VASODILATATION IN THE LIMBS IN RESPONSE TO WARMING THE BODY; WITH EVIDENCE FOR SYMPATHETIC VASODILATOR NERVES IN MAN

Journal/Book: Heart Volume 16 1931. 1931;

Abstract: From the Department of Clinical Research University College Hospital Medical School. *Work undertaken on behalf of the Medicinal Research Council. IN studying disorders of the peripheral circulation it is frequently desirable to produce vasodilatation in the limbs in order to see to what extent and in what circumstances the vessels will dilate. Brown produced fever by the intravenous injection of typhoid vaccine and investigated the consequent peripheral vasodilatation. In this department anæsthetisation of peripheral nerves has been used. Morton and Scott employed the rise of skin temperature of the feet occurring during lumbar anæthesia to differentiate spasmodic and organic obstruction of the arteries. The simplest method so far used is to raise the temperature of the room in which the subject is. This produces vasodilatation in the limbs in part by the direct effect of temperature an their vessels and in part by an effect through the central nervous system. To climinate the former and to produce peripheral vasodilatation entirely through the sympathetic nerves we designed the following method. Method. The subject is warmed in s chamber being seated on a chair with the head and neck and the extremities to be examined unenclosed. The chamber shown in Fig. 1 consists of a light wooden frame covared with an inner layer of canvas and an outer layer of thick felt and is made in two parts the function of these being indicated by the dotted line in Fig. 1 (without Fig. 1). It is heated by 10 carbon filament lamps carried by a bracket standing on the floor surrounding the subject's chair and inside the frame. The subject sits with the forearms projecting through the openings in the front wall of the chamber the hands resting an the cork platform. Temperatures of the skin of the hands and d the air surrounding them are recorded thermoelectrically. At the desired time the remainder of the chamber is applied over the subject's head and fastened to the front wall the purse strings around neck and arms tightened and the lamps lighted. ... ___MH

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