How does stellate ganglion stimulation affect coronary blood flow during blockade with different beta-adrenoceptor antagonists?
Practolol differs from other beta-blockers by allowing coronary vasodilatation rather than vasoconstriction during stellate ganglion stimulation.
The β-adrenoceptor antagonists LB46, oxprenolol, K01366, propranolol, and practolol all decrease the myocardial demand for oxygen and increase efficiency; with the exception of practolol, they reduce coronary blood flow. Stellate ganglion stimulation causes coronary vasoconstriction after β-adrenoceptor blockade has been established with propranolol, LB46, oxprenolol, or K01366; in the presence of practolol it causes coronary vasodilatation.
Nayler et al. (Mon,) studied this question.