Potassium channel activation improves blood flow pattern of conscious rats in cutaneous microcirculation

1. A dose-dependent mean arterial blood pressure reduction (tailcuff method) to an intravenously administered potassium channel activator (22 or 24 micrograms/kg bw) was found in conscious rats. 2. Intravital microscopic analysis of skin microcirculation in conscious rats was performed with respect to erythrocyte flow velocity and diameters of capillaries. There was a dose-dependent increase of erythrocyte flow velocity; diameters of capillaries were dilated following a dosage of 6 and 12 micrograms/kg bw, but constricted following a dosage of 24 micrograms/kg bw. 3. Frequency distributions of velocity ranges in capillaries under observation (real time video recordings) proved that the increase of microvascular perfusion is manifested by a shift of maximal values to increasing velocity ranges. 4. It is concluded that potassium channel activation plays an important role in the local regulation of perfusion on the peripheral circulation.