Murray's sheep thyroid extract for myxedema

In November 1883 Felix Semon told the Clinical Society of London that myxedema, cretinism and the wasting that followed surgical removal of the thyroid all had one cause: loss of the thyroid gland. A committee of the Society agreed in its 1888 report, drawing on Victor Horsley's thyroid removals in monkeys. Replacing the gland was the next idea.

Horsley suggested grafting sheep thyroid. In June 1890 Bettencourt and Serrano in Lisbon put half a sheep's thyroid under the skin below each breast of a patient. The graft seemed to work before it could have gained a blood supply, and they concluded that juice from the gland was being absorbed. On 15 November 1890 Antonio-Maria Bettencourt-Rodrigues reported benefit from thyroid injections to the Lisbon Society of Medical Sciences. That result appeared only as a note in the society's proceedings.

George Murray, three years qualified, knew of the Lisbon graft but apparently not of the injections. On 12 February 1891, advised by Horsley, his former teacher, he proposed to the Northumberland and Durham Medical Society that myxedema be treated with an extract of sheep thyroid given under the skin. The medical college at Newcastle refused to help.

He obtained fresh sheep thyroids from a slaughterhouse. From 13 April 1891 he injected a 46-year-old woman with 1.5 ml of extract twice a week, and within three months she was dramatically better. His note appeared in the BMJ on 10 October 1891. A follow-up in 1892 added three more patients. Two of them improved and then died suddenly of cardiac failure, which Murray took as a warning that patients with weak hearts could die from exertion they were no longer used to. Two patients shown at that year's British Medical Association meeting failed to respond; years later Murray learned that the butcher had supplied thymus, not thyroid.

Other doctors soon reported that thyroid worked by mouth, and Murray moved his first patient to oral extract. She took it for 28 years and died at 74, having used about 5 litres of extract drawn from some 870 sheep.