title: Physiological roles and properties of potassium channels in corporal smooth muscle.
abstract: Decreased penile vascular resistance induced by corporal smooth muscle relaxation is the most important step in penile erection. The heightened tone of the corporal smooth muscles is considered a major cause in impotence. Modulation of corporal smooth muscle tone is a complex process requiring the integration of a host of intracellular events and extracellular signals. In intracellular events of corporal smooth muscle cell, the potassium channels and calcium channels play a major role. Functionally, potassium channels are important regulators of smooth muscle membrane potential in response to depolarizing stimuli and they counteract calcium channels. Potassium channels have been shown to play a fundamental role in both the physiologic and pathophysiologic regulation of smooth muscle tone in diverse tissues. Among the several subtypes of potassium channels, the calcium-sensitive (K(Ca)) or maxi-K potassium channel subtypes are thought to be the most physiologically relevant in human corporal smooth muscle. Because of the physiological role of maxi-K channels in human corporal smooth muscles, we investigated the maxi-K channels for the genetic therapy of erectile dysfunction. These data indicate that naked hSlo DNA of maxi-K channels is quite easily incorporated into corporal smooth muscle and expression of the maxi-K hSlo cDNA appeared to be sustained for 1-4 months postinjection. These results show the possibility of a similar genetic strategy of potassium channels in humans.
authors.affiliation: Albert Einstein College of Medicine, New York, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Lee