Inhalation anesthetics simultaneously cause vasoconstriction and vasodilation in different vascular beds. The long-term goal of this application is to elucidate molecular mechanisms of the anesthetic action on smooth muscles. Specifically this application will focus on the investigation of differential effect of the anesthetics on different arterial types at the organelle levels and its mechanisms of action. The study will test the hypothesis that differential effect of the anesthetics and its mechanisms of action depend on the arterial type by examining effects of the anesthetics on Ca2=-clamped skin arterial strips from different types of arteries measured with force development. The mechanisms of the differential action of the anesthetics will be investigated as follows. In skinned arterial strips monitored with force, to examine 1) whether the anesthetic-induced biphasic effect is by releasing Ca2+ specifically via the ryanodine-receptor SR Ca2= channel using ryanodine to block the channel, or nonspecifically via permeabilization of the SR membrane using Ca2= ionophore A23187 to deplete the Ca2= from the intracellular stores, and 2) whether the anesthetic effect is by activation of protein kinase C (PKC) or Ca2+/calmodulin-dependent protein kinase II (CaMKII), or both, using the specific inhibitors of the enzymes. In cultured cells and skinned arterial strips from the same arterial type, this research is to determine whether the anesthetic effect on PKC and CaMKii signalings is initiated by translocation of the enzymes, to downstream effectors including extracellular signal-regulated kinases and myosin light chain using fractionation. Immunohistochemisrty, and western blotting methods correlated with force development in skinned arterial strips. This grant application will provide information not onlyon mechanisms of anesthetic action but also will help in understanding the regulation and signaling pathways of PKC and CaMKII in vascular ssmooth muscle contraction. The understanding of the mechanisms of the anesthetic actions on smooth muscle contraction will enhance the safe and effective managementn of patients undergoing surgery, and aid in the design of more and effective and safer anesthetics. Further the understanding of signal pathways of CaMKII and PKC in smooth muscle will advance understanding mechanisms of agonist-activated force maintenance in smooth muscle, as well as cell motility and migration in non-muscle cells.
