THE EFFECTS OF CERTAIN ANIMAL EXTRACTS UPON THE BLOOD‐VESSELS

Suprarenal extract in the form of hemisine causes marked constriction of the vessels of all the organs, with the exception of those of the heart and lungs. In the heart it does occasionally produce slight constriction, but more often has no effect. In the lungs slight constriction is more frequently observed than is the case with the heart. Pituitary Extract.—The evidence from the experiments indicates that there are at least two substances—one causing contraction and the other relaxation—in this extract. Each is capable of producing its characteristic effect (this varying with the composition of the Ringer solution) on all the arteries except the renal, where contraction is hardly ever obtained, the result being nearly always relaxation. The subject of this research was suggested by Professor Schäfer, to whom I have been indebted for advice. The work was performed during my tenure of the Vans Dunlop Research Scholarship. The expenses have been defrayed out of the Earl of Moray Fund of the University of Edinburgh.