EFFECTS OF CERTAIN DKUGS AND POISONS 741 



by piqure and the emotions, appears to be of central origin. It cannot 

 occur when the liver glycogen is exhausted. MacLeod has shown that, 

 although it can still be produced with the liver denervated, it is prevent- 

 able by double splanchnotomy,. or excision of both adrenals. The effect 

 is apparently due to increased hydrogen ion concentration of the blood 

 (compare the acid glycosuria of Pavy) acting through the nervous centers, 

 but involving often the cooperation of the adrenals. 



Kellaway(tt) (b) produced asphyxia by causing animals to breathe gas. 

 mixtures low in oxygen or high in carbon dioxid. Accelerated secretion of 

 epinephrin and hyperglycemia were observed, both being due mainly to 

 lack of oxygen, rather than to carbon dioxid excess. The hyperglycemia 

 was only in part caused by acceleration of the epinephrin output. In 

 anoxemia the ordinary mechanism of action is central, the splanchnics pro- 

 viding the path of the impulses. 



F. M. Allen enumerates a list of poisons to which the production of 

 asphyxial glycosuria has been attributed. Many of them will be discussed. 



Blood Alkalinity. Galleotti found in himself and several others as 

 a result of several days' residence upon Monte Rosa (4,560 meters) a re- 

 duction of 40 per cent in the blood alkalinity. 



Lactic Acid. Araki's(a) finding of increased lactic acid excretion in 

 conditions of oxygen-lack has been amply confirmed and so much stress 

 was at one time laid upon this feature that, as Lusk points out. it was 

 wrongly taken as pathognomonic of an asphyxial condition. 



Terray found that when the oxygen percentage in the inspired air 

 was reduced to 10.5 an increased respiratory activity commenced. With 

 half of this concentration there was every indication of oxygen-lack, and 

 the elimination of lactic acid became pronounced. The lactic acid elimi- 

 nated as a result of breathing 3 per cent oxygen varied in eight observa- 

 tions from 1.206 to 3.686 grams in twenty-four hours. 



Carbon Dioxid. Carbon dioxid acts as a weak acid, serving as the 

 respiratory regulating hormone. The central nervous system, especially 

 the medulla, is so sensitive to its stimulating effect that it may become 

 an important factor in the asphyxial phenomena just described. In high 

 concentrations, however, the gas evokes the symptoms of oxygen-lack in the 

 same way as when an indifferent gas such as hydrogen or nitrogen is in- 

 haled ; Loevenhart therefore refers its effects to interference with oxygena- 

 tion. Westenryk showed that carbon dioxid inhalation reduces the tem- 

 perature, Magyary-Ivossa finding this effect more marked in fever than 

 in health, and associsttcd with reduced oxidations. To produce glycosuria 

 10 to 15 per cent of carbon, dioxid (enough to narcotize) is required 

 (Edie, Moore and Roaf). 



Acapn-ia. Excess of carbon dioxid is rapidly blown off by the respira- 

 tory mechanism and over-compensation often occurs, resulting in a lowered 

 carbon dioxid content of the blood (Y. Henderson). Since this carbon 



