Impact of benzophenone-3 on the integument and gills of zebrafish (Danio rerio).

Benzophenone (BP-3) is an organic compound that is a common ingredient in lotions, conditioners, and other personal care products, which helps protect against ultraviolet radiation. This study investigated the effect of BP-3 on the structure of the integument and gills, as well as the activities of superoxide dismutase (SOD) and catalase (CAT) in the gills of Danio rerio. Fish were exposed to different concentrations (7, 70, and 700 µg L-1) of BP-3 for 7 and 14 d. For the histological analysis of the integument and gills, the fish were fixed in Bouin liquid and processed according to standard histologic procedures, and the tissue section slices were stained according to different histochemical methods. BP-3 caused tissue damage and morphological alterations in the gills; however, the integument showed no histological or morphological alterations. Furthermore, there was no observed correlation between the BP-3 concentration and exposure period and the gill alterations, as these did not occur in a linear manner. The gills were removed to evaluate the antioxidant defense; for this, CAT and SOD activities were measured, and a reduction of SOD activity was noted, whereas the CAT activity was not significantly affected.

Beneficial effects of Ilex paraguariensis in the prevention of obesity-associated metabolic disorders in mice.

Obesity is a chronic condition involving inflammation and oxidative stress that commonly predisposes affected individuals to develop metabolic disorders. We hypothesize that Ilex paraguariensis (IP) can modulate oxidative stress and inflammation underpinning metabolic disorders caused by obesity. C57BL/6 mice were fed a high-fat diet (HFD group) for 12 weeks. Concomitantly, some mice were treated with roasted IP (15 mg/ml - HFD + IP) or dimethyl fumarate (DMF) as a positive control (2 mg/ml - HFD + DMF). The control group received standard chow and water ad libitum. Histological analyses of fat tissue and liver, and quantification of mediators related to oxidative stress (Kelch-like ECH-associated protein 1/NF-E2-related factor 2, NADP(H) quinone oxidoreductase-1 [NQO1], heme oxygenase 1 [HO1], and superoxide dismutase) as well as metabolic profile blood biomarkers (glucose, leptin, resistin, high-density lipoproteins [HDLs], and triglycerides) were performed. Metabolic disorders were prevented in mice treated with IP, as evidenced by the observation that glucose, HDL, and resistin levels were similar to those assessed in the control group. Morphological analyses showed that both IP and DMF treatments prevented hepatic steatosis and adipocyte hypertrophy in visceral adipose tissue. Finally, although the antioxidant response stimulated by IP was quite limited, significant effects were found on NQO1 and HO1 expression. In conclusion, IP has promising preventative effects on the development of metabolic disorders caused by obesity.

Effect of benzophenone-3 on the blood cells of zebrafish (Danio rerio).

Benzophenone-3 (BP-3) is a common component of organic sunscreen widely used that can affect especially aquatic ecosystems health, including fish. To verify the biological effects of low concentrations of BP-3 on blood cells, one hundred and forty zebrafish (D. rerio) were used and then randomly divided into five groups: control group (water), solvent group (alcoholic water), and BP-3 group (BP-3 at 7 µg L-1, BP-3 at 70 µg L-1, and BP-3 at 700 µg L-1). The blood slices were stained with Panoptic stain and with Giemsa solution for the hematological analysis. During the exposure to BP-3, no behavioral changes were observed. Although no significant difference in total leukocytes occurred, an increase in neutrophils and a reduction of lymphocytes at the highest concentration on both 7th and 14th days were detected. The total and cytoplasmic area of erythrocytes on the 7th day at the highest concentration were reduced. In addition, alterations on the erythrocyte nuclear morphology in fish exposed to BP-3 were usually visualized, mainly when considered the occurrence of blebbed nucleus and micronucleus, indicating that BP-3 exhibits cytotoxic and mutagenic effects. The results indicate that BP-3 can interfere with the morphophysiology of aquatic organisms.

Effects of titanium dioxide nanoparticles on the intestine, liver, and kidney of Danio rerio.

Titanium dioxide nanoparticles (Np-TiO2) have become the common component of sunscreen cosmetic products. Np-TiO2 can affect especially aquatic ecosystems health, including aquatic organisms such as fish. It is therefore necessary to acquire a better understanding of the effect of Np-TiO2 on aquatic organisms. This study evaluated the biological effects of Np-TiO2 on Danio rerio, such as survival rate and weight change and, in particular, the Ti content or retention in the intestine and liver, as well as the activities of catalase and superoxide dismutase enzymes. In addition, the structure of the intestine, kidney, and liver was investigated through histological analysis. Ninety zebrafish were used, randomly divided into three treatment-groups: a control group (fed with food without adding Np-TiO2) and two groups of fish fed with food containing Np-TiO2 exposed for 7 and 14 days. The amount of Ti in the liver and intestine was measured using atomic absorption spectrophotometry coupled to a graphite furnace (GFAAS). Morphological analysis and enzyme catalase and superoxide dismutase assays were likewise performed. Ti was detected in all fish even in control group; probably Ti must have been introduced during production by the fish food industry. Structural changes were detected in fish fed with Np-TiO2 as vacuolization and disruption of the apical cytoplasm of epithelial cells that covered the intestinal villi. Although kidney morphology appeared intact, the lumen of the proximal tubule was enlarged, and the cells of the distal tubule were vacuolated. No morphological changes in the liver were detected; however, superoxide dismutase activity decreased, suggesting that liver changes occurred at the molecular level. Thus, Np-TiO2 causes morphological changes in the intestine, kidney, and liver of zebrafish and biochemical changes in the liver exposed for 7 and 14 days. Although not highly lethal, Np-TiO2 in the food chain can interfere with the morphophysiology of aquatic organisms. Neither mortalities nor body weight losses were recorded among fish in all groups over the duration of the experiment.

Propolis reversed cigarette smoke-induced emphysema through macrophage alternative activation independent of Nrf2.

Chronic obstructive pulmonary disease (COPD) is an incurable and progressive disease. Emphysema is the principal manifestation of COPD, and the main cause of this condition is cigarette smoke (CS). Natural products have shown antioxidant and anti-inflammatory properties that can prevent acute lung inflammation and emphysema, but there are few reports in the literature regarding therapeutic approaches to emphysema. We hypothesized that supplementation with natural extracts would repair lung damage in emphysema caused by CS exposure. Mice were exposed to 60days of CS and then treated or not with three different natural extracts (mate tea, grape and propolis) orally for additional 60days. Histological analysis revealed significant improvements in lung histoarchitecture, with recovery of alveolar spaces in all groups treated with natural extracts. Propolis was also able to recovery alveolar septa and elastic fibers. Propolis also increased MMP-2 and decreased MMP-12 expression, favoring the process of tissue repair. Additionally, propolis recruited leukocytes, including macrophages, without ROS release. These findings led us to investigate the profile of these macrophages, and we showed that propolis could promote macrophage alternative activation, thus increasing the number of arginase-positive cells and IL-10 levels and favoring an anti-inflammatory microenvironment. We further investigated the participation of Nrf2 in lung repair, but no Nrf2 translocation to the nucleus was observed in lung cells. Proteins and enzymes related to Nrf2 were not altered, other than NQO1, which seemed to be activated by propolis in a Nrf2-independent manner. Finally, propolis downregulated IGF1 expression. In conclusion, propolis promoted lung repair in a mouse emphysema model via macrophage polarization from M1 to M2 in parallel to the downregulation of IGF1 expression in a Nrf2-independent manner.

Histochemical analysis, smooth muscle immunolocalization and volumetric density of the elastic system fibres of the ostrich (Struthio camelus) phallus.

There are few scientific reports on the histology of the phallus of ratite birds. The aim of this study was to conduct a histochemical analysis to determine the distribution of smooth muscle cells and the volumetric density (Vv) of the fibres of the elastic system in the ostrich phallus. Adult ostriches, 14 months old, were used. The phalluses were fixed in Bouin's solution and then transferred to a buffered formalin solution. They were then processed using standard histological stains for paraffin and slices were obtained. The following techniques were performed: HE, Picrosirius red, Alcian Blue at pH 1.0 and 2.5. The Periodic acid-Schiff reagent and Weigert's Resorcin-Fuchsin with previous oxidation were performed. The M42 test system was used to quantify the elastic system fibres. For immunohistochemical analysis, an anti alpha smooth muscle actin monoclonal antibody was used. The surface of the phallus is covered by a non-keratinized stratified squamous epithelium, which becomes stratified cylindrical in the region of the spermatic sulcus. No glands associated with the connective tissue were observed. The Vv of the elastic system fibres was 4.75%. Smooth muscle cells were visualized only in the walls of blood vessels through immunostaining, with an absence in the lymphatic sinuses. Despite similarities with other birds, such as the presence of a fibrous external axis, a lymphatic core, and a spermatic groove, the ostrich phallus shows marked differences, including the absence of an elastic core, a non-keratinized lining epithelium, and the absence of glands throughout its extension.

Nifedipine in semi-solid formulations for topical use in peripheral vascular disease: preparation, characterization, and permeation assay.

Nifedipine (NFD) has been used for the treatment of cutaneous lesions caused by peripheral vascular disease and diabetic ulcers. NFD was formulated at 8% in three semi-solid formulations: Polaxamer 407 Lecithin Organogel (PLO), PLO plus Transcutol(®), and an oil-in-water (o/w) emulsion. In vitro release and permeation tests were carried out using a synthetic (cellulose acetate) or natural membrane (pig ear skin), respectively, mounted in a Franz-type diffusion cell at 37°C in a constant water bath. As a receptor solution, isotonic phosphate buffer at pH 7.4 was used. All samples were analyzed by high-performance liquid chromatography by employing a previously validated method. The drug flow values were 6.126 ± 0.288, 4.030 ± 0.081, and 6.660 ± 0.254 µg/cm(2)/h for PLO, PLO plus Transcutol(®), and o/w emulsion, respectively. The three formulations did not show significant differences in drug flow, considering p > 0.05. Furthermore, their penetration profiles in both the epidermis and dermis were statistically different. Thus, the incorporation of NFD in PLO, PLO plus Transcutol(®), and o/w emulsion changed the drug thermodynamic activity, as expected. In addition, Transcutol(®) increased the solubility of NFD in the formulation and promoted its penetration in both the epidermis and dermis.

Bubble plastic use in rats hernioplasty: Uso do plástico bolha em hernioplastias de ratos.

Purpose: Despite the high frequency of hernioplasties worldwide, their complications and recurrences are still a challenge to be overcome. The search for prostheses that aim to promote the correction of hernia defects has been a challenge. For this purpose, the materials used in hernioplasties must be biocompatible, promote the formation of little or no peritoneal adhesion, possess compatible texture and flexibility, providing the necessary resistance to protect the viscera and allow the movement of the abdomen. Methods: The aim of the present study was to evaluate the effectiveness of bubble plastic (low density polyethylene, LDPE) as a material for the correction of hernia in the abdominal wall. For this, twenty male rats (Rattus norvegicus, Wistar variety) were used and divided into four groups of five animals. The animals were evaluated at 7, 15, 30 and 90 days after surgery according to clinical, thermographic and morphological parameters (macroscopic and microscopic). Results: The results showed that the bubble plastic induced inflammatory reaction in the initial period (7 day), followed by a reduction (30 day) to increase considerably at 90 days after the operation. Conclusion: So, bubble plastic can be used for temporary implants (up to 30 days).

Treatment with Bixin-Loaded Polymeric Nanoparticles Prevents Cigarette Smoke-Induced Acute Lung Inflammation and Oxidative Stress in Mice.

The use of annatto pigments has been evaluated as a therapeutic strategy in animal models of several health disorders. Beneficial effects were generally attributed to the inhibition of oxidative stress. Bixin is the main pigment present in annatto seeds and has emerged as an important scavenger of reactive oxygen (ROS) and nitrogen species (RNS). However, this carotenoid is highly hydrophobic, affecting its therapeutic applicability. Therefore, bixin represents an attractive target for nanotechnology to improve its pharmacokinetic parameters. In this study, we prepared bixin nanoparticles (npBX) and evaluated if they could prevent pulmonary inflammation and oxidative stress induced by cigarette smoke (CS). C57BL/6 mice were exposed to CS and treated daily (by gavage) with different concentrations of npBX (6, 12 and 18%) or blank nanoparticles (npBL, 18%). The negative control group was sham smoked and received 18% npBL. On day 6, the animals were euthanized, and bronchoalveolar lavage fluid (BALF), as well as lungs, were collected for analysis. CS exposure led to an increase in ROS and nitrite production, which was absent in animals treated with npBX. In addition, npBX treatment significantly reduced leukocyte numbers and TNF-α levels in the BALF of CS-exposed mice, and it strongly inhibited CS-induced increases in MDA and PNK in lung homogenates. Interestingly, npBX protective effects against oxidative stress seemed not to act via Nrf2 activation in the CS + npBX 18% group. In conclusion, npBX prevented oxidative stress and acute lung inflammation in a murine model of CS-induced acute lung inflammation.

Pulmonary Fibrosis and Hypereosinophilia in TLR9-/- Mice Infected by Cryptococcus gattii.

Cryptococcus gattii is a worldwide-distributed basidiomycetous yeast that can infect immunocompetent hosts. However, little is known about the mechanisms involved in the disease. The innate immune response is essential to the control of infections by microorganisms. Toll-like receptor 9 (TLR9) is an innate immune receptor, classically described as a non-methylated DNA recognizer and associated with bacteria, protozoa and opportunistic mycosis infection models. Previously, our group showed that TLR9-/- mice were more susceptible to C. gattii after 21 days of infection. However, some questions about the innate immunity involving TLR9 response against C. gattii remain unknown. In order to investigate the systemic cryptococcal infection, we evaluated C57BL/6 mice and C57BL/6 TLR9-/- after intratracheal infection with 104C. gattii yeasts for 21 days. Our data evidenced that TLR9-/- was more susceptible to C. gattii. TLR9-/- mice had hypereosinophilia in pulmonary mixed cellular infiltrate, severe bronchiolitis and vasculitis and type 2 alveolar cell hyperplasia. In addition, TLR9-/- mice developed severe pulmonary fibrosis and areas with strongly birefringent fibers. Together, our results corroborate the hypothesis that TLR9 is important to support the Th1/Th17 response against C. gattii infection in the murine experimental model.

Subacute exposure to lead promotes disruption in the thyroid gland function in male and female rats.

Exposure to heavy metals, such as lead, is a global public health problem. Lead has a long historic relation to several adverse health conditions and was recently classified as an endocrine disruptor. The aim of this study was to investigate the effects of subacute exposure to lead on the thyroid gland function. Adult male and female Wistar rats received a lead acetate solution containing 10 or 25 mg/kg, by gavage, three times a week, for 14 days. One week later, behavioral testing showed no alterations in anxiety and motor-exploratory parameters, as evaluated by Open-Field and Plus-Maze Tests, but impairment in learning and memory was found in the male 25 mg/kg lead-treated group and in both female lead-treated groups, as evaluated by the Inhibitory Avoidance Test. After one week, serum levels of tT3 were reduced in the 25 mg/kg female group and in the 10 mg∕ kg male group. However, tT4 levels were increased in the 25 mg/kg male group and in both female treated groups. TSH levels did not change and lead serum levels were undetectable. Morphologic alterations were observed in the thyroid gland, including abnormal thyroid parenchyma follicles of different sizes, epithelial stratification and vacuolization of follicular cells, decrease in colloid eosinophilia and vascular congestion, accompanied by morphometric alterations. An increase in collagen deposition was also observed. No differences were observed in TPO activity or protein expression, H2O2 generation by NADPH oxidases or hepatic D1 mRNA expression. However, thyroid NIS protein expression was considerably decreased in the male and female lead-treated groups, while TSHr expression was decreased in the 25 mg/kg female lead-treated group. These findings demonstrated that subacute exposure to lead acetate disrupts thyroid gland function in both sexes, leading to morphophysiological impairment and to changes in learning and memory abilities.

The role of Toll-like receptor 9 in a murine model of Cryptococcus gattii infection.

Toll-like receptor 9 (TLR9) is crucial to the host immune response against fungi, such as Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans, but its importance in Cryptococcus gattii infection is unknown. Our study aimed to understand the role of TLR9 during the course of experimental C. gattii infection in vivo, considering that the cryptococcal DNA interaction with the receptor could contribute to host immunity even in an extremely susceptible model. We inoculated C57BL/6 (WT) and TLR9 knock-out (TLR9-/-) mice intratracheally with 104 C. gattii yeast cells. TLR9-/- mice had a higher mortality rate compared to WT mice and more yeast cells that had abnormal size, known as titan cells, in the lungs. TLR9-/- mice also had a greater number of CFUs in the spleen and brain than WT mice, in addition to having lower levels of IFN-γ and IL-17 in the lung. With these markers of aggressive cryptococcosis, we can state that TLR9-/- mice are more susceptible to C. gattii, probably due to a mechanism associated with the decrease of a Th1 and Th17-type immune response that promotes the formation of titan cells in the lungs. Therefore, our results indicate the participation of TLR9 in murine resistance to C. gattii infection.

Localization of hematopoietic cells in the bullfrog (Lithobates catesbeianus).

Amphibians represent the first phylogenetic group to possess hematopoietic bone marrow. However, adult amphibian hematopoiesis has only been described in a few species and with conflicting data. Bone marrow, kidney, spleen, liver, gut, stomach, lung, tegument, and heart were therefore collected from adult Lithobates catesbeianus and investigated by light microscopy and immunohistochemical methods under confocal laser microscopy. Our study demonstrated active hematopoiesis in the bone marrow of vertebrae, femur, and fingers and in the kidney, but no hematopoietic activity inside other organs including the spleen and liver. Blood cells were identified as a heterogeneous cell population constituted by heterophils, basophils, eosinophils, monocytes, erythrocytic cells, lymphocytes, and their precursors. Cellular islets of the thrombocytic lineage occurred near sinusoids of the bone marrow. Antibodies against CD34, CD117, stem cell antigen, erythropoietin receptor, and the receptor for granulocyte colony-stimulating factor identified some cell populations, and some circulating immature cells were seen in the bloodstream. Thus, on the basis of these phylogenetic features, we propose that L. catesbeianus can be used as an important model for hematopoietic studies, since this anuran exhibits hematopoiesis characteristics both of lower vertebrates (renal hematopoiesis) and of higher vertebrates (bone marrow hematopoiesis).

Microscopical methods promote the understanding of the integument biology of Rhinella ornata.

In Rhinella ornata, the integument of different body regions was investigated using low-vacuum scanning electron and light microscopy through histochemical and immunohistochemical methods, and revealed the basic structure found in other anurans. Keratinocytes formed the keratinized squamous stratified epithelium, and flask cells occurred among the epidermal superficial layer. Just below the epidermis, the dermis was subdivided into a spongious dermis and a compact dermis. Mixed and granular glands were located in the spongious dermis, and myoepithelial cells surrounded their secretory portions. The Eberth-Katschenko (EK) layer occurred as basophilic areas between the spongious and compact dermis and throughout the spongious dermis. A series of alternating layers of bundles of collagenous fibers characterized the compact dermis, being firmly attached to a thin hypodermis. Regarding the morphological features, each integument region revealed distinct structural aspects. The dorsal integument was rougher than ventral, having conical tubercles and spines upon the verrucae. In the ventral and subgular regions, the slightly elevations are visualized, tubercles were absent but some spines occurred. The pelvic integument had a non-keratinized epidermis with an irregular profile and small poorly developed elevations. In addition, the EK layer was absent, and the presence of numerous blood vessels suggests its participation in water absorption and distribution. In the parotoid gland, the epidermis was similar to the dorsal integument; except that the reticular dermis was present, and contained three exocrine glandular types. Expression of cytokeratin was evident in the basal and intermediary layer, but absent in the cornified layer. Flask cells showed strong cytokeratin labeling. Consequently, the integument had the basic morphology, but exhibits regional characteristics, which may be related to the physiology of each surface.

Chondroitin sulfate isolated from the secretion of the venom-producing parotoid gland of Brazilian bufonid.

The parotoid gland of bufonids is characterized as a specialized integument region, formed by different gland types. The secretion elaborated by the largest glandular alveoli has been related to animal chemical defense and is constituted by granular protein content, associated with a basophilic and alcianophilic material with features of glycoconjugates. This study aimed to identify and characterize the glycoconjugates in the secretion of the largest granular gland of the parotoid gland of Rinella icterica by histochemical and immunohistochemical techniques at light microscopy, biochemical methods, and nuclear magnetic resonance spectroscopy. Our results showed that the glycoconjugate content contains a mixture of chondroitin­6­sulfate (C6S) and chondroitin-non-sulfate (C0S). Thus, chondroitin sulfate probably plays an important role in gland physiology, probably protecting the protein content while inside the secretory portion.

Structure of the sexually dimorphic gland of Cycloramphus fuliginosus (Amphibia, Anura, Cycloramphidae).

Cycloramphus fuliginosus males (Amphibia, Leptodactylidae) have discoid glandular elevations on the abdominal inferior body region which are considered a characteristic of genus. In this work, this sexually dimorphic gland of C. fuliginosus was investigated by low vacuum scanning electron microscopy, light microscopy, and transmission electron microscopy. In this cycloramphid, the covered integument exhibits the basic structure: the epidermis, a keratinized squamous stratified epithelium with flask cells, and the dermis. The dermis is subdivided into spongious and compact dermal layers. In the iliac gland region, an aggregate of small mucous glands and larger syncytial tubuloalveolar glands occur in the spongious dermis, and they do not go beyond the Eberth-Katschenko layer limit. The adenocytes of the mucous gland produce neutral glycoproteins, in contrast to the larger tubuloalveolar glands that elaborate a proteinaceous secretion. Myoepithelial cells surround the alveoli, and play an important role in the secretion extrusion. The final secretion, elaborated by the iliac gland, is a mixture of mucus and protein. Both secretions are important to the cycloramphid biology, and may act as pheromone and/or as chemical parental care.

Hyaluronan in the epidermal and the dermal extracellular matrix: its role in cutaneous hydric balance and integrity of anuran integument.

New researches have revealed that hyaluronan (HA) is not a passive molecule. HA has being pointed out to participate in many processes, such as cell interactions, proliferating and migrating cell events and function as hydrate agent. The present study was undertaken to localize HA in Bufo ictericus integument providing a better understating for the role of cutaneous HA. Paraffinized sections were stained with haematoxylin-eosin and with 1% Alcian blue 8GX at pH 1.0 and 2.5. Alcianophilic reaction was visualized in both spongious dermis and Eberth-Katschenko layer. The mucus cells of mucus glands were also stained with AB methods. Besides these histological techniques, the localization of HA was performed using the FITC-labeled HA probe labeled with fluorescein isothiocyanate. In the extracellular matrix of spongious dermis, the reaction for HA was evident, being less intense in hypodermis and in pericellular keratinocyte matrix of the cornified tubercles regions. Thus, since HA was localized in the pericellular epidermal matrix and in the spongious dermis of anuran integument, it plays an important role in hydric balance, and is essential for integument integrity and functionality.

Expression pattern of glycoconjugates in the integument of Bufo ictericus (Anuran, Bufonidae): biochemical and histochemical (lectin) profiles.

Mucous consists of glycoproteins and proteoglycans produced by specific secretory cells (mucocytes). In anurans the cutaneous mucous is produced by intradermal glands and displays both mechanical and chemical protection functions. Indeed, mucous maintains the integument moist and facilitates gas exchange (cutaneous respiration). In this work, the carbohydrate moiety distribution was investigated in the integument of Bufo ictericus using conventional and lectin histochemistry to describe the pattern of cutaneous glycoconjugate expression, including both secretory and structural proteoglycans. As a preliminary step, the descendent chromatography in Whatmann 1MM paper was undertaken to prepare the histochemical trials involving the lectins. In B. ictericus, the integument exhibits the basic morphological structure found in lower terrestrial vertebrates: the epidermis is a keratinized squamous stratified epithelium supported by spongious and compact layers. The spongy dermis contain secretory portion of both mucous and serous (or poison) glands. The paper chromatography identified galactose, fucose and mannose as characteristic sugar residues. The secretory cells of the mucous gland in the dermis, as well as the interstice between the stratum corneum and the subjacent stratum spinosum in the epidermis exhibit alpha-l-fucose and alpha-galactose residues. The serous glands give no reaction. The alpha-mannose residue was detected in the extracellular matrix of spongious dermis, but not in the dermal glands. The different glycoconjugate location reflects in two glycoconjugates categories: the secretory which participate in the water flow regulation, and the structural which is involved in the dermal maintenance.

Influence of feeding habits in the endocrine pancreas of insectivore bat Pteronotus personatus and nectarivore bat Anoura geoffroyi: A comparative stereological and immunohistochemical study.

Pteronotus personatus as an insectivore bat and has a diet that consists of a high protein diet, whereas the diet of Anoura geoffroyi, a predominantly nectarivore bat, is rich in simple sugars like sucrose, glucose and fructose. Considering that diet influences the activation of different pathways, which may influence morphological adaptations in the gastrointestinal system, the aim of this study was to compare the morphology of the endocrine pancreas in P. personatus and A. geoffroyi. For this, histological, stereological and immunohistochemical methods were used. In P. personatus, the average diameter of the pancreatic islet was 40.47µm±13.94, while in A. geoffroyi was 88.16µm±36.40. The total number of pancreatic islets in P. personatus was 26150±2346 and in A. geoffroyi was 15970±1666. In P. personatus, the volume density of the pancreatic islets was 3.4%± 2.6, whereas in A. geoffroyi the volume density was 6.1%±3.7. In addition, the immunodensity of the α, ß and δ cells, in P. personatus was 25.8%±11.9, 35.5%±13.5, 3.9%±0.7, respectively, and in A. geoffroyi was 33.10%±12.7, 55.08%±7.4, 6.2%±4.6, respectively. In conclusion, the results of this study indicate differences in the pancreatic weight/body, weight ratio, diameter and volume density of pancreatic islets and in immunodensity of the ß and α cells between both species, which have different dietary habits.

Dermal collagen organization in Bufo ictericus and in Rana catesbeiana integument (Anuran, Amphibian) under the evaluation of laser confocal microscopy.

Collagen structural organization plays an important role in the mechanical property of the vertebrate integument. Bufo ictericus and Rana catesbeiana integument was investigated by light microscopy and laser confocal microscopy. Collagenous elements of the dermis were statistical analyzed. The integument is formed by the keratinized squamous stratified epidermis supported by the dermis that is subdivided into the spongious layer with a loose arrangement, and the compact layer formed by collagenous fibers arranged compactly in a criss-crossed manner. Thick collagenous columns have a perpendicular trajectory, and are formed by the assembling of alternating collagenous lamellae in both animals. Short intercolumns of collagenous fibrils connecting collagenous lamellae obliquely or transversally are observed in R. catesbeiana dorsal integument. The present study provides evidences that B. ictericus and R. catesbeiana integument has well-organized compact dermis, constituted by collagenous lamellae in a plywood manner. The integument organization is in contrast to the literature in some aspects. This dermal arrangement is important to the biomechanical property of both anuran integuments.