The role of glycerylphosphorylcholine and glycerylphosphorylethanolamine in liver phospholipid metabolism

CHOLINESTERASES 5 cannot protect at or below 0 1 mm, and a single observation on adrenochrome, kindly given us by Dr Harley-Mason, shows that it is without protective effect. It is well known to pharmacologists that the concentration of adrenaline in tissues is seldom above 1 g./g. (about 5 pM) and is often nearer 1 ,ug./kg. (5 ,umM). Thus it seems extremely unlikely that mobilization of adrenaline could influence the inhibition of cholinesterase in vivo. SUMMARY 1. The effect of sixteen amino acids on the inhibition of horse-serum cholinesterase by Sarin (i8opropyl P-methylphosphonofluoridate) was ex- amined. Only dopa (3:4-dihydroxyphenylalanine) was able, in high concentration, to abolish the inhibition in vitro.