Fig. 5. Anesthetic actions of propofol and 4-iodopropofol in mice and rats. (Left ) Dose–response curves for propofol (filled circles; n = 26) and 4-iodopropofol (open circles; n = 9) in producing loss of the righting reflex after intraperitoneal injection in adult C57BL/6 mice. (Right ) Dose–response curve for 4-iodopropofol (open circles) in producing loss of righting reflex after intravenous injection in adult Sprague-Dawley rats (n = 14). A dose of 10 mg/kg intravenous propofol produced anesthesia in 12 of 12 rats. For comparative purposes, the ED50of intravenous propofol for producing anesthesia in rats has been reported previously 38as 5.0 mg/kg.