Potassium Channels and Muscle Relaxation in the Penis: How Diabetes Affects Relaxation by ATP-Sensitive Potassium Channel Openers

A total of 215 isolated human corporeal tissue strips from 57 male patients were investigated for relaxation responses to K channel modulators.

• Pinacidil and levcromakalim produced a concentration-dependent relaxation in phenylephrine pre-contracted corporeal tissue strips.
• The relaxation response was sensitive to glibenclamide, indicating involvement of adenosine triphosphate sensitive K channels.
• Tissue strips from patients without diabetes showed greater sensitivity to relaxation by both compounds compared to those with diabetes.
• Electrophysiological recordings demonstrated that both K channel modulators induced potassium currents that were blocked by glibenclamide.
• Relaxation responses were unaffected by charybdotoxin or 4-aminopyridine but reversed by KCl or tetraethylammonium chloride.

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