RT Journal Article SR Electronic T1 RELEASE OF AUTONOMIC MEDIATORS IN CARDIAC TISSUE BY DIRECT SUBTHRESHOLD ELECTRICAL STIMULATION JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 185 OP 194 VO 141 IS 2 A1 Frank F. Vincenzi A1 Theodore C. West YR 1963 UL http://jpet.aspetjournals.org/content/141/2/185.abstract AB Electrical stimuli which are subthreshold for myocardial excitation have been shown to be effective in causing the release of autonomic mediators in several types of cardiac tissue derived from rabbit, guinea pig, dog, and cat. Strength-duration data have been presented illustrating the relative case with which subthreshold release of the autonomic mediators may be demonstrated in rabbit SA node, AV node, and left atrium. It is proposed that both subthreshold and threshold electrical stimulation act upon intramyocardial autonomic nervous elements to cause the release of acetylcholine and norepinephrine. The significance of the release of acetylchohine and/or norepinephrine in procedures involving electrical stimulation is discussed.