Cholinergic receptor site binding, choline acetyltransferase, and acetylcholinesterase activity in the forebrain and brainstem of the Dahl rat model of essential hypertension.

Muscarinic and nicotinic receptor site binding and the activity of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) in the forebrain and brainstem of Dahl salt-sensitive (DS) and salt-resistant (DR) rats was investigated. The DS line had a greater density of muscarinic sites in the cortex, hypothalamus, and medulla. Hypertensive DS rats had a greater density of sites than normotensive DS rats. ChAT activity was also higher in the cortex and hypothalamus of the DS line than the DR line. No significant differences were found in the activity of AChE or the concentration of nicotinic sites. These results suggest that the central muscarinic cholinergic system may participate in the pathogenesis of hypertension in the DS rat. The data indicate that central cholinergic activity is possibly greater in the DS than the DR rat and that this may help to explain the enhanced pressor response in the DS line after pharmacological activation of the central cholinergic system.