RT Journal Article SR Electronic T1 The Uptake of Isoprenaline and Noradrenaline by the Perfused Rat Heart JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 37 OP 42 VO 2 IS 1 A1 B. A. CALLINGHAM A1 A. S. V. BURGEN YR 1966 UL http://molpharm.aspetjournals.org/content/2/1/37.abstract AB Isoprenaline is accumulated by the isolated heart when perfused through the coronary circulation. It is poorly bound by intracellular particles and readily removed by postperfusion. Uptake of isoprenaline is inhibited by normetanephrine but not by cocaine or metaraminol and corresponds to the Uptake2 of Iversen. The presence of isoprenaline does not convert the noradrenaline uptake process from Uptake1 to Uptake2, and it is therefore possible for these processes to coexist. The results can be explained if there is a mosaic of Uptake1 and Uptake2 sites on the plasma membrane of the sympathetic neuron. ACKNOWLEDGMENTS We wish to thank Miss S. M. Warren for skilled assistance, the Medical Research Council for a grant in aid, and Merck, Sharp and Dohme Ltd. for a gift of metaraminol.