Dopahyperglykämie

Abstract

Rabbits which had been fasted 24 hrs., were injected subcutaneously with 5 mg. hydroxytyramine/kg. body wt. Blood sugar was detd. by the method of Hagedorn-Jensen. The blood sugar increased 80% within 45 min. after inj. The inj. of 0.05 mg. adrenaline/kg. body wt. produced an equal effect upon the blood sugar, but the maximum value was not reached until 90 min. In rabbits, the pressor effect of adrenaline was 500-1000 times greater than that of hydroxytyramine. Intravenous inj. of hydroxy-tyramine produced a slight transient hyperglycemia. In rabbits, subcut. inj. of 80 mg. dopa (dihydroxyphenylalanine) produced the same maximum rise in blood sugar as 10 mg. of hydroxytyramine. The maximum was not reached until 90 min., for time was needed for the amino acid de-carboxylase to change the inactive amino acid into the active hydroxytyramine. Two guinea pigs were injected intramusc. with 5 mg. 1-dopa. 2 with 2.5 mg 1-dopa, and 2 with 5 mg. d.l-dopa for 100 g./body wt. That the de-carboxylase acted only on the 1-form of the acid was shown by the fact that the animals which received 5 mg. doses d.l-acid and 2.5 mg. doses 1-acid excreted the same amt. hydroxytyramine, while the animals which received the 5 mg. doses of 1-acid excreted much more of the amine. Only the 1-form of the acid had a hyperglycemic effect in rabbits.