A, mean +s.e.m. of It (left) and Iss (right) in the absence of insulin (n= 42), after 5-9 h with 100 nM insulin (n= 35), and in the presence of 100 nM insulin and 2 μM cycloheximide (n= 24). Cycloheximide was added 1 h after insulin. *P < 0.05. B, cycloheximide (2 μM) alone (for 5-8 h, n= 14) has no effect on It (left), Iss (centre) and IK1 (right), in comparison to control (n= 16). Absolute values are given for IK1 here and in other figures.