Figure 1.

Mean ± SD values of oxygen uptake ($\dot{V}$O₂), CO₂ output ($\dot{V}$CO₂), and mean arterial blood pressure (ABP) in 8 sheep exposed to a lethal level of H₂S (protocol 1). Left panels (closed symbols) display the time course of the effects of H₂S alone, whereas the right panels (open symbols) show the effects of H₂S along with MB. The red-doted lines in the right panels correspond to the average data of the untreated animals shown here for comparison. MB increased $\dot{V}$O₂ and $\dot{V}$CO₂, which remained above the levels in nontreated animals during the entire period of exposure to sulfide. Note that (1) $\dot{V}$O₂ and $\dot{V}$CO₂ were still above 100 ml/min at a time when all of the nontreated animals were dead, (2) blood pressure was maintained around baseline levels even when the cardiac function was very much depressed suggesting that a significant peripheral vasoconstriction occurred.