pharmacy
The principal mechanism of phentolamine-induced tachycardia is:
a) Antagonism of presynaptic alfa2 receptors enhances norepinephrine release, which causes cardiac stimulation via unblocked beta receptors
b) Baroreflex mechanism
c) Direct effect on the heart by stimulation of beta1 receptors
d) Inhibition of transmitter reuptake at noradrenergic synapses
A
A