%0 Journal Article %A K. J. FRANKLIN %T THE PHARMACOLOGY OF THE ISOLATED VEIN RING %D 1925 %J Journal of Pharmacology and Experimental Therapeutics %P 215-225 %V 26 %N 3 %X The parallelism between the results of experiments with adrenaline on the isolated vein ring and sympathetic stimulation in the experimental animal has been taken to justify the study of the action of other drugs on similar preparations of various veins. In the doses stated and with the veins used the results have been as follows. Contraction has been caused by adrenaline, alcohol, barium, calcium, potassium, large amounts of chloral hydrate, digitalin, ergamine, ergotoxine, ether in some cases, nicotine, pituitrin, and strophanthin. Relaxation has been caused by adrenaline after ergotoxine, small amounts of chloral hydrate, ether in some cases, nitrite, carbon dioxide, and urethane. No effect has been caused by atropine, acetyl-choline, pilocarpine, apocodeine, caffeine, theobromine, diuretin, cocaine, magnesium, quinidine, and strychnine. Rhythmical movements have been observed in veins before the application of any drug, and also under the influence of adrenaline, ergamine, and ergotoxine. Twitches have been observed in the superior vena cava, and their duration corresponds with that of rhythmic movements recorded in some unpublished experiments performed in 1915 by Professor J. A. Gunn on the rabbit. In these a single contraction occupied 3/10 to 4/10 second. In the sheep's vena cava experiment in the present series, 1 mm. On the tracing represented about seven seconds, and the twitches observed, seven in all, recorded single lines only on the tracing. These lines were not demonstrably thicker at the top than at the bottom. Three observers who saw them were struck with the rapidity of these twitches, which resembled that of skeletal muscle contractions. %U https://jpet.aspetjournals.org/content/jpet/26/3/215.full.pdf