Effect of oral phytohaemagglutinin intake on cell adaptation in the epithelium of the small intestine of the rat.

The effect of phytohaemagglutinin (PHA) on the adaptation of the proximal jejunal epithelium and on the distal ileal epithelium was studied in rats. The group receiving PHA gained less weight than controls, and the enterocyte population of their jejunal villi, as well as the morphokinetic parameters (length, population, crypt cell production per crypt) of their jejunal and ileal crypts were higher than those of the controls. The proximal lesion caused by PHA (reduction of villus cell populations) stimulates hyperplasia of the crypt-villus unit of the ileal epithelium with the development of adaptation from afar. These adaptations occurred in animals that ingested PHA even in the presence of severe malnutrition.

[Effect of phytohemagglutinins on cell proliferation of the small intestine epithelium of rats]. / Efeito da fitohemaglutinina na proliferação celular do epitélio do intestino delgado de ratos.

Twenty male rats, were divided into two groups of ten animals each: E group, which received solid diet containing 4% of phytohemagglutinin and P group iso-caloric par-fed control, which received the same diet but the phytohemagglutinin was inactivated by heat. Water was offered ad libitum to all groups. The animals were weighed every day and the consumption of diet and water was registered. In the fourteenth day of experiment, the animals were sacrificed and the fragments of jejunum and ileum were removed to morphokinetic study. The results showed that the hydric ingestion was the same in both groups, the body weight of the E group was significant smaller than P group, the villus cell population from the jejunum of the E group was statistically smaller than P group and the contrary happened with ileum samples, wherein the E group was statistically larger than P. The jejunum villus height from E group was similar with P group, but in the ileum of the E group was larger than P. The depth, the cell population and cell production rate of crypt of E group were larger than P, in the jejunum and in the ileum. In conclusion, these results in the present study supply evidence that the intake of the phytohemagglutinin provokes injury of jejunal mucosa, reducing the villus cell population and stimulating the crypt hyperplasia, developing local adaptation. This adaptative model is similar to the one that occurs in celic disease. This proximal lesion stimulate crypt-villus unit hyperplasia of the ileal epithelium, developing distal adaptation. These adaptations occurred in animals that ingested phytohemagglutinin, even though with multicarencial malnutrition.