TY - JOUR T1 - INHIBITORY EFFECT OF MANGANESE ON NOREPINEPHRINE RELEASE FROM THE SPLENIC NERVES OF CATS JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 72 LP - 76 VL - 174 IS - 1 AU - S. M. KIRPEKAR AU - W. DIXON AU - J. C. PRAT Y1 - 1970/07/01 UR - http://jpet.aspetjournals.org/content/174/1/72.abstract N2 - Norepinephrine (NE) was released from perfused spleens either by nerve stimulation or injection of potassium in phenoxybenzamine-treated and normal cats. Krebs-bicarbonate solution was perfused at a rate of about 7 ml/min at 35°C. Perfusion of the phenoxybenzamine-treated spleens with 2.5 mM Mn++ Krebs' solution reduced the NE outputs to low levels. Perfusion of the normal spleens, pre-exposed to H3-NE infusion, with 0.8, 2.5 or 5 mM Mn++ Krebs' solution also significantly reduced the net increases in radioactivity, H3-NE and NE by nerve stimulation. Increasing the Ca++ concentration to 10 mM did not significantly alter the inhibitory effect of Mn++. Mn++ also blocked the spontaneous release of radioactivity from spleen. It is concluded that Mn++ acts as a potent inhibitor of NE release and blocks both the nerve-induced and spontaneous release of NE. © 1970, by The Williams & Wilkins Company ER -