Participation of nitric oxide in regional coronary bloodflow regulation during myocardial ischemia in the canine heart (part 13)

12 Sep

Furthermore, although the release of nitric oxide through a signal from the ischemic myocardium may also explain part of the vasodilation observed during reactive hyperemia , it is well known that the increase in flow during reactive hyperemia is in excess of the oxygen debt established during the occlusion, as revealed by the persistence of flow and venous coronary oxygen content above control values after the oxygen debt has been paid . This means another stimulus for nitric oxide production in a nonregulatory manner.Because about 40% of this overpayment of flow can be abolished with NONLA , it is very probable that at least part of the overpayment is due to the release of nitric oxide by the sudden increase in shear stress immediately after release of coronary occlusion. These results and considerations suggest that the participation of nitric oxide during reactive hyperemia is mediated not only by ischemia but also by the particular hemodynamics of this phenomenon, mainly the reperfusion.

Therefore the changes in flow produced by inhibition of nitric oxide synthesis during reactive hyperemia do not properly indicate the release of nitric oxide by ischemia. You will always find the required amount of Purchase Cheap Claritin at the pharmacy that will be happy to take best care of you by offering safe possibility to purchase the drugs you need without any need to get a prescription first or take any other extra steps. In conclusion, our results support the idea that nitric oxide is an important mediator in the coronary vasodilatory response and in the distribution of flow towards the subendocardium during myocardial ischemia. It is then reasonable to expect that endothelial damage produced by different pathological conditions with a decrease in the ability to produce nitric oxide, such as hypertension and heart failure , may impair the regulation of coronary flow during myocardial ischemia.