REGULATION OF BLOOD PRESSURE LEVELS BY HEXAMETHONIUM BROMIDE AND MECHANICAL DEVICES

Abstract

Probably the first studies of the pharmacology of quaternary ammonium compounds were made by Crum-Brown and Fraser in 1868. Burn and Dale (1915) found that, unlike nicotine, tetra- ethyl-ammonium chloride blocked autonomic ganglia without noticeable initial stimulation. Barlow and Ing (1948a and b), Paton and Zaimis (1948a and b), and Balaban et al. (1949) studied the properties of some chemical relatives of tetra-ethyl-ammonium in which two quaternary nitrogen groups were separated by a chain of CH2 groups. It was found that decamethonium with ten CH2 groups was curare-form, and pentamethonium and hexamethonium with respectively five and six CH2 groups were predominantly ganglion blocking agents. For example, Paton and Zaimis (1949) showed that intravenous injection of pentamethonium iodide relaxed the cat's nictitating membrane which had been caused to contract by preganglionic stimulation. Pentamethonium iodide also prevented the pulse-slowing action of vagal stimulation. Kay and Smith (1950) showed that hexamethonium iodide lessened the secretory response to insulin-induced hypoglycemia but did not prevent the response of gastric secretion to histamine. All of these results are consistent with the view that penta-and hexamethonium salts act chiefly by blocking autonomic ganglia.