A 72-year-old woman, who is being treated with propranolol, finds that she cannot maintain her previous exercise routine. Her physician explains that the drug has reduced her cardiac output. Blockade of which receptor is responsible for the decrease in cardiac output?

Question

Quizplus · Accepted Answer

[III 3; Table 3.1]. Propranolol is an adrenergic antagonist that blocks both $\beta_{1}$ and $\beta_{2}$ receptors. When propranolol is administered to reduce cardiac output, it inhibits $\beta_{1}$ receptors in the sinoatrial (SA) node (heart rate) and in ventricular muscle (contractility).

A 72-Year-Old Woman, Who Is Being Treated with Propranolol, Finds α1\alpha_{1}α1​

A 72-Year-Old Woman, Who Is Being Treated with Propranolol, Finds $\alpha_{1}$