The hypothermic and anti-pyretic effect of preparations of A.C.T.H / W.W. Douglas, W.D.M. Paton.

  • Douglas, W. W.
Date:
1952?]
Catalogue details

Licence: In copyright

Credit: The hypothermic and anti-pyretic effect of preparations of A.C.T.H / W.W. Douglas, W.D.M. Paton. Source: Wellcome Collection.

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    For experiments with posterior pituitary hormone, extracts were made as described by Burn (1937) from samples of the Pituitary (Posterior Lobe) International Standard. To induce artificial pyrexia, a prepe ration of dried bacterial bodies from a strain of Proteus vulgaris was used, for which we are grateful to Dr. A. A. Miles. This material has been shown previously (F. C. Macintosh and W. D. M. Paton, unpublished) to raise the body-temperature 1° or 2°C in these rabbits, when injected in a dose of 1 p.g. per kg. of body-weight ; this pyrexial response typically begins in about 20—30 min., lasts for over 5 hours, and displays a transient partial defervescence 2—3 hours after the injection. RESULTS Hypothermic Effect of A.C.T.H. Preparations Each of the various batches of a.c.t.ii. lowered the rectal temperature when injected intravenously. The fall in temperature began within 15 minutes of injection and progressed steadily to reach its lowest point in about l1/2 hours. Recovery then took place and followed a somewhat similar time course, normal temperature being restored about 3 hours after the injection. Fig. 1 shows a typical range of responses obtained by the injection of a single sample (batch 4) in a dose of 1 unit per kg. of body-weight into each of eight rabbits. The response varies with the sample of a.c.t.h., with the dose given, and with the animal used, and considerably larger falls in temperature were sometimes observed. Thus, out of twenty-five tests with various batches at this dose level (1 unit per kg. of body-weight), the temperature fell more than 1°C on twelve occasions ; with a larger dose, 3 units per kg. of body-weight, the temperature fell more than 2-5°C in four out of twenty-one tests. The values obtained in our experiments are shown in the accompanying table. Many of the tests were made on rabbits which had already been injected with a.c.t.h. on one or more occasions ; since it was possible that previous exposures to a.c.t.h. might affect the response, the number of the exposure is given in parentheses after each result. Two main points emerge from consideration of A.C.T.H. 1 unit per kg.oF BODY-WEIGHT 1st.TEST 2 rid.TEST 3rd.TEST A.C.T.H. 3units per kg.of BODY-V/ESGHT 1 st.TEST 2 nd.TEST 7 5 H NUMBER OF ANIMALS W EACH GROUP Fig. 2—-Hypothermic responses of rabbits to A.C.T.H. 1 unit or 3 units per kg. of body-weight, with repeated tests on the same animals.