318 PROFESSOR E. A. SCHAFER AND DR H. J. SCHARLIEB ON THE 
The action of chloroform upon the vessels when perfused through the isolated organs 
is a direct action upon the muscular tissue, and not, as in the case of suprarenal extract, 
upon the terminal apparatus of the vasomotor nerves. This is shown by the fact that 
apocodeine, which in sutticient dose abolishes the effect of adrenalin,* does not abolish 
the effect of chloroform in producing vasoconstriction. 
The following experiment may be quoted in illustration of this statement :— 
Hind Limb of Rabbit.—Perfusion with 1 in 2000 chloroform reduced the rate of flow during each period of 
time from 44 ¢.c. to39¢.c, After recovery, perfusion with 0°0001 gramme hemisine (adrenalin) added 
to the normal Ringer brought it down to 10 c¢.c, After recovery, perfusion with Ringer solution, 
containing 0°0001 gramme hemisine and 0:0075 gramme apocodeine, caused only a slight reduction, 
soon disappearing. After recovery, admixture with the perfusing fluid of 10 e.c. of chloroform- 
Ringer (=1 in 500), containing 0°02 gramme apocodeine, caused an almost complete arrest of flow 
during several minutes. Fig. 4 is a graphic record of this experiment. 
In all cases the drugs were injected into the tube which supplied the normal Ringer, and the 
solution became mixed with a certain proportion of this, and warmed to the same temperature by 
passing through the glass spiral before reaching the organ which was perfused. 
As a further proof that chloroform acts upon the muscular tissue of the arterioles m 
Fic. 4.—Effect of injecting 10 c.c. of chloroform-Ringer (=1 in 500) containing 0°02 gramme apocodeine through the vessels of 
the hind limb of the rabbit. 
a, b, c, d@asin fig. 8. The tracing is taken on a more slowly moving surface than that in fig. 8. The initial pressure 
of the perfusion fluid was lower in this experiment than in the experiment shown in fig. 3, and the supply less free: this, 
as well as more complete constriction of the arterioles, accounts for the fact that the manometer tracing is much affected 
in the one case and scarcely at all in the other. 
producing contraction may be adduced the observation that its action can be got after 
the neuro-muscular end-apparatus has lost its irritability. Thus in the kidney of a 
rabbit, which had been killed three hours previously and in which the injection of 
0:0003 gramme hemisine (adrenalin) produced no effect whatever upon the rate of flow, 
injection of 20 c.c. of 1 in 200 chloroform-Ringer into the supply-tube reduced the rate 
from 56 ‘cc. to 28) ¢-¢: 
All recent observers are agreed that the fall of blood-pressure which is caused by 
chloroform is essentially due to its effect upon the heart muscle, the action of which 
is weakened and eventually paralysed by the drug. Marrin and Emstry are, as we 
have seen, inclined to ascribe the fall—in a minor degree—partly to the dilatation 
which may be produced in the peripheral vessels by small doses of the drug, But 
since GASKELL and SHore have shown that the effect of chloroform is to excite the 
vasomotor centre in the medulla oblongata, and thus to cause contraction of the 
* Dixon, Jour. Phys., vol. xxx., p. 97, 1904. Also BRoprE and Dixon, zbid., p. 476. 
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