Abstract
Kendall 1 has shown recently that formaldehyde will reduce smooth muscle contraction that has been initiated by histamin and by a histamin-like substance obtained in filtrates from cultures of B. welchi. Inasmuch as one theory of smooth muscle contraction induced by anaphylaxis postulates the liberation of some substance resembling histamin, the effect of formaldehyde on such contraction was studied.
Female guinea pigs weighing about 250 gm. were injected intraperitoneally with 0.2 cc. of a 1 to 10 dilution of eggwhite solution and were tested two to three weeks thereafter. Others were injected by passive transfer of a potent anti-eggwhite rabbit serum, and tested twenty-four hours later. After each animal had been killed by a blow on the head, the two uterine horns, or two apparently equal intestinal strips were suspended each in a separate bath of a Dale apparatus. This contained 150 cc. of Tyrode solution kept at a temperature of 38° C. and through which free oxygen was passed. One muscle segment served as a control, and the other was tested to the action of formaldehyde.
Experiment I. 0.5 cc. of a 1 to 10 eggwhite solution was added to each of the two baths simultaneously. The second bath had been treated previously with 0.2 cc. of neutral formalin solution (final concentration of formaldehyde about 1 to 2600). In animals that proved to be sensitive, the muscle strip contracted characteristically on the addition of egg white to the first bath, and this was recorded on a kymograph. The strip in the second bath did not contract. This bath was then emptied and eggwhite again added to fresh Tyrode's solution. No contraction occurred, and thus desensitization was simulated. On again emptying the bath, refilling with Tyrode's solution and then adding histamin, an immediate violent contraction occurred to this stimulant. This indicated that formaldehyde had not impaired the contractility of the muscle.
Get full access to this article
View all access options for this article.