibit cyclooxygenase-1 (COX-1) in platelets for atherothrombotic prevention, however, chronic COX-inhibition with low-dose aspirin consistently and significantly attenuates reflex cutaneous vasodilation. Our ongoing studies are examining the potential roles of 1) platelet activation, and alterations in blood viscoelastic properties on shear-induced vasodilation and 2) the functional consequences of platelet inhibitor-induced attenuation in skin blood flow during exercise in the heat. Drs. Lacy Alexander and W. Larry Kenney collaborate on this project.
Raynaud’s Disease: The cutaneous vascular dysfunction that is characteristic of Raynaud’s can cause severe constriction that is most often evident in the skin of the hands and feet. The constriction can result in dramatically reduced blood flow, ischemia, and even tissue-death. The color of the affected skin can range from white to blue during an attack and is often accompanied by numbness and, later, throbbing, redness, and pain upon rewarming. We explore the mechanisms and possible interventions for the hyper-reactivity and constriction of cutaneous blood vessels that occurs when Raynaud’s-sufferers are exposed to cold and/or emotional stressors.
(L to R Back:) Susan Beyerle, Lacy Alexander, and Caroline Smith
(L to R Front): Sue Slimak, Jessie Kutz, Jane Pierzga, Anna Stanhewicz,
W. Larry Kenney, and Rebecca Bruning
Post Doctoral Fellow: Caroline Smith, Ph. D.
Assistants: Jane Pierzga, M.S. – Faculty Research Assistant
Susan Slimak, R.N. – Research Nurse
Graduate Students: Rebecca Bruning
- Essential Hypertension and Skin Blood Flow (NIH) R01 HL093238-01
- Hypercholesterolemia and Human Skin Blood Flow (NIH) R01 HL089302
- Low-Dose Aspirin and Human Skin Blood Flow (NIH) R21 HL098645