Perinatal exposure to low doses of glyphosate-based herbicide combined with a high-fat diet in adulthood causes changes in the jejunums of mice.

AIM: Exposure to pesticides and consumption of high-fat diets are widespread in society. Reports have shown that exposure to glyphosate and a high-fat diet can cause gastrointestinal disorders and increase susceptibility to obesity. Thus, this study evaluated the impacts of perinatal exposure to glyphosate followed by consumption of a high-fat diet in adulthood on the histology and morphometry of jejunums and enteric nervous system of C57BL/6 mice. MATERIAL AND METHODS: After mating, 20 C57BL/6 female mice were separated into a control group (CG) and a glyphosate group (GLY) that received water with 0.5% glyphosate. After the lactation period, some male offspring were randomly separated into CG-SD and GLY-SD (standard diet) groups or CG-HD and GLY-HD (high-fat diet) groups. After 12 weeks, jejunum samples were collected and submitted to histological analysis. KEY FINDINGS: Indirect exposure to glyphosate changed the morphometry of the intestinal wall, increased the proportion of intraepithelial lymphocytes (IELs) and goblet cells, and altered the area occupied by collagen fibers. The hyperlipidemic diet hypertrophied the jejunal total wall, total muscular and submucosal layers, decreased IELs, and increased the proportion of goblet cells. GLY-HD mice had shallower crypts, shorter villi, and less goblet cells and IELs than mice from GLY-SD group. GLY-HD also showed an increased number of neurons in myenteric and submucosal plexuses. Groups exposed to glyphosate and/or fed a high-fat diet had atrophied submucosal neurons. SIGNIFICANCE: This study suggests that perinatal glyphosate exposure combined with a high-fat diet in adulthood increases the risk of jejunum inflammation and dysfunction.

Bees, birds and yellow flowers: pollinator-dependent convergent evolution of UV patterns.

Colour is one of the most obvious advertisements of flowers, and occurs in a huge diversity among the angiosperms. Flower colour is responsible for attraction from a distance, whereas contrasting colour patterns within flowers aid orientation of flower visitors after approaching the flowers. Due to the striking differences in colour vision systems and neural processing across animal taxa, flower colours evoke specific behavioural responses by different flower visitors. We tested whether and how yellow flowers differ in their spectral reflectance depending on the main pollinator. We focused on bees and birds and examined whether the presence or absence of the widespread UV reflectance pattern of yellow flowers predicts the main pollinator. Most bee-pollinated flowers displayed a pattern with UV-absorbing centres and UV-reflecting peripheries, whereas the majority of bird-pollinated flowers are entirely UV- absorbing. In choice experiments we found that bees did not show consistent preferences for any colour or pattern types. However, all tested bee species made their first antennal contact preferably at the UV-absorbing area of the artificial flower, irrespective of its spatial position within the flower. The appearance of UV patterns within flowers is the main difference in spectral reflectance between yellow bee- and bird-pollinated flowers, and affects the foraging behaviour of flower visitors. The results support the hypothesis that flower colours and the visual capabilities of their efficient pollinators are adapted to each other.

Inferring sex and caste seasonality patterns in three species of bumblebees from southern Brazil using biological collections.

Biological collections may often be an important source of information about natural history, behavioral habits, and ecology as they contain samples of organisms collected in different places and moments in times. In here, we used museum specimens to examine how populations of three species of Bombus-Bombus bellicosus Smith, Bombus morio (Swederus), and Bombus pauloensis Friese-vary over time with respect to abundance and biomass of each sex and caste. The study included all specimens of these three bumblebee species deposited in the insect collection of the Federal University of Parana that were collected in eastern Paraná, in southern Brazil. Seasonality is most noticeable in the peak of queen activity (number of individuals in collections) in early spring, after dormancy during the winter. Queens then founded nests, and workers and males began to become more abundant during spring and summer. Worker abundance peaked at the end of summer and beginning of fall and may correspond to increasing activity for production of new males and gynes. Male abundance peaks are during the reproductive period. Thus, we show with these data and analyses that museum collections can be very useful tools to examine temporal and ecological processes. We recommend greater use of museum accessions to explore these kinds of patterns that may otherwise go unnoticed.

Chlorpropamide treatment restores the reduced carrageenan-induced paw edema and pleural exudate volume in diabetic rats.

OBJECTIVE AND DESIGN: Knowing that hyperglycemia is a hallmark of vascular dysfunction in diabetes and that neonatal streptozotocin-induced diabetic rats (n-STZ) present reduced inflammatory response, we decided to evaluate the effect of chlorpropamide-lowered blood glucose levels on carrageenan-induced rat paw edema and pleural exudate in n-STZ. MATERIALS: Diabetes was induced by STZ injection (160 mg/kg, ip) in neonates (2-day-old) Wistar rats. TREATMENT: n-STZ diabetic rats were treated with chlorpropamide (200mg/kg, 15d, by gavage) 8 weeks after STZ injection. METHODS: Carrageenan-induced paw edema and pleural exudate volumes were assessed concomitantly with peripheral and exudate leukocyte count. We also evaluated the expression of inducible nitric oxide synthase (iNOS) in lungs of all experimental groups. RESULTS: Chlorpropamide treatment improved glucose tolerance, beta-cell function (assessed by HOMA-beta), corrected paw edema, and pleural exudate volume in n-STZ. Neither leukocyte count nor iNOS expression were affected by diabetes or by chlorpropamide treatment. CONCLUSION: Chlorpropamide treatment by restoring beta-cell function, reducing blood sugar levels, and improving glucose tolerance might be contributing to the correction of the reduced inflammatory response tested as paw edema and pleural exudate in n-STZ diabetic rats.

Participation of endogenous corticosteroids in inflammatory response in type 2 streptozotocin diabetic rats.

The inflammatory response is decreased in diabetic animals. After adrenals removal this impaired response in type 2 diabetic rats evaluated by pleurisy and vascular permeability tests was restored. Our studies demonstrate that endogenous corticosteroids play a partial role in the impaired inflammatory response in type 2 streptozotocin diabetic rats.