SCANNING ELECTRON MICROSCOPIC STUDIES OF THE SMALL INTESTINAL VILLI IN MICE: Exposure to Various Surfactants

"Scanning electron microscopic studies of the intestinal mucosa have been reported by several authors. However, few of them gave any fine ultrastructure of the surface, because the established methdology was not available for them to remove mucus. The small intestinal mucosa had been observed with the treatment of Pluronic F68. By improving this method, ultrasturcture of the surface were exposed and it resulted in obtaining successful clearer observations. BRIJ 35 and Tween 80 were examined for mucus-removing action of the small intestine by scanning electron microscope (SEM). These 3 surfactants were selected according to the results of Yonezawa's "Light microscopic studies of the small intestina. mucosa exposed to various surfactants." Each of the surfactants was injected into the intestine of ddY-strain mice after laparotomy. After the defined time parts of intestine were removed, washed by physiological saline, and prepared for SEM specimens. The specimens were examined with the field emission type o the Hitachi S-700 scanning electron microscope. Conclusions are: 1. The action as "injury" to the intestine was observed most conspicuously in BRIJ 35, and most slightly in Tween 80. The "detergent effect" was most remarkable in Pluronic F68 which injured slightly to the small intestinal mucosa. That is, it was found that a Pluronic F68 pretreatment of the intestine provides a very effective result to remove mucus. 2. The concentration of it was critical, and 5% Pluronic F68 gave fine ultrastructurew of the small intestinal mucosa, and it made capable for successful clear observations. It is expected that this surfactant will be used for their broad application of SEM investigations.