Abstract
Tyramine, amphetamine, cocaine, chlorpromazine, imipramine, reserpine, guanethidine and Dibenzyline (phenoxybenzamine) markedly reduced the concentration of administered H3- norepinephrine in the heart, spleen and (except for guanethidine) adrenal gland. These drugs lowered the H3-catecholamine concentration to a moderate degree in the liver. Imipramine was the only drug that lowered the H3-catecholamine in the skeletal muscle. The level of H3- normetanephrine was decreased by all these drugs in heart and spleen and in some cases in the adrenal gland and liver.
Tyramine, amphetamine, cocaine, chlorpromazine, imipramine, reserpine, guanethidine and Dibenzyline also elevated the plasma levels of administered H3-norepinephrine for the first 5 minutes. The plasma levels of H3-normetanephrine were also raised to varying degrees. These drugs appear to be acting by preventing the entry and/or the binding of H3-norepinephrine. The following drugs had no significant effect on the tissue and plasma concentration of H3- norepinephrine and H3-normetanephrine: Regitine (phentolamine), dichlorisoproterenol, TM 10 B, hexamethonium and ouabain.
The catechol-O-methyl transferase inhibitor, pyrogallol, elevated the concentration of H3- norepinephrine in heart, spleen, liver and muscle but not the adrenal gland and plasma, and lowered the concentration of H3-normetanephrine in these tissues except the heart and spleen.
Catron, a monoamine oxidase inhibitor, had no effect on the tissue levels of H3-norepinephrine in these tissues (except skeletal muscle) and elevated the concentration of H3- normetanephrine in all tissues.
Footnotes
- Received April 24, 1961.
- © 1961, by The Williams & Wilkins Company
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