Adrenaline reversal
As adrenaline reversal are in pharmacology or in the physiology of two different effects referred.
One is the paradoxical effect of lowering blood pressure after adrenaline administration observed during therapy with alpha blockers such as prazosin , doxazosin , phentolamine or ergot alkaloids . This effect is attributed to the blockage of blood vessel-contracting and thus blood pressure-increasing α 1 -adrenoceptors by alpha blockers, so that adrenaline selectively mediates its effects via blood vessel-expanding and thus blood pressure-lowering β-adrenoceptors .
The other effect, which is sometimes referred to as reversal of adrenaline, refers to the isolated effect of adrenaline on certain resistance vessels in the bloodstream, the arterioles . Some resistance vessels have a high density of β 2 -adrenoceptors, for example those of the skeletal muscles. In these vessels, low concentrations of adrenaline have a vasodilator effect via the β 2 -adrenoceptors. At high concentrations, however, the effect on the α-adrenoceptors that are also present predominates, so that a constriction then occurs.
Individual evidence
- ↑ Ernst Mutschler, Gerd Geisslinger, Heyo K. Kroemer, Peter Ruth, Monika Schäfer-Korting: drug effects. Textbook of pharmacology and toxicology. 9th edition. Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart 2008, ISBN 3-80-471952-X
- ↑ Speckmann, Hescheler, Köhling: Physiology. 5th edition 2008, page 428. ISBN 978-3-437-41318-6