Abstract
Norepinephrine (NE) dose-response curves in the contractile force and its max dF/dt were examined in the papillary muscle of the right ventricle of the cat under pretreatment with pancuronium bromide (PB), 3 X 10-5M. and vecuronium bromide (VB), 3 X 10-5M., 10-7M..
The dose-response curves with PB pretreatment were shifted leftward significantly as compared with the control group. The curves under pretreatment with VB were also moved to the left the same as those with PB pretreatment.
It is likely that the shift to the left by pretreatment with PB may be due to the inhibition of NE uptake 1 and that by pretreatment with VB to the inhibition of NE uptake 2.
