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INNERVATION BOTH OF PERI‐ORBITAL STRUCTURES AND OF THE HEART BY THE CERVICAL SYMPATHETIC NERVES IN MOUSE, RAT, GUINEA‐PIG, RABBIT AND CAT
Author(s) -
LARGE B.J.
Publication year - 1975
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1975.tb07575.x
Subject(s) - phentolamine , hexamethonium , guanethidine , atropine , stimulation , superior cervical ganglion , nictitating membrane , sympathetic nervous system , cervical ganglia , autonomic nervous system , medicine , propranolol , guinea pig , endocrinology , cats , anatomy , heart rate , blood pressure , statistics , classical conditioning , mathematics , conditioning
1 In anaesthetized rats electrical stimulation of the intact cervical sympathetic nerve produced frequency‐dependent lower eyelid contractions and tachycardia. 2 The tachycardia was caused by excitation of efferent fibres since it was equally evident in the pithed rat preparation, and the right nerve was more effective than the left. By contrast, no differences were seen between the responses to right and left vagal stimulation in either rats or rabbits. 3 Guanethidine inhibited both cardiac and eyelid responses, propranolol only the former and phentolamine only the latter, thereby revealing the adrenergic nature of the nerves. Hexamethonium caused partial inhibition and the block was intensified by atropine. 4 The inferior eyelid of mice, guinea‐pigs and rabbits as well as the nictitating membrane of rabbits and cats were contracted by cervical sympathetic nerve stimulation. In these species too, tachycardia occurred; this was more pronounced with the right than the left sympathetic nerve. The order of cardiac responsiveness was mouse > rat > guinea‐pig > rabbit > cat. 5 In guinea‐pigs histamine‐induced bronchoconstriction was reduced by cervical sympathetic nerve stimulation. 6 That discrete cardiac pathways exist in the cervical sympathetic nerves is suggested by the reproducibility of the effects within any one species. The accessibility of the nerves greatly simplifies the examination of drugs in vivo on two different structures innervated by the sympathetic nervous system.