Ion channel mechanism of regulatory volume decrease in rat ventricular myocytes

AIM: To observe the regulatory volume decrease (RVD) process of rat ventricular myocytes and to investigate its ion channel mechanism. METHODS: Isolated rat ventricular myocytes were exposed to hypotonic solution and the cell volume was measured using Coulter Counter System. RESULTS: Rat ventricular myocytes showed a RVD process and this process was blocked by Cl- channel blocker 9-AC and K+ channel blocker CsCl. Further results demonstrated that a subtype of the K+ channel involved in RVD was an ATP-sensitive K+ channel because of its high sensitivity to glibenclamide. CONCLUSION: The RVD process of rat ventricular myocytes is dependent on the parallel activation of Cl- channel and K+ channel. The subtype of K+ channel involved in the RVD process is ATP-sensitive K+ channel.