[Beta]-iminazolylethylamine : a depressor constituent of intestinal mucosa / by G. Barger and H.H. Dale.

  • Barger, George, 1878-1939.
Date:
[1911]
Catalogue details

Licence: In copyright

Credit: [Beta]-iminazolylethylamine : a depressor constituent of intestinal mucosa / by G. Barger and H.H. Dale. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    5/10 (page 501)
    a syrupy residue remained. This was treated with saturated aqueous solution of picric acid, and yielded 19 milligrams of a picrate which soon crystallised, and then melted at 228° C. On recrystallisation it formed yellow serrated needles and rhombic leaflets, melting at 232° C., which were quite similar to the crystals of /3-iminazolylethylamine dipicrate, and like the latter gave an intense colouration with p. diazo- benzene sulphonic acid (Pauly’s histidine reaction). The picrate thus corresponded chemically with the dipicrate of /3-iminazolylethylamine. For physiological comparison 10 mgms. of the recrystallised picrate were dissolved in dilute HC1 and the solution freed from picric acid by repeated shaking with ether. Ether was removed from the watery layer by boiling, and the solution was neutralised and made up to 4 c.c. Assuming that the substance was correctly identified each c.c. would then contain approximately 0'5 mgm. of the base as hydrochloride. This is called solution A. For comparison a 0'05°/0 solution of /3-I. hydrochloride, obtained from histidine, was used, and is called solution B. Fig. 1. For description see text. Upstroke = contraction. Fresh Ringer at j |. The following experiments were made : (1) An isolated horn of the uterus of a virgin guinea-pig was suspended in a bath containing 250 c.c. of oxygenated Ringer’s solu- tion at 38 C. Addition to the bath of (a) O'l c.c. of solution A (= 0'05 mgm. of base from intestines); (b) 01 c.c. of solution B (= 0'05 mgm. of /9-I.) produced very similar contractions of the uterus (Fig. 1). Solution A, presumably containing O'l °/0 of base,- was as