Using an in vitro perfusion method, we examined the effects of cromakalim, a potassium channel opener, on the superior cerebellar arteries of 24 rats. Cromakalim had no effect on contractions induced by 129 mM K+ until a concentration of 10-5 M was reached. Contractions evoked by 10-5 M serotonin were attenuated by cromakalim in a con centrat ion-dependent manner (p <0.05). The diameter of untreated superior cerebellar arteries remained almost constant with increasing perfusion pressure. However, in the presence of cromakalim, vessel diameter increased with increasing perfusion pressure. At concentrations of 3×10-6 M, cromakalim also inhibited basal myogenic tone and dilated unstimulated arteries (p <0.01). These results suggest that cromakalim is a cerebrovascular dilator acting on both receptor-mediated and myogenic contractions.
All Science Journal Classification (ASJC) codes
- Clinical Neurology
- Cardiology and Cardiovascular Medicine
- Advanced and Specialised Nursing