A method of standardising pituitary (infundibular) extracts / by H.H. Dale and P.P. Laidlaw.

  • Dale, Henry Hallett, 1875-1968.
Date:
1912
Catalogue details

Licence: In copyright

Credit: A method of standardising pituitary (infundibular) extracts / 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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    use had been made up with only half the correct proportion of calcium chloride. On making up a new batch correctly we again obtained the almost uniform response to successive equal doses which is the chief advantage of the method. It is clear, then, that an adequate calcium content of the bathing fluid is an important factor in restoring the sensitiveness of the uterus after an effective dose of the extract. The volume we have used in the bath is 250 cc., with winch the lamp-glass chamber which we use is about three-quarters filled. The water in the outside jacket is adjusted to stand at the same level, and serves as a guide to the refilling of the bath with the same volume of fluid at each change. Young virgin guinea-pigs, of not more than 350 grams weight, usually give the best results. With older animals the uterus is apt to show too much automatic rhythm and to be too sensitive, though it may occasionally give an easily interpreted record. The animal is killed by a blow on the head and bled out as com- pletely as possible. Some experiments undertaken for another purpose suggest that more uniformly good results might be ob- tained by perfusing the uterus thoroughly with the Ringer’s solution, through the aorta, before excision; but the procedure is probably not worth the trouble involved for routine use. All the results dealt with in this paper have been obtained with the organ simply excised and suspended after bleeding the animal. A horn of the uterus is removed by cutting through the broad liga- ment close to it along its entire length. The incision is carried forward so as to excise the ovary as well, which is left attached to the uterus by the fold of broad ligament in which the Fallopian tube runs. The pin at the lower end of the oxygen-tube is pushed through the lower end of the horn, and the hook suspended from the recording lever is passed through the ovary. The oxygen- tube is then lowered into the bath of Ringer’s solution, to such a depth that the lever is pulled well beyond the horizontal position. The manipulation and exposure, followed by immersion in the warm bath, will be found almost invariably to produce a high degree of tonus. When the uterus is left to itself the tone slowly gives way, with small rhythmic interruptions, until a condition of almost complete relaxation is attained. The ideal uterus for our