A Comparison of in Vivo and in Vitro Rates of Aging of Somaninhibited Erythrocyte Acetylcholinesterase in Different Animal Species

ABSTRACTThis study was conducted to assess differences in the rate of aging of soman-inhibited erythrocyte (RBC) acetylcholinesterase (Am) fm different species and to determine whether the rate of aging in vitro approximates that in vivo following a single exposure to soman. The logarithm of the percentage FU3C AChE reactivated by 2–PAM after soman exposure was plotted as a function of time. Linear regression analysis was used to determine the half-time (t1/2) for aglng. In the in vivo experiments, the rapidity of aging increased from rat to guinea pig to marmoset; the corresponding t1/2 values (mean ± standard error) were 8.6 (± 0.94) min, 7.5 (±1.7) min and 0.99 (± 0.10) min. The in vitro values of t1/2 in marmoset and guinea pig were 1.1 (± 0.08) min and 8.0 (± 0.82) rnin, respectively. Other t1/2 values computed for in vitro experiments were 1.4 (±0.11) rnin for cynomolgus monkeys and 0.88 (± 0.03) mln for squirrel monkeys. The results indicate that, for marmoset and guinea pig, the in vitro values cl...