Effect of guanethidine

You are presented with responses to noradrenaline (5 nmole/kg), vasopressin (20 nmole/kg) and electrical stimulation (frequency 5 Hz; width 0.5 msec; voltage 6 V; duration 15 sec) of the sympathetic cardio-accelerator nerves. A response to guanethidine (2000 nmole/kg) is then presented and then, in the presence of guanethidine, responses to noradrenaline (5 nmole/kg), vasopressin (20 nmole/kg) and electrical stimulation of the sympathetic cardio-accelerator nerves again.

Tabulate the maximum changes in heart rate and mean blood pressure produced and the resting levels of these parameters before each response to the pressor drugs.