The physiological action of [beta]-iminazolylethylamine / by H.H. Dale and P.P. Laidlaw.

  • Dale, Henry Hallett, 1875-1968.
Date:
[1910]
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: The physiological action of [beta]-iminazolylethylamine / by H.H. Dale and P.P. Laidlaw. 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.

    25/30 (page 339)
    The stomach and intestines. The vomiting and purging produced in the unanaesthetised cat by intravenous injections of >3-1. have already been mentioned. In the anaesthetised or pithed animal the effects on the exposed viscera of smaller injections (0'25—0'5 mgm.) are less striking, but still quite obvious. Both tone and rhythm appear to be augmented. An isolated loop of intestine, whether perfused artificially or simply suspended in warm oxygenated Ringer’s solution, is more responsive to the stimulating action of the base than the undisturbed intestine with normal circulation. Fig. 19 (supra) shows the effect, on a short loop of cat’s jejunum, suspended in the saline bath, of adding 05 mgm. >3-1. to the bath, which had thus a concentration of 1 part of the base in 500,000. The effect is not abolished by atropine. The urinary bladder. In the intact animal the injection of >3-1. frequently causes evacua tion of the bladder. A record of the volume of the bladder contents in a pithed cat, by means of a catheter connected with a reservoir half filled with water, which again communicated with a bellows recorder, showed, as the result of a first injection of 0'25 mgm. /3-I., a small relaxation of the bladder wall. Subsequent injections produced in every case a contraction of the bladder, the contractions becoming progressively larger Avith each injection, till the sixth injection produced a contraction leading to the expulsion of more than 40 c.c. of the contents. That this contraction Avas not due to direct effect on the musculature of the bladder Avas shoAvn, hoAvever, by the fact that, after destruction of the sacral cord, a further injection caused practically no change of bladder volume. We found little evidence, indeed, that the base has any marked direct effect on bladder muscle. All the effects Avhich Ave observed can fairly be attributed to the stimulation of centres in the cord by the anaemia-caused by fall of arterial pressure. The plain muscle of other organs. The retractor penis of the dog or goat is throAvn into tonic con- traction by small doses of /3-I. Good responses Avere obtained, Avhen the muscle Avas treated as an isolated organ, Avith dilutions of I in 250,000.