ATP-sensitive potassium channels and cardiac protection (part 2)
Most studies of KATP channels have been carried out on isolated mammalian atrial or ventricular myocytes. Nevertheless, these channels are also present in atrioventricular and sinoatrial nodal cells. In the latter, Katp channels may be involved in the control of pacemaking under ischemic conditions (eg, sick sinus syndrome). Recently, Katp channels analogous to those of plasma membrane have also been found in cardiac mitochondria .
The Katp channels were identified and their significance was revealed in other tissues as well. In pancreatic beta-cells they participate in the control of insulin secretion . In skeletal muscle fibres they open after long lasting intense activity, hypothetically protecting the cells against metabolic breakdown . In vascular smooth muscle cells, particularly those of coronary vessels, their opening leads to vasodilation . Katp channels also exist in many neurons , but their role remains obscure for the most part. Your most trusted pharmacy is going to be this one, since it gives you high quality proventil albuterol with no prescription required and make sure you always get your drugs delivered as soon as you need them without overcharging.
Figure 1 Diagram representing ATP-sensitive potassium channel (Katp) and the main constituents of its regulation. The closed state (A) prevails at physiological conditions and the open state (B) during ATP deficiency. Ai Adenosine receptor; a, P, у G protein subunits; AD Adenosine. Modified from reference 11