Creatine supplementation in trained rats causes changes in myenteric neurons and intestinal wall morphometry

Creatine is widely used by athletes as an ergogenic resource. The aim of this study was to evaluate the influence of creatine supplementation on the duodenum of rats submitted to physical training. The number and myenteric neuronal cell bodies as well mucosal and muscular tunic morphometry were evaluated. Control animals received a standard chow for 8 weeks, and the treated ones received the standard chow for 4 weeks and were later fed with the same chow but added with 2% creatine. Animals were divided in groups: sedentary, sedentary supplemented with creatine, trained and trained supplemented with creatine. The training consisted in treadmill running for 8 weeks. Duodenal samples were either processed for whole mount preparations or for paraffin embedding and hematoxylin-eosin staining for histological and morpho metric studies of the mucosa, the muscular tunic and myenteric neurons. It was observed that neither creatine nor physical training alone promoted alterations in muscular tunic thickness, villus height or crypts depth, however, a reduction in these parameters was observed when both were associated. The number of myenteric neurons was unchanged, but the neuronal cell body area was reduced in trained animals but not when training and creatine was associated, suggesting a neuroprotector role of this substance.

Toxic thermoresistant metabolites of Fusarium oxysporum are capable of inducing histopathological alterations in Wistar rats

The genus Fusarium is known to produce mycotoxins that cause fusariosis in plants, animals and humans. Mycotoxins are among the virulence factors of this genus. Metabolic extracts of Fusarium oxysporum, isolated from a patient with onychomycosis and sterilized by filtration or autoclave, were inoculated intradermally into Wistar rats at concentrations of 0.25, 0.5 and 1 µg/µL, and the effects on their tegument were observed at 24 and 72 hours. After histological procedures and staining by hematoxylineosin, the sections were studied for their inflammatory-reaction intensity and for evidence of injury and tissue distortion. Inflammatory reactions in the dermis and the subcutaneous tissue were observed at all concentrations of the inoculated extract tested. There was a significant influx of neutrophils, mastocytes and lymphocytes, as well as a large quantity of macrophages. Apoptotic bodies and hyperemic blood vessels were observed. This reaction was directly related to the extract concentration, and was most intense in animals that received the 1 mg/µL dose. The maximum peak was observed at 24 hours. The autoclaved metabolic extract produced the same effects as the untreated one, indicating the presence of heat-resistant metabolites. In conclusion, the metabolic extracts obtained from sterilized culture filtrates of F. oxysporum are capable of inducing an inflammatory response within 24 hours in the dermis and subcutaneous tissue of rats.(AU)

Goblet cell number in the ileum of rats denervated during suckling and weaning

The enteric nervous system plays a role on the stimulation of secretory cells of intestinal epithelia. We have demonstrated that ablation of ENS stimulates epithelial cell proliferation. As goblet cells are important constituents of the epithelial sheet, it is mandatory to investigate separately this cell type. The myenteric plexus of the ileum of rats in postnatal development was partially removed by the serosal application of benzalkonium chloride (BAC). Three groups of animals were used: those where BAC application was at 13 days and sacrifice was at 15 (13/28-day-old) or 23 days after treatment (13/36-day-old), and those where BAC was applied at 21 days and rats were killed 15 days after treatment (21/36-day-old) . The number of goblet cells in the ileum was estimated in sections stained by periodic acid-Schiff (PAS) histochemistry. In the 13/28 and 21/36 groups, the number of goblet cells was significantly higher after BAC treatment. These results suggest that the myenteric denervation may have an acute effect on the number of goblet cell in suckling and weanling rats, probably through submucous plexus.