On the action of sodium chloride in the prevention of proteotoxin shock

It was shown by Friedberger and Hartoch that guinea-pigs could be protected against anaphylactic shock by an intravenous injection of hypertonic salt solution immediately preceding the toxic dose of antigen. That this protection is not due, as Friedberger and Hartoch claimed, to the inhibitory action of the salt on the alexin was demonstrated by Ritz, who found that an injection of salt also exerted protective action in animals injected with proteotoxins (the anaphylatoxins of Friedberger).

Dale concluded that the protection afforded by sodium chloride against acute anaphylaxis was due to the decreased irritability of the smooth muscle. He found that if the uterus of a sensitized guinea-pig were suspended in hypertonic salt solution, the addition of the antigen no longer caused the usual anaphylactic reaction. Other stimulating substances, like pilocarpine and pituitary extract, also failed to produce their typical stimulation provided that the uterus was bathed in hypertonic salt solution.

It is the object of the present investigation to show that, when a preliminary injection of salt protects against proteotoxin shock, the absence of reaction is due to the lessened irritability of smooth muscle.

In the first place, it was necessary to confirm, if possible, the observations of Ritz. It must be remembered that, as Friedberger and Hartoch pointed out, the protective action of salt is a limited one and if the amount of antigen given at the second injection or if the amount of proteotoxin used is much above the minimal fatal dose, the poisoning is so acute and powerful that the protective effects of the salt are entirely masked. We had considerable difficulty at first in obtaining satisfactory experiments because of our failure to appreciate this relation, but when the toxic dose did not materially exceed the minimal fatal dose there was no difficulty in determining the protective effect of salt in guinea-pigs injected with proteotoxin.