On the Combined Effect of Neostigmine and Pentamethylenetetrazol or β‐phenylisopropylamine on Magnesium Anaesthesia.

Abstract

It has long been well known that a sufficiently high concentration of magnesium ions in the tissues causes a condition resembling that of anaesthesia (JOLYET and CAHOURS, 1869). A great many investigations seem to show that this magnesium anaesthesia is due, in part at least, to an obstruction of neuromuscular transmission ( W m , 1906; BARDIER, 1907 ; MATTHEWsand BROOKS 1910, and others). Other observers, however, are of opinion that the activity of the central nervous system is also reduced (MELTZER and AUER, 1905 and later). A more complete survey is availablein works by GRAM, 1919; ESKELUND, 1931 and ENOBZK, 1948. Hitherto it has not been clearly demonstrated which of the two mechanisms takes predominales in the anaesthesia.In this paper we attempt to contribute to the knowledge of the mechanism of magnesium anaesthesia. We have examined the effect of various possible antagonists, such as neostigmine, pentamethylenetetrazol and j?-phenylisopropylamine. (1933) found that the respiration of experimental animals in magnesium anaesthesia was stimulated by different analeptics. A still stronger effect was obtained by injection of eserine (JOSEPH and MELTZER, 1909 ; STARKENSTEIN, 19 14 ; ESKE- LUND, 1931). Consequently eserine is reported t o increase the M. L. D. of magnesium. On the other hand magnesium also Actn plinrniacologira vol. 5 , fiw. 4. TOSCANO RICO