Morphological, morphometric and histochemical analysis of the large intestine of rabbits intoxicated with Solanum glaucophyllum (duraznillo blanco).

ZANUZZI CN, BARBEITO CG, ORTIZ ML, FONTANA PA, PORTIANSKY EL, GIMENO EJ.

João Pessoa, Paraiba Brasil

Congreso; ISOPP8 (International Symposium in Poisonous Plants). João Pessoa, Paraiba Brasil, 4 al 8-05-2009; 2009

Solanum glaucophyllum (synonym S. malacoxylon) is a calcinogenic plant responsible for the enzootic calcinosis of ruminants in South America, a disease that causes considerable economic losses in Argentina, Brazil and Uruguay In the intestine, vitamin D enhances the efficiency to absorb dietary calcium and phosphate In addition, vitamin D is a key regulator of gastrointestinal homeostasis. It participates in the processes of intestinal epithelium differentiation. We analysed the morphological and morphometric modifications as well as the histochemical and lectinhistochemical carbohydrate pattern in the colon and rectum of rabbits intoxicated with S. glaucophyllum.Twenty-five-three-month old New Zealand male rabbits were used. Ten animals were experimentally intoxicated per os with 125 mg/animal of powdered Sg leaves twice a week until they were killed. Five of them were killed fifteen days after the beginning of the intoxication (I-1515 group), whereas the other five were left for other fifteen days (I-3030 group). Five more animals were intoxicated for 15 days but killed after forty-five days (possibly recovered group-PRG1545). Two nutritionally restricted groups (NRG) were used to determine the influence of an anorexia state. Colon and rectum lamina propria and submucosa of both intoxicated groups appeared moderately hypercellular, oedematous, with lymphangiectasia which in more severe cases extended up to the muscular layer. The infiltration consisted of mononuclear cells, such as macrophages, lymphocytes and plasmocytes. Colonic wall appeared thinner in both intoxicated groups in comparison with control animals. The colon and rectum sections of some PRG and some animals from both NRG showed a morphological pattern similar to that of controls, whereas others resembled the described for the intoxicated animals.  In the colon of both intoxicated animals the most remarkable changes were observed in the parameters of the crypts of the PRG, since the area, perimeter, length and width significantly increased. Neither the thickness of the intestinal wall nor muscular layer was significantly affected between experimental groups. In the rectum the area, perimeter and length of crypts were slightly reduced in I1515 group and both NRG, but the change was not statistically significant. Values for the thickness of mucosa-submucosa layer, considered as a whole, were significantly decreased in I1515 animals, whereas intermediate values between control and I1515 group were present in the PRG and both NRG.  Neither PAS nor AB techniques showed differences between the studied groups. The lectin histochemical study revealed differences in the carbohydrate composition of both intestinal sections. There was a reduction in DBA binding to the glycocalix of the surface and crypt epithelium of the colon and rectum of both intoxicated groups. Our results showed different morphological and histochemical changes in the colon and rectum in response to S. glaucophyllum intoxication. In this work we described histopathologycal and morphometrical changes on intestines under Sg intoxication. The modifications on the glycosilation pattern may attribute a new role for vitamin D as a regulator of the intestinal glycosilation. Future studies on cell proliferation and death process will help to understand the morphological changes described.