Effects of dihydroergotamine in athyroid and thyroxinized rats

Abstract

Athyroid and athyroid-thyroxinized rats showed an increase in oxygen consumption that was linear with the log of the dose of thyroxine. Epinephrine elevated the level of O2 consumption, but the response was still linear with respect to the log of the thyroxine dose. Dihydroergotamine had a slight depressant effect on the O2 consumption of all groups, but did not affect the linearity of response. Epinephrine plus dihydroergotamine caused a response similar to that seen when no drugs were administered. The effects of the various treatments on blood sugar levels were exactly parallel to those obtained with O2 consumption measurements. The data do not support the concept that the action of thyroxine on tissues of the organism is mediated via epinephrine.