THE ACTION OF JANUS GREEN UPON BLOOD-VESSELS

¹ Departments of Physiology, University of Edinburgh, and Queen's University, Kingston, and the Department of Medical Research, University of Toronto

1. Janus green exerts a powerful constrictor effect upon the pulmonary arteries of the guinea-pig, rabbit, and cat, so great and sustained indeed that the obstruction to the blood-flow may cause death through cardiac failure. The coronary arteries may also be affected, causing ventricular fibrillation. The systemic blood-vessels of the frog, guineapig, rabbit, and cat are also moderately constricted.

2. The constrictor action of Janus green is tachyphylactic. It is more readily demonstrated and can be provoked with smaller amounts in the perfused surviving blood-vessels than in the living animal, but in the former the perfusion with foreign sera and a high oxygen content of the tissues tend to diminish the reaction.

3. Strips of the aorta of the rabbit and cat, of the pulmonary artery of the rabbit, and of the carotid artery of the ox all fail to respond to solutions of Janus green in a Magnus bath. It has not been possible to reconcile this observation with the results described above.

4. The smooth muscle of the uterus, bronchiole, and ileum fails to respond to Janus green, but duodenal movements are depressed.

This research was commenced in Edinburgh in 1928-29, in Professor Sharpey-Schafer's laboratory. The experiments were continued at Queen's University upon my return to Canada, and in the Medical Research Laboratory of Professor Banting in Toronto.

I am indebted to Professor HAY, Kingston, for the photographs.

The expenses of the experiments performed in Edinburgh were met in part by a grant from the Earl of Moray Fund for the promotion of research in the University of Edinburgh.