Prevention of Proteotoxin Shock. 207 



tractions of certain smooth muscle groups occur. The experiments 

 of Schultz, Dale, Weil, and others, have pointed to a definite 

 parallelism between the irritability of smooth muscle and the 

 condition of sensitiveness. Furthermore, Dale has shown that 

 a hypertonic salt solution prevents the usual reaction of the uterus 

 of a sensitized guinea-pig to antigen. It was therefore necessary 

 for us to determine whether an increase in the tonicity of the fluid 

 bathing the uterus would abolish the reaction of the organ to pro- 

 teotoxin. In our experiments the uteri of virgin guinea-pigs were 

 used. The animals were etherized and exsanguinated. The 

 uterus was excised and one horn was suspended in a glass cylinder 

 in such a manner that its contractions would be recorded on the 

 smoked paper of a slowly moving kymograph. 



On adding a little fresh guinea-pig serum to the Ringer's 

 solution in which a uterus is suspended a powerful contraction 

 immediately ensues. If a small amount of salt solution is now 

 added a total inhibition of the uterine movements occurs and the 

 organ slowly relaxes. On replacing this mixture with pure fresh 

 Ringer's fluid the normal rhythm and tonus usually return. When 

 serum and salt solution are added together no contraction occurs. 



Similar changes take place when proteotoxin is added to the 

 Ringer's solution bathing the uterus. The spasm which follows 

 such an addition may be removed by the subsequent addition of 

 enough salt to approximate the concentration likely to be found 

 in a guinea-pig of 200 gm. after the injection of 1.5 c.c. of 30 per 

 cent, sodium chloride. If the uterus is surrounded by such a 

 hypertonic salt solution the addition of proteotoxin fails to produce 

 a typical spasm. 



Occasionally a powerful contraction occurs after washing a 

 preparation which because of the presence of excess salt has not 

 reacted to proteotoxin. The explanation of this late spasm seems 

 to be as follows: When the proteotoxin-salt mixture is siphoned 

 away a trace of the mixture remains in the vessel. When the pure 

 Ringer's solution is run in the original mixture is greatly diluted. 

 The small amount of proteotoxin still remaining is sufficient to 

 send the uterus into spasm because the quantity of salt remaining 

 is insufficient to lower the irritability of the muscle. 



In these experiments it is apparent that in the presence of a 



