Influence of clonidine on experimental hypertension induced by cholinergic stimulation

Hypertension may be induced by pharmacologic activation of central cholinergic receptors either indirectly, through the injection i.v. of physostigmine, or directly, through the injection of i.v. of arecholine in anesthetized rats. Activation of peripheral preganglionic cholinergic receptors with dimethylphenylpiperazinium iodide (DMPP) also produced a hypertensive response. Pretreatment with various doses of clonidine caused inhibition of the pressor response to central cholinergic stimulation but was without effect on the response to ganglionic cholinergic stimulation.