Organization of the sympathetic innervation of the forelimb resistance vessels in the cat.

Unlabelled: Detailed information on the outflow pathway of sympathetic vasoconstrictor fibers to the upper extremity is lacking. We studied the organization of the sympathetic innervation of the forelimb resistance vessels and of the sinoatrial (SA) node in the decerebrated, artificially respirated cat. The distal portion of sectioned individual rami T1-8 and the sympathetic chain immediately caudal to T8 on the right side were electrically stimulated while the right forelimb perfusion pressure (forelimb perfused at constant flow) and heart rate were recorded.

Synaptic inhibitory effects of edrophonium on sympathetic ganglionic transmission.

Purpose: To evaluate the effect of edrophonium on synaptic transmission in the superior cervical ganglion.

Methods: In anaesthetized rats the effect of edrophonium on synaptic transmission was studied in vitro by testing whether it blocks the compound action potential recorded from postganglionic fibres evoked by stimulation of preganglionic axons. The superior cervical ganglion was excised and the cervical sympathetic trunk and internal carotid nerve were used for stimulating and recording, respectively.

Bradycardia produced by pyridostigmine and physostigmine.

Purpose: The bradycardia produced by pyridostigmine and physostigmine in an animal model of acute cardiac denervation was examined according to its relation to cholinesterase inhibition and sensitivity to block by cholinergic receptor antagonists.

Methods: Cats were anaesthetised, vagotomised and propranolol-treated. Heart rate was continuously recorded.

Heart rate changes in cardiac transplant patients and in the denervated cat heart after edrophonium.

Purpose: The effect of edrophonium on heart rate in cardiac transplant patients and in an animal model of acute cardiac denervation were studied, to evaluate the functional state of the peripheral parasympathetic pathway following cardiac denervation.

Methods: Edrophonium was studied in patients with normally innervated hearts (controls) and in cardiac transplants. Edrophonium was also studied in vagotomized, beta-blocked cats.

Different properties of the bradycardia produced by neostigmine and edrophonium in the cat.

Purpose: The bradycardia produced by neostigmine and edrophonium was examined according to its relation to cholinesterase inhibition and to its sensitivity to block by muscarinic receptor antagonists. For comparison, the ability of muscarinic antagonists to block the bradycardia produced by electrical stimulation of the vagus nerve was determined.

Methods: Cats were anaesthetized, vagotomized and propranolol-treated.