Electromyographic Detection of Purinergic Activity in Guinea Pig Detrusor Smooth Muscle

Purpose: We recorded nerve mediated extracellular electrical activity from guinea pig detrusor smooth muscle strips using suction electrodes and determined the electrophysiological origins of this signal and its relationship to contractile activity.Materials and Methods: Mucosa-free detrusor strips were prepared from male guinea pigs sacrificed under Home Office license, physiologically superfused, attached to a pressure transducer and electrically stimulated (0.1 millisecond pulses). Electrical signals recorded using a bipolar reversible suction electrode were processed and recorded simultaneously with changes in strip tension. The effect of superfusion with α, β-methylene adenosine triphosphate (ATP), atropine, extracellular [CaCl2] depletion and pharmacological Ca2+ channel blockade on the electrical and mechanical signals was determined.Results: A biphasic electrical signal was consistently recorded from 37 detrusor strips. The signal was sensitive to graded reduction in [CaCl2] of the superfusate and...