BK channels oppose vasoconstriction in blood vessels resulting in vasorelaxation. Blocking the channels leads to vasoconstriction and to an increase in blood pressure. The BK channel α subunit is expressed in muscle and nerve tissue and the BK channels are abundant in the brain. The BK channels modulate neurotransmitter release, the form of the action potential and repetitive firing. Inhibition of the channels can explain why there would be an increased release in excitatory neurotransmitters resulting in tremors, ataxia, hypersensitivity, increased smooth muscle contraction in the colon and an increased heart rate.
