Abstract
The metabolism, distribution, uptake, release, and activity of m-aminophenylpropanolamine (MAPP), a nonphenolic amine, was studied in the mouse. Only a single radioactive peak was detected in urine after administration of tritiated MAPP. In distribution studies we found that tritiated MAPP and metaraminol (MA) were concentrated and retained in cardiac tissue compared to liver, spleen, kidney, and lung. Desipramine, cocaine, bretylium, and norepinephrine blocked the uptake of MAPP and MA into the mouse heart, whereas reserpine, guanethidine, and norepinephrine released both compounds from the heart. However, tyramine released MA but not MAPP. The effects of phenylpropanolamine analogs on uptake and release of tritiated norepinephrine were determined. All compounds studied. MA, MAPP. p-aminophenylpropanolamine (PAPP), and phenylpropanolamine (PPA) blocked the uptake of tritiated norepinephrine into the heart. Further, MA, MAPP, and PPA released tritiated norepinephrine from cardiac tissue, whereas PAPP had no effect. These results suggest that MAPP, like MA, may be specifically transported and stored in adrenergic neurons.
Footnotes
- Received November 26, 1973.
- Copyright © 1974 by The American Society for Pharmacology and Experimental Therapeutics
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