ADRENALINE DESTRUCTION IN THE LIVER AND METHYLENE BLUE

¹ From the Laboratories of Biochemistry and Pharmacology, Oxford

1. The destruction of adrenaline in vitro by a liver suspension is inhibited by methylene blue but not by o-cresolindophenol. The former dye inhibits amine oxidase, whereas the latter does not.

2. Adrenaline injected into the portal circulation has less pressor action than when injected into the jugular vein. To obtain equal effects by the two routes the portal dose must be 4-5 times as great as the jugular dose. No such difference exists for pituitary (posterior lobe) extract.

3. The pressor effect of adrenaline injected into the portal system is greatly augmented if given simultaneously with methylene blue but not if given simultaneously with o-cresolindophenol.

4. The pressor effect of adrenaline injected into the jugular vein is augmented after the injection of methylene blue, but much less than that of adrenaline injected into the portal system.

5. The evidence indicates that in the liver in vivo the main instrument of adrenaline destruction is amine oxidase.