Final answer:
Beta blockers inhibit beta-adrenergic receptors, while ACE inhibitors inhibit angiotensin II receptors in the cardiovascular system.
Step-by-step explanation:
Beta blockers and ACE inhibitors are cardiac therapeutics that inhibit the action of two G-protein-coupled receptors (GPCRs) in the cardiovascular system. Beta blockers specifically block the action of beta-adrenergic receptors, while ACE inhibitors block the action of angiotensin II receptors.
Beta blockers, such as metoprolol or propranolol, work by blocking beta-adrenergic receptors in the heart, which reduces heart rate and blood pressure. This helps to relax and widen blood vessels, making it easier for the heart to pump blood. ACE inhibitors, such as lisinopril or enalapril, inhibit the action of angiotensin II receptors, which reduces the production of a hormone called angiotensin II. This hormone constricts blood vessels and triggers the release of another hormone called aldosterone, which leads to water and sodium retention, increasing blood pressure.