INFLUENCE OF DEPRESSANTS ON RATE OF ASPHYXIATION OF FROG'S VENTRICLE

¹ The Department of Pharmacology, University of Edinburgh

1. The rate of asphyxial exhaustion in the empty and contracting ventricle is about two-thirds that of the full and contracting ventricle and twice that of the ventricle when arrested and either filled or empty. The passage of a wave of excitation over the ventricle therefore causes a considerable increase in metabolism although no work is performed (correction of conclusions of Clark and White [1928 and 1930]).

2. The resting metabolism of the ventricle has a Q/10 of about 2 between 5° C. and 25° C. (confirming Weizsäcker, [1912]).

3. The metabolism added by contraction (total metabolism-resting metabolism) is lower at 5° C. than at 10° C., but the effect on this value of increasing the temperature above 10° C. is uncertain.

4. Acetylcholine reduces the metabolism of the arrested ventricle to about one-half of its normal value.

The expenses of this research were defrayed by a grant from the Moray Research Fund, for which the author desires to express his thanks.