ALTERATIONS TO THE ELECTROPHYSIOLOGY OF ISOLATED HUMAN DETRUSOR SMOOTH-MUSCLE CELLS IN BLADDER DISEASE

The aim of the study was to investigate the properties of the inward calcium current (i(Ca)) obtained from isolated human detrusor smooth muscle cells in different pathological conditions using the whole-cell patch-clamp technique. Previous experiments on field stimulated detrusor muscle strips have shown specific differences associated with hypertrophy and detrusor instability. As i(Ca) plays an important role in excitation-contraction coupling in this tissue, it was therefore of interest to determine if i(Ca) was altered in the above disease states. It was found that myocytes from patients with prostatic symptoms had a significantly increased surface area and that the kinetics of i(Ca) were also significantly altered in these cells. Although the surface area of cells from patients with idiopathic instability and detrusor hyperreflexia was also significantly increased, the kinetics of i(Ca) were altered in different ways. These alterations to i(Ca) will alter the action potential configuration and its propagation through the muscle mass.