Effect of calculation stress on hemodynamics and plasma catecholamines before and after beta-blockade with propranolol (Inderal) and mepindolol sulfate (Corindolan).

The effect of calculation stress on hemodynamic parameters and plasma adrenalin and noradrenalin was studied in two groups of 6 male subjects, before and during beta-Blockade. One group received propranolol 15 mg i.v. and the other received mepindolol sulphate 0,5 mg i.v. There was an increase in heart rate, cardiac output and blood pressure during mental stress. A significant increase in plasma adrenalin but not in noradrenalin occurred at the same time. The stress-induced rise in HR but not that in blood pressure could be prevented by beta-receptor blockage with propranolol and mepindolol sulfate. The peripheral resistance (PR) and diastolic blood pressure in stress were even higher after propranolol than in the control study. Propranolol had no effect on the increased adrenalin concentration during stress, but it was prevented by mepindolol sulfate. There was no correlation between the increase in HR and that in adrenalin during stress, but the HR in stress and the HR reaction to infused isoproterenol were highly correlated.