Morphological Effects of Intraperitoneal Oily Fatty Acids on the Intestine and Peritoneum of Rats

Abstract

Changes of the mucosa of the small intestine in animal experiments can be produced by a variety of methods. The direct application of numerous chemical agents on the epithelium of the mucosa and parenteral administration of cytostatics as well as an indirect damage by experimental intestinal lymphatic obstruction lead to mucosal lesions with atrophy of the villi. Our paper presents a simple indirect method for induction of structural mucosa changes in rats using experimentally produced peritoneal alterations as a precursor. The first experimental group with 108 male wistar rats was divided into 5 subgroups and treated as follows: 43 rats got continuous daily intraperitoneal injections of 3-3 ml/kg body weight sesame oil DAB 6 which contains 50% oleic acid, 36% linolic acid, 1% free fatty acids, 0.1% lecithin and portions of stearic, palmitic and arachic acid; 6 rats got 6.6 ml sesame oil per kg i.p., 43 animals received daily doses of 3-3 ml oil/kg per orally by a pharyngeal tube, 6 rats of each group were sacrificed after 68 and 92 days, all the rest were killed after 100 days of continuous daily treatment. Aortic blood was used for determination of the total cholesterol serum concentration. Blocks of tissue of every organ were fixed in 4% formalin, sections were stained with hematoxylin and eosin, hematoxylin-sudan and by the periodic acid Schiff (PAS-) method. For the purpose of autoradiographic determination of the 3H-thymidine labelling index the rats were administered i.p. 2 mCi 3H-thymidine/kg 40 minutes prior to death. Autoradiographs were prepared from sections of the small intestine by using liquid photoemulsion Ilford K5. In the second experimental group 7 rats got a single i.p. injection of 5 ml, 5 rats of the 10 ml and 9 rats of 20 ml sesame oil per animal; 4 rats were administered 8 ml daily for 5 days...