Reduced Liver Lipid Peroxidation in Subcellular Fractions Is Associated with a Hypometabolic State in Rats with Portacaval Anastomosis.

A surgical connection between portal and inferior cava veins was performed to generate an experimental model of high circulating ammonium and hepatic hypofunctioning. After 13 weeks of portacaval anastomosis (PCA), hyperammonemia and shrinkage in the liver were observed. Low glycemic levels accompanied by elevated levels of serum alanine aminotransferase were recorded. However, the activity of serum aspartate aminotransferase was reduced, without change in circulating urea. Histological and ultrastructural observations revealed ongoing vascularization and alterations in the hepatocyte nucleus (reduced diameter with indentations), fewer mitochondria, and numerous ribosomes in the endoplasmic reticulum. High activity of hepatic caspase-3 suggested apoptosis. PCA promoted a marked reduction in lipid peroxidation determined by TBARs in liver homogenate but specially in the mitochondrial and microsomal fractions. The reduced lipoperoxidative activity was also detected in assays supplemented with Fe2+. Only discreet changes were observed in conjugated dienes. Fluorescent probes showed significant attenuation in mitochondrial membrane potential, reactive oxygen species (ROS), and calcium content. Rats with PCA also showed reduced food intake and decreased energy expenditure through indirect calorimetry by measuring oxygen consumption with an open-flow respirometric system. We conclude that experimental PCA promotes an angiogenic state in the liver to confront the altered blood flow by reducing the prooxidant reactions associated with lower metabolic rate, along with significant reduction of mitochondrial content, but without a clear hepatic dysfunction.

Effects of intragastrically-administered Tepary bean lectins on digestive and immune organs: Preclinical evaluation.

Previous work showed that Tepary bean (Phaseolus acutifolius) lectins exhibit differential cytotoxic effects on cancer cell lines by apoptosis induction. In vivo studies using a Tepary bean lectin fraction (TBLF, 50 mg/kg of body weight) after colon cancer induction in rats showed that TBLF inhibited early precancerous lesions without systemic toxicity however, loss of body weight gain and activation of immune cells were observed. In order to know more about the possible adverse effects, we evaluated the administration of TBLF on digestive and immune organs. Sprague Dawley rats were administered TBLF for six weeks and allowed to recover for two weeks. Immune activation was observed through an increased lymphocyte-granulocyte ratio, an increased number of lymphoid follicles in intestinal Peyer's patches and a slight expansion of the splenic white pulp. Atrophy was observed in small intestine villi and crypt foci of the colon without normalization after the recovery period. Pancreas histopathology showed hypertrophy after the six-week administration period, particularly vacuolation and trabecular widening; but after the two-week recovery period atrophy was observed, suggesting a partial compensatory type process. Our results show that TBLF activates the immune system and affects digestive organs through direct interaction with intestinal epithelium, and indirectly by producing pancreatic hyperfunction. Further work will focus in longer recuperation periods after TBLF treatment.

Gray fox (Urocyon cinereoargenteus) parasite diversity in central Mexico.

Mexico has a long history of parasitological studies in communities of vertebrates. However, the mega diversity of the country makes fauna inventories an ongoing priority. Presently, there is little published on the parasite fauna of gray foxes (Urocyon cinereoargenteus Schereber, 1775) and this study provides new records of parasites for gray foxes in central Mexico. It is a continuation of a series of previous parasitological studies conducted with this carnivore in Mexico from 2003 to the present. A total of 24 foxes in the Parque Nacional El Cimatario (PANEC) were trapped, anaesthetized, and parasites recovered. The species found were Dirofilaria immitis, Ctenocephalides canis, C. felis, Euhoplopsillus glacialis affinis (first report for gray foxes in Mexico) Pulex simulants, and Ixodes sp. Three additional gray fox carcasses were necropsied and the parasites collected were adult nematodes Physaloptera praeputialis and Toxocara canis. The intensive study of the gray fox population selected for the 2013-2015 recent period allowed for a two-fold increase in the number of parasite species recorded for this carnivore since 2003 (nine to 18 parasite species), mainly recording parasitic arthropods, Dirofilaria immitis filariae and adult nematodes. The parasite species recorded are generalists that can survive in anthropic environments; which is characteristic of the present ecological scenario in central Mexico. The close proximity of the PANEC to the city of Santiago de Queretaro suggests possible parasite transmission between the foxes and domestic and feral dogs. Furthermore, packs of feral dogs in the PANEC might have altered habitat use by foxes, with possible impacts on transmission.