High Frequency Current Burns in Rats

Abstract

In a recent paper 1 attention was called to destructive histologic results produced in the small intestine of adult albino rats through the agency of high frequency currents. Certain comparisons were possible between these results and the type of duodenal ulceration observed in man and thought at one time to be a sequence of cutaneous burns. 2 The ulceration produced by high frequency currents was more extensive, however, and not restricted to the duodenum. Yet, Stengel 3 has called attention to the occasional presence of ulceration in the stomach and elsewhere in the intestine, complicating burns of the skin in man.

Certain experiments upon adult albino rats were repeated, utilizing high frequency current as detailed in the previous paper. Particular attention was given, however, to the problem of mucosal regeneration of the intestine. Repeated heatings on alternate days with the rats parallel to and between the plate electrodes, which were spaced 19 cm., gave the most constant histologic changes. The amperage remained 0.2 and the voltage 2000. The rat temperatures reached 41°C. after exposure of from one-half to 2 hours of raying.

The apices of the villi demonstrated the first pathologic change. This was of the nature of a coagulation necrosis and was most marked, first, in the epithelial lining cells but involved the stroma cells ultimately. Exfoliation of the epithelial cells was the rule, while vascular dilatation, leucocytosis, hemorrhages into the villi, subrnucosa and muscularis were the characteristic changes encountered. Pyknotic nuclei with fragmentation and degeneration of both nuclei and cells were likewise often encountered in the mucosa and submucosa, especially in the intestinal and duodenal glands. These microscopic features ordinarily extended, when the burning was severe, throughout the entire length of the small intestine. They have been observed, further, in the pyloric end of the stomach and throughout the large intestine as far as the rectum.