Gastric sarcomata in rabbits induced by intramural implantation of 3-methylcholanthrene

Abstract

Different authors have a t t empted to induce s tomach adenocarc inoma in rodents, using polynuclear aromat ic hydrocarbonst) ,2) . These studies have shown tha t several factors hampered the product ion of gastric neoplasia. I V Y and his group adminis tered 3-methylcholanthrene per os to rabbi t s wi th induced gastric ulcer; in one exper iment during 3"5 to t 3 mon ths a) and in another, over periods up to 18 mon ths (one case for 3"3 years)A). Only at rophic gastr i t is and cystic changes in the mucosa were observed. The present communication deals wi th the local reaction of the gastric t issues to the carcinogen implanted behind the so-called "pro tec t ive mucous ba r r i e r " of the s tomach, over a period of 605 days. Seventeen male and 4 female domestic rabbi ts (Oryctolagus cuniculus L.) wi th an initial average body weight of 2t00 g. were used. Each animal received a single dose of 10 mg. of 3-methylcholanthrene crystals (MC) implanted into the subserosa and/or into the muscular is of the ventral wall of the gastric an t rum. The animals were necropsied 605 days after implanta t ion . Two, which died previously (~73 and 210days respectively) were also examined. The material removed at necropsy was fixed in 10 percent formalin; paraffin sections were stained by haematoxyl in-eosin and van Gieson's method and occasionally wi th Mayer 's mucicarmine. The results are summarized in the Table. The animal necropsled 210 days pos t implan ta t ion (No. t/3) showed in the deep mucosa a focus of proliferat ing epithelial cells t ha t had broken th rough the muscularis mucosae and contacted the submucosa. A slight lymphocyt ic reaction was seen surrounding the invasive cells. In this animal chronic hyper t rophic gastr i t is also was observed. In 3 females examined at 605 days, gastric t umour s appeared at the site of implantat ion. The first case (No. t/2) consisted of a voluminous pedunculated soft neoplasm of 8"5 • 5"5 • 5'0 cm. adhering distally to the liver. The cut surface showed abundan t haemorrhagic t issue and necrosis. Microscopically, this t u m o u r was made up of cells of different size and shape and of m a n y mult inucleated giant cells. Monstruous nuclei and atypical mitosis appeared. In certain areas, diffuse lymphocyte in f lammatory infiltrate was noted. T u m o u r ceils infil trated the muscular t issue of the s tomach. The diagnosis was pleomorphic sarcoma. The second case (No. t / t 8) was a soft neoplasm of 3"3 • 3'0 • 3"0cm. which showed, at section, massive haemorrhage and necrosis. Histologically, the picture was similar to the first case and there was infi l trat ion and destruct ion of bundles of the muscularis. I t was diagnosed as a pleomorphic sarcoma. This animal also showed chronic hyper t rophic gastritis. The third case (No. t/19) was a soft whi t ish t u m o u r of 2.2 x 1-8 • 1.4cm. The cut surface was homogeneous. Microscopically, it was composed of loosely arranged s tar-shaped cells wi th spheroid nuclei. Nuclear monstruosi t ies were numerous . The amorphous intercellular substance was very abundant , and mucicarmine positive. Neoplast ic cells infiltrated and destroyed the muscnlar is externa. The diagnosis was myxosarcoma. Although the origin of these sarcomata was uncertain it seemed highly possible t ha t the pleomorphic ones were originated f rbm the muscular t issue and the myxosa rcoma from the subserosal connective tissue. Another animal (No. 1/22) showed chronic a t rophic gastr i t is at 605 days. The results presented here show tha t the rabbit , like the mouse 5) and the rat6), can develop sa rcomata after MCt rea tment . In guinea pigs, in t out of 41 animals, we have found an in t ramural le iomyosarcoma of the s tomach which appeared around the carcinogen crystais at 515 days postimplanta t ion 7). Table. Gastric lesions in/emale rabbits induced by intramural in~planration of 3-methylcholanthrene

DOI: 10.1007/BF00592840

Cite this paper

@article{Zaldvar2004GastricSI, title={Gastric sarcomata in rabbits induced by intramural implantation of 3-methylcholanthrene}, author={R. S. d. Zald{\'i}var and Ceaser Aliaga and Hilda Maria Rodriguez}, journal={Naturwissenschaften}, year={2004}, volume={48}, pages={672-672} }