RESUMO
We studied the effects of carbon monoxide and sodium hydrosulfide, hydrogen sulfide donor, on contractile activity of the left ventricle in Langendorf-perfused isolated rat heart. Carbon monoxide 5×10(-5) M significantly accelerated sinus rhythm and left-ventricular pressure wave growth and decay. To the contrary, negative inotropic and chronotropic effects were observed at higher concentrations of carbon monoxide (10(-4), 3×10(-4) M). Sodium hydrosulfide (10(-4)-4×10(-4) M) decreased all the parameters of left-ventricular contractive activity and reduced contraction rate. Carbon monoxide and hydrogen sulfide, which together with nitrogen oxide are qualified as a new class of gaseous signal compounds, may substantially modulate pumping function of the heart.
