Exploring porcine kidney explants as a model for the study of nephrotoxins and the therapeutic potential of phytic acid.

The use of in vivo models to assess nephrotoxicity has faced ethical limitations. A viable alternative is the ex vivo model that combines the 3 R principles with the preservation of tissue histology. Here, we established a gentamicin nephrotoxicity model using pigs` kidney explants and investigated the effect of phytic acid (IP6) against gentamicin- induced nephrotoxicity. A total of 360 kidney explants were divided into control, gentamicin (10 mM), IP6 (5 mM), and gentamicin+IP6 groups. The activity of gammaglutamyltransferase (GGT), creatinine levels, histological assessment, oxidative stress, and inflammatory cytokine expression were analyzed. Exposure to gentamicin induced an increase in GGT activity, creatinine levels, lesion score, lipoperoxidation and IL-8 expression. Explants exposed to IP6 remained like the control. The addition of IP6 to gentamicin prevented tissue damage, increasing the antioxidant status and gene expression of IL-10. This model proved to be an adequate experimental approach for identifying nephrotoxins and potential products to modulate the toxicity.

Animal performance and biochemical parameters are sex-dependent in peripubertal rats exposed to deoxynivalenol.

Deoxynivalenol (DON), a mycotoxin produced mainly by Fusarium graminearum and F. culmorum commonly contaminates food commodities across the globe. Due to this, exposure to DON might pose potential health hazards to humans and animals. Biological factors like sex and age can influence the toxicity of DON. However, in toxicological studies involving DON, the sex and age-dependent response has been often overlooked. Thereby, the objective of this study was to evaluate if sex differences are evident in DON's systemic effects in peripubertal rats. Juvenile animals (n = 24) with 28 days postnatal day were randomly assigned to two experimental groups: Control group (n = 12, 6 females and 6 males, mycotoxin-free diet) and DON group (n = 12, 6 females and 6 males, diet containing 10 mg DON/kg of feed). During 28 days of treatment, the animals were weighed weekly and body weight gain and food intake were calculated for each week. After the experimental period, blood samples, intestine, liver, and kidney were collected and destined for biochemical, hematological, histopathological, and oxidative stress analyses. Greater anorectic responses were seen in males, while only females showed increased levels of creatinine and triglycerides. Regardless of sex, DON induces an increased number of white blood cells, particularly lymphocytes and a significant reduction in the levels of hemoglobin, hematocrit, mean corpuscular hemoglobin, and neutrophils. In males and females fed a DON-contaminated diet, histological lesions were observed in the intestine, liver, and kidney. Ingestion of DON induced a significant increase in the antioxidant potential in the intestine, liver, and kidney. However, this effect was not able to prevent oxidative stress in the renal tissue. Taken together, our results showed a sex-related response in food intake, weight gain, and biochemical parameters in rats exposed to DON during the juvenile and peripubertal periods. In addition, we have verified that oxidative stress is an important mechanism in the nephrotoxicity of DON.

Effects of chito-oligosaccharide on piglet jejunal explants: an histological approach.

Antibiotics have been widely used in piglet diets to promote growth performance and reduce diarrhea incidence. However, the resistance of pathogens to antibiotics and the risk of residues of antibiotics in animal products induced a growing interest in the use of alternatives to in-feed antibiotics. Chito-oligosaccharide (COS), a natural alkaline polymer of glucosamine is currently being tested as a substitute for in-feed antibiotics. In weaned piglets, COS has positive effects on promoting growth, which may be related to its action on intestinal morphology, immune ability and beneficial microbiota. However, previous studies shown variable results with effective doses ranging from 30 mg/kg to 5 g/kg. Therefore, the goal of this study was to test the hypothesis that the use of COS can be an alternative to in-feed antibiotics by improve the intestinal morphology of piglets, using the jejunal explant model. The intestinal explants were exposed for 4 h to following treatments: control - only culture media and culture media with COS in doses of 0.025 mg/ml, 0.05 mg/ml, 0.1 mg/ml and 0.15 mg/ml. After the incubation period the explants were processed for histological and morphometrical analysis. The histological changes were evaluated using an adapted histological score based on the intensity and severity of lesions. Mild histological changes were observed in jejunal explants exposed to different treatments; however, no significant difference in the histological score, villi height, crypt depth or villus : crypt ratio were observed between the COS-groups and the control. In addition, goblet cells density in intestinal explants exposed to COS remained statistically similar to control group. Our results indicate that COS exposure in levels ranging from 0.025 to 0.15 mg/ml induced no effect on intestinal morphology of pig's explants. The research will provide guidance on the low dosage of COS supplementation on weaning pigs.

Influence of follicle-stimulating hormone concentrations on the integrity and development of bovine follicles cultured in vitro.

SummaryThis study investigated the in vitro culture of bovine follicles included in ovarian tissue for 2 or 6 days (D2 or D6), with the addition of different concentrations of follicle-stimulating hormone (FSH) (0, 10, 50, 100 or 200 ng/ml). Data were compared for follicular development, morphological integrity and diameter of follicles and oocytes. Ovaries (n = 10) from Nelore cows (n = 5) were divided into fragments (n = 11 per ovary) and were immediately fixed in Bouin's solution (D0) or were individually cultured for 2 or 6 days in one of the described concentrations of FSH and then processed for histology. Compared with the rates of follicular development at D2 for minimal essential medium (MEM) (75.0%) and 50 ng/ml of FSH (71.1%), the best rates of follicular development at D2 were obtained with 10 (84.7%), 100 (87.5%) and 200 ng/ml of FSH (85.0%; P<0.05). After 6 days of cultivation, there were no differences among treatments regarding follicular growth. The morphological integrity of preantral follicles was better maintained by 100 ng/ml FSH for 2 and 6 days of cultivation (51.2 and 40.4%, respectively; P<0.05) than that for MEM (D2: 30.9%, D6: 20.8%), 10 (D2: 39.2%, D6: 22.8%), 50 (D2: 30.4%, D6: 28.8%) and 200 ng/ml FSH (D2: 45.2%, D6: 36.8%). FSH at 100 ng/ml provided the highest mean diameter averages: 34.5±10.8 µm at D2 and 33.2±12.5 µm at D6 (P<0.05). We concluded that the medium supplemented with 100 ng/ml FSH during in vitro culture provided appropriate conditions for the development and morphological integrity of preantral follicles in cattle.