TY - JOUR T1 - CATECHOL, A FACILITATORY DRUG THAT DEMONSTRATES ONLY A PREJUNCTIONAL SITE OF ACTION JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 129 LP - 135 VL - 184 IS - 1 AU - J. P. GALLAGHER AU - L. C, BLABER Y1 - 1973/01/01 UR - http://jpet.aspetjournals.org/content/184/1/129.abstract N2 - Catechol increased the frequency of miniature end-plate potentials without altering their amplitude or time course. This drug also increased the amplitude of end-plate potentials in the presence and absence of d-tubocurarine without changing their rise time or half-fall. In analyses of quantal content, readily available stores, fractional release, quantum size and mobilization, catechol's anti-d-tuboeurarine action was attributed to an increase in the fractional release accompanied by an increase in the mobilization rate. In the absence of d-tubocurarine, catechol's facilitatory action, although less, is primarily due to an increase in the fractional release. There was no change in the effective membrane resistance or equilibrium potential after catechol. Comparisons were made to alpha adrenoreceptor activating catecholamines and their role in transmitter release. © 1973 by The Williams & Wilkins Company ER -