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.
Hertel
R F
RF
Fraunhofer Institute of Toxicology and Aerosol Research, Hannover, Germany.
D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D004095:Dihydropyridines / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004431:Ear, External / Q000098:blood supply; D005260:Female; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011921:Rats, Inbred WKY; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012867:Skin / Q000098:blood supply*; D014665:Vasodilator Agents / Q000494:pharmacology*
D001578:Benzopyrans; D004095:Dihydropyridines; D015221:Potassium Channels; D014665:Vasodilator Agents; C061050:bimakalim