Influence of maternal periuterine and periovarian fat on reproductive performance and fetal growth in rats.

We aimed to evaluate how high-fat diet consumption can interfere with rat reproductive performance and fetal development. High-fat diet (HFD) was initiated in 30-day-old rats, distributed into two groups (n=7 animals/group): Rats receiving a standard diet and rats receiving HFD. At adulthood, the rats were mated, and on day 21 of pregnancy, the females were anesthetized, decapitated, and submitted to laparotomy to obtain visceral and periovarian adipose tissue. The uterine horns were exposed for analysis of maternal reproductive performance. The fetuses and placentas were weighed and analyzed. Pearson's correlation test was used, and p<0.05 was considered significant. There was a significant positive correlation (HFD consumption x increased periovarian fat) and a negative correlation with the implantation, live fetus numbers and lower litter weight. Furthermore, the increased relative weight of periuterine fat was related to the lower number of live fetuses and litter weight. Regarding the fetal weight classification, there was a negative correlation between the relative weight of periovarian fat and the percentage of fetuses appropriate for gestational age and large for gestational age. Therefore, our findings show that HFD maternal intake negatively influenced on reproductive performance and fetal growth.

Hyperglycemia influences the cell proliferation and death of the rat endocrine pancreas in the neonatal period.

AIMS: To evaluate the cell proliferation and death, and structural morphology of the pancreatic islet cells of the rats with hyperglycemia in the first month of life and compare to those of the control rats. MAIN METHODS: Female Sprague-Dawley newborn rats received Streptozotocin (a beta-cytotoxic drug) at birth for diabetes induction. Control and hyperglycemic animals were euthanized on different days of life: 5, 10, 15, and 30. The pancreas was collected and processed for immunohistochemical analysis of cleaved Caspase-3 (cell death), Ki-67 (cell proliferation), PDX-1 (transcription factor responsible for insulin synthesis), and endocrine hormones (insulin, glucagon, and somatostatin). KEY FINDINGS: Control females showed a higher percentage (%) of Ki-67-positive(+) cells on D10 and D15, a higher % of insulin+ and somatostatin+ cells on D15 and D30, a lower % of PDX-1+ cells on D10, and a higher % of glucagon+ cells on D10 and D30. Hyperglycemic females showed a lower % of Ki-67+ cells on D15, a higher % of cleaved Caspase-3+ cells on D15, and insulin+ cells on D15 and D30. In the comparison among the experimental groups, the hyperglycemic females showed an increased % of cleaved Caspase-3+ and Ki-67+ cells and a lower % of PDX-1+ cells. SIGNIFICANCE: This study enabled a better understanding of the abnormal pancreas development regarding cellular proliferation, apoptosis, and hormonal synthesis in the neonatal period. Thus, the pancreatic islets of hyperglycemic rats do not reestablish the normal endocrine cell population, and cellular apoptosis overcame the proliferative activity of these cells.

Assessment of Oxidative Stress Biomarkers in Rat Blood.

Redox status assessments are time-consuming, require a large volume of samples and great reagent amounts, and are not adequately described for methodological reproducibility. Here, the objective was to standardize redox balance determination, based on previously described spectrophotometric tests in pregnant rats, to improve precision, time dispensed, and the volume of samples and reagents, while maintaining accuracy and adequate cost benefits. This protocol summarizes oxidative stress markers, which focus on spectrophotometric tests for the assessment of thiobarbituric acid-reactive substances, reduced thiol groups, and hydrogen peroxide, as well as the antioxidant activity of superoxide dismutase, glutathione peroxidase, and catalase in washed erythrocyte and serum samples from full-term pregnant rats. For non-pregnant rats and other species, it is necessary to standardize these determinations, especially the sample volume. All measurements were normalized by the estimated protein concentrations in each sample. To establish optimum conditions for the reproducibility of the proposed methods, we describe all changes made in each assay's steps based on the reference method reassessed for the new standardizations. Furthermore, the calculations of the concentrations or activities of each marker are presented. Thus, we demonstrate that the analysis of serum samples is easier and faster, but it is impossible to detect catalase activity. Furthermore, the proposed methods can be applied for redox balance determination, especially using smaller reagent amounts and lower sample volumes in lesser time without losing accuracy, as is required in obtaining samples during rat pregnancy.

UV-Accelerated Synthesis of Gold Nanoparticle-Pluronic Nanocomposites for X-ray Computed Tomography Contrast Enhancement.

Eco-friendly chemical methods using FDA-approved Pluronic F127 (PLU) block copolymer have garnered much attention for simultaneously forming and stabilizing Au nanoparticles (AuNPs). Given the remarkable properties of AuNPs for usage in various fields, especially in biomedicine, we performed a systematic study to synthesize AuNP-PLU nanocomposites under optimized conditions using UV irradiation for accelerating the reaction. The use of UV irradiation at 254 nm resulted in several advantages over the control method conducted under ambient light (control). The AuNP-PLU-UV nanocomposite was produced six times faster, lasting 10 min, and exhibited lower size dispersion than the control. A set of experimental techniques was applied to determine the structure and morphology of the produced nanocomposites as affected by the UV irradiation. The MTT assay was conducted to estimate IC50 values of AuNP-PLU-UV in NIH 3T3 mouse embryonic fibroblasts, and the results suggest that the sample is more compatible with cells than control samples. Afterward, in vivo maternal and fetal toxicity assays were performed in rats to evaluate the effect of AuNP-PLU-UV formulation during pregnancy. Under the tested conditions, the treatment was found to be safe for the mother and fetus. As a proof of concept or application, the synthesized Au:PLU were tested as contrast agents with an X-ray computed tomography scan (X-ray CT).

Exposure to intrauterine diabetes and post-natal high-fat diet: Effects on the endocrine pancreas of adult rat female pups.

AIMS: To evaluate the morphological changes in the pancreatic islet cells of adult female pups born to diabetic rats and fed a high-fat diet. MAIN METHODS: Female Sprague-Dawley rats were distributed into four experimental groups (n = 10 animals/group): 1) female pups from non-diabetic dams and fed a standard diet (OC/SD), 2) female pups from non-diabetic dams and fed a high-fat (OC/HFD), 3) female pups from diabetic dams and fed a standard diet (OD/SD) and 4) female pups from diabetic dams and fed a high-fat diet (OD/HFD). In adulthood, the rats were submitted to the oral glucose tolerance test and later euthanized to collect the pancreas for the analysis of pancreatic islets. KEY FINDINGS: The OC/HFD and OD/SD groups showed an increased percentage of cells immunostained for insulin and a decreased percentage and intensity of staining for somatostatin. The OD/HFD group showed an increased percentage of cells immunostained for insulin and glucagon and a higher staining intensity for glucagon. There was a progressive increase in blood glucose in the OC/HFD, OD/SD, and OD/HFD groups. SIGNIFICANCE: The association between maternal diabetes and/or the administration of high-fat diet-induced changes in the pancreatic hormonal triad of female pups in adulthood. In turn, these changes in the pancreatic islets are not capable of causing decreased blood glucose in the offspring, contributing to the development of glucose intolerance in adulthood.