Myocardial Cholinergic Receptor Sites and Enzyme Activity in the Dahl Model of Essential Hypertension

Abstract

The density of muscarinic receptor sites, choline acetyltransferase (ChAT), and aceytlcholinesterase (AChE) activity in the myocardium of the Dahl salt-sensitive (DS) and salt-resistant (DR) rat was investigated. Both normotensive and hypertensive (as a result of 8.0% NaCl added to the diet) DS rats displayed a lower concentration of muscarinic receptors and less ChAT and AChE activity in myocardial tissue than normotensive DR rats. Lower receptor site density and enzyme activity in the myocardial of the DS line may reflect decreased vagal tone. If true, this may produce deficits in the ability to appropriately adjust heart rate (HR) in response to elevations in blood pressure (BP). Therefore, the present results may be viewed as exacerbational factors in the pathogenesis of hypertension in the DS line.

Key Words:

• Muscarinic Receptor Sites
• Choline Acetyl-transferase
• Acetylcholinesterase
• Dahl Rate
• Myocardium