Fig. 4. Loss-of-righting reflexes (LORR) in rats. (A ) Cyclopropyl-methoxycarbonyl metomidate and methoxycarbonyl metomidate dose-response curves for LORR. Each point represents data obtained from a single rat experiment. The curves are fits of each data set using the method of Waud, yielding ED50s of 0.69 ± 0.04 mg/kg for cyclopropyl-methoxycarbonyl metomidate and 11.1 ± 0.8 mg/kg for methoxycarbonyl metomidate. (B ) For representative spacer-linked etomidate esters, a semilogarithmic plot of the duration of LORR as a function of dose. Each point represents data obtained from a single rat experiment.