Effects of hydrogen peroxide on contraction of skinned aorta from guinea pigs.

We examined the effects of hydrogen peroxide (H2O2) on the contractile force of cell membrane permeabilized descending thoracic aorta from guinea pigs. H2O2 enhanced generated force in the Ca2+-induced contraction at any given concentration of Ca2+, and maintained force level in the 30 mM Mg2+-induced Ca2+-independent force maintenance. H2O2 seems to directly enhance the cross-bridge interaction of aortic smooth muscles.