SUPRA-RENAL EXTRACT. In medicine, the sterilized glycerin extract of the supra-renal gland of the sheep, the dose being 5 to 15 minims. The active principle adrenaline or epine phrine occurs only in the medulla of the gland. It forms minute white crystals, soluble in weak solutions of hydrochloric acid and is most frequently used in I% solutions of the chloride.
Adrenaline has no action on the unbroken skin, but applied to mucous membranes it causes blanching by stimulating the mus cular fibres of the arterioles. It acts rapidly in a similar manner when hypodermically injected. The vessels of the uterus are strongly acted upon by it, but the effect on the cerebral vessels is slight, and the pulmonary vessels are unaffected. The heart is slowed and the systole increased. Adrenaline stimulates the sali vary glands, produces a temporary glycosuria, and in poisonous doses causes haemorrhages into the viscera and oedema of the lungs.
In Addison's disease the use of supra-renal extract has been beneficial in some cases, but its chief use is in the control of hae morrhage. For this purpose it is given in conjunction with local anaesthetics such as cocaine in order to produce bloodless opera tions on the eye, nose and elsewhere. It is also useful in haemor rhage from small vessels, where it can be applied at the bleeding spot, as in epistaxis. In surgical shock and in chloroform syncope an injection of adrenaline often saves life through the rise of blood pressure produced. An attack of bronchial asthma may be cut short by a hypodermic injection of adrenaline solution. It
should never be used in the treatment of haemoptysis. Similar commercial products on the market are hemisine, renaglandine, suprarenine, adnephrine, paranephrine and renostyptine. Supra renal snuff containing the dry extract with menthol and boric acid is of use in hay fever. Rhinodyne is of this type. Suppositories containing supra-renal extract are employed successfully to check bleeding piles.
The chemistry of adrenaline has been mainly elucidated by the investigations of Pauly, Jowett and Bertrand; Jowett proposing a constitution (see annexed formula) now accepted as cor rect. Many substances having related constitutions have been synthesized, and resemble ad renaline in increasing the blood pressure. For example, the corresponding ketone, adrenalone (ob tained in 1904 by Stolz) is active, and the methyl group can be replaced by hydrogen or another radical without destroying the ac tivity. It seems that the para-hydroxyl group is essential. For instance, para-hydroxyphenylethylamine, which is one of the active bases of ergot, closely resembles adrena line (G. Barger, Journ. Chem. Soc., 1909 95, pp. 1123, 172o; K. W. Rosenmund, Ber., 1909, P. ; as does also its dimethyl derivative hordenine, an alkaloid found in barley (G. Barger, ibid., p. 2193). Adrenaline is optically active, the naturally occur ring isomer being the laevo form; like nicotine, the laevo base has a much greater physiological activity than the dextro. (See ADRENALIN ; ANIMAL EXTRACTS.)