Control of skin blood flow is the result of influences from thermoregulatory reflexes (e.g., internal temperature, skin temperature) as well as from non-thermoregulatory reflexes (e.g., baroreceptor-mediated, exercise associated reflexes). These act through separate sympathetic vasoconstrictor and vasodilator systems, the influences of which are further modified by the temperature of the nerve-blood vessel junction (Tlocal in schematic). The laboratory group is seeking to understand the overall integration of these influences in humans by finding the reflexes that can modulate vasodilator activity and those that can modulate vasoconstrictor activity. We are also seeking to discover the mechanisms and transmitters through which the active vasodilator system functions and how local temperature further influences these controls.

Our current activities in these areas include research directed toward understanding changes in regulation of the cutaneous circulation that accompany the phases of the menstrual cycle and/or exogenous female steroid hormones. The laboratory is pursuing studies of alterations in control of the cutaneous circulation by the active vasodilator system and by the adrenergic vasoconstrictor system and how these changes are reflected in a modified thermoregulatory control of skin blood flow. We are also studying the potential influences of non-adrenergic transmitters co-released from sympathetic nerve terminals by local or reflex stimuli and how these co-transmitters affect the control of the cutaneous circulation in healthy humans.

Third, we are studying the integration of sensory and autonomic neural systems in the skin. We are examing how cold receptors and warm receptors are involved in the local control of the cutaneous circulation and the mechanisms for this involvement.