THE INFLUENCE OF TRIIODOTHYRONINE ON THE RELEASE OF ACETYLCHOLINE BY A PHRENIC NERVE DIAPHRAGM PREPARATION

Abstract
SUMMARY: A concentration of 0·01 μg. (—)-triiodothyronine in the Tyrode's fluid bathing a phrenic nerve diaphragm preparation has been shown to decrease the acetylcholine appearing in the bath fluid in response to tetanus of the diaphragm through the phrenic nerve at a fixed number of impulses per sec. for a fixed number of minutes, when (a) eserine (40 μg./ml.) was used to inhibit the cholinesterase and the acetylcholine was assayed on leech muscle; and (b) prostigmine (5 × 10-6) was used as the anticholinesterase and the acetylcholine was assayed by its depressor effect on the arterial pressure of rats.