[Effects of oxilofrine on the activity of the sympathetic nervous system (author's transl)]

The effects of 1-(4-hydroxyphenyl)-2-methylamin-propanol- (1) (oxilofrine, 4-HMP) on the catecholamine metabolism were investigated in vitro in isolated rat hearts and spleen sections. Investigations were conducted in vivo to determine the influence exerted by the sympathomimetic agent on the noradrenaline biosynthesis in the heart and on the oxygen-dependent enzymes tyrosine hy droxylase and dopamine-beta-hydroxylase. Oxilofrine is an excellent inhibitor of the noradrenaline storage in the heart (DI = 1.5 X 10(-6) mol/l). At the same time, the sympathomimetic agent releases noradrenaline from the storage compartments. In this process, preferably newly synthetised noradrenaline is released both from the heart and from the spleen. This double mechanism of action is associated with an acceleration of the noradrenaline biosynthesis and an increase in enzymal activity of tyrosine hydroxylase and dopamine-beta-hydroxylase. The transmitter concentrations in the region of the postsynaptic receptors are enhanced by oxilofrine.