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.

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    rodents than in carnivora. For this reason the condition of anaesthesia, and the length of time during which the animal has already been under the anaesthetic when the injection is given, have a considerable influence on the result. It was pointed out by Brodie and Dixon1 that the response of the bronchial muscles is depressed by various anaesthetics, especially by urethane, which can even obscure the bronchio-constrictor effect of muscarine. We have seen that bronchial spasm is a typical feature of the action of /3-I. on the unanaesthetised rabbit or guinea-pig. We have also seen that, under these conditions, >3-1. is as fatal to the rabbit as Ackermann and Kutscher found the ergot-base. It seemed Fig. 9. Rabbit. Urethane. Effect of 1 mgr. /3-I. on blood-pressure. possible,'therefore, that the relatively harmless effect of /3-I. in their experiments might be counected with their use of urethane as an anaesthetic. We therefore made observations on the blood-pressure of rabbits anaesthetised with urethane for varying periods, and a com- parison of the results of the two following experiments is instructive. Each of two rabbits was anaesthetised by an injection of urethane solution, 1*5 grms. per kilo, being given in each case. In the first rabbit, as soon as complete anaesthesia was produced, the operation of inserting the necessary cannulae was rapidly completed. The record was then started and an injection of 1 mgm. /3-I. given intravenously. Fig. 9 shows the effect on the carotid blood-pressure. It will be seen