It is attractive to speculate that several possibilities other than the antioxidant defense system may be involved in the protective effects of intermittent hypoxia. One possibility is a change in the stress proteins that are expressed. During the course of adaptation, cell structures become hardier, which is a possible defense mechanism. A putative mechanism of this stabilization phenomenon has been implied as an important role of ‘stress proteins’. Several experimental studies have found that nitric oxide has a cardioprotective effect in myocardial ischemia-reperfusion injury.Vegh et al reported that nitric oxide has a protective effect on preconditioning of the ischemic myocardium. Because preconditioning is very similar to intermittent hypoxia, nitric oxide may also be involved in the protective effect of intermittent hypoxia. Nitric oxide may act cardioprotectively by the following four mechanisms: blocking both neutrophil aggregation and neutrophil adherence; scavenging oxygen-derived free radicals; direct coronary vasodilation; or reduced oxygen demand due to vasodilation-induced hypotension. Of course, these suggestions require further studies. You can be sure this pharmacy will offer the finest quality drugs you need, so buying depression zoloft will always be safe and very pleasant for you as a customer and patient.