Cutaneous control of blood pressure #MMPMID26625865
Johnson RS; Titze J; Weller R
Curr Opin Nephrol Hypertens 2016[Jan]; 25 (1): 11-5 PMID26625865show ga
Purpose of review: Textbook theory holds that blood pressure is regulated by the brain, by blood vessels, or by the kidney. Recent evidence suggests that blood pressure could be regulated in the skin. Recent findings: The skin holds a complex capillary counter current system which controls body temperature, skin perfusion, and apparently systemic blood pressure. Epidemiological data suggest that sunlight exposure plays a role in controlling blood pressure. UVA radiation produces vasodilation and a fall in blood pressure. Keratinocytes and immune cells control blood flow in the extensive countercurrent loop system of the skin by producing NO, a key regulator of vascular tone. The balance between HIF-1? and HIF-2? activity in keratinocytes controls skin perfusion, systemic thermoregulation, and systemic blood pressure by NO-dependent mechanisms. Furthermore, the skin accumulates Na+ which generates a barrier to promote immunological host defense. Immune cells control skin Na+ metabolism and the clearance of Na+ via the lymphatic system. Reduced lymphatic clearance increases blood pressure. Summary: Besides the well-known role of the brain, blood vessels, and the kidney, the skin is important for systemic blood pressure control in humans and in experimental animals.