STUDIES ON VERATRUM ALKALOIDS. XXIX. THE ACTION OF SOME GERMINE ESTERS AND OF VERATRIDINE UPON BLOOD PRESSURE, HEART RATE AND FEMORAL BLOOD FLOW IN THE DOG

¹ Department of Pharmacology, University of Buffalo, School of Medicine, Buffalo, New York
² Department of Pharmacology, Harvard Medical School, Boston, Massachusetts
³ Department of Pharmacology, Women's Medical College, Philadelphia, Pennsylvania

Four esters of germine, differing in the number of ester linkages and the nature of the participating acids, and veratridine have been investigated for their effect upon blood pressure, heart rate, right atrial pressure and blood flow in the perfused hindlimb of the dog. There were no qualitative differences between germerine, neogermitrine, desacetylgermitetrine and veratridine. Germitetrine had a slower onset and a longer duration of action and its maximally obtainable effects were smaller. The variations in potency between the esters were only small; the germine esters as a group were 3 to 5 times more potent than veratridine.

All the hypotensive esters investigated caused a vasodilatation in the vascular bed of the femoral artery which was transmitted by nervous pathways. The dilatation was not influenced by atropine and can therefore not be mediated by cholinergic dilator nerves. Its magnitude was not closely related to the magnitude of the accompanying hypotension, and it is likely that the fall in blood pressure induced by these alkaloids is not entirely due to a decrease in peripheral resistance.