The effect of bombardment with continuous infrared laser on the ultrastructure and proliferation of Ehrlich carcinoma cells

Abstract

Bombardment of Ehrlich carcinoma with infrared laser for 3-5 min daffy during a 10-day period resulted in an almost 2-fold increase in the index of labeled nuclei without any increase in mitotic index and tumor mass. The differences between the index of labeled nuclei and mitotic index revealed by electron microscopy are due to pronounced changes in the nuclei: "squeezing" of chromatin through pores or ruptures in the nuclear membrane and its random location in the cytoplasm. The number of macrophages, neutrophils, and plasma cells in the tumor increases. Key Words: laser; Ehrlich carcinoma; ultrastructure; proliferationAlthough low-intensity laser irradiation, particularly in the infrared and red range, has been widely used to treat numerous pathological processes and states [1][2][3][4][5]9] and to stimulate the immune system in patients with tumors [7], its effect on tumor cells has not been studied in sufficient detail. Specifically, the effect of continuous low-intensity infrared (IR) laser on the ultrastructure and proliferation of tumor cells has not been investigated.Our aim was to study the effect of repeated bombardment of low-intensity IR laser on the structure and proliferation of Ehrlich carcinoma cells. MATERIALS AND METHODSA total of 32 outbred albino mice were used. Irradiation (3 and 5 min once daily at 9 a.m.) was started on day 7 after tumor induction. The output of the arsenide-gaUium laser (Aura) was 180-200 mW. The distance between tumor and laser was not more than 0.5 cm. Tumor morphology was studied prior to irradiation and on days 5 and 10 after it was begun. Control tumors were not irradiated. For the Laboratory of Pathological Anatomy, V. Vakhidov Surgery Research Center, Tashkent, Uzbekistan determination of proliferative activity 3H-thymidine (18 rtBq/g body weight) was injected intraperitoneally 1 h before decapitation.Sections (4-5 ~t thick) were covered with "M" emulsion, exposed for 1 month, and developed in an amidol developer. The sections were stained with Ehrlich hematoxylin, and the index of labeled nuclei (ILN) was determined. A minimum of 5000 nuclei were counted in each group, and at least 10,000 cells were counted upon morphometric determination of the mitotic index (MI). For electron microscopy the tissue was fixed with 2,5% glutaraldehyde and postfged with 1% OsO 4 in phosphate buffer. Double-contrasted Epon-Araldite ultrathin sections were studied in a Hitachi-H600 electron microscope. Semithin sections were stained with Methylene Blue and fuchsin.Data on tumor mass and morphology were processed by the methods of variational statistics using dedicated software. RESULTSOn day 7 after tumor induction a round, dense formarion about 0.5 cm in diameter was found in the inguinal region.