Snakes are interesting examples of taxa that can overcome energy metabolism challenges, as many species can endure long periods without feeding, and their eventual meals are of reasonably large ...sizes, thus exhibiting dual extreme adaptations. Consequently, metabolic rate increases considerably to attend to the energetic demand of digestion, absorption and protein synthesis. These animals should be adapted to transition from these two opposite states of energy fairly quickly, and therefore we investigated mitochondrial function plasticity in these states. Herein, we compared liver mitochondrial bioenergetics of the boid snake Boa constrictor during fasting and after meal intake. We fasted the snakes for 60 days, and then we fed a subgroup with 30% of their body size and evaluated their maximum postprandial response. We measured liver respiration rates from permeabilized tissue and isolated mitochondria. From isolated mitochondria, we also measured Ca2+ retention capacity and redox status. Mitochondrial respiration rates were maximized after feeding, reaching an approximately 60% increase from fasting levels when energized with complex I-linked substrates. Interestingly, fasting and fed snakes exhibited similar respiratory control ratios and citrate synthase activity. Furthermore, we found no differences in Ca2+ retention capacity, indicating no increase in susceptibility to mitochondrial permeability transition, and no changes in mitochondrial redox state, although fed animals exhibited increases in the release of H2O2. Thus, we conclude that liver mitochondria from B. constrictor snakes increase respiration rates during the postprandial period and quickly improve the bioenergetic capacity without compromising redox balance.
Functional morphology considers form and function to be intrinsically related. To understand organismal functions, a detailed knowledge of morphological and physiological traits is necessary. ...Regarding the respiratory system, the combined knowledge about pulmonary morphology and respiratory physiology is fundamental to understand how animals exchange gases and regulate critical functions to sustain metabolic activity. In the present study, the paucicameral lungs of Iguana iguana were analyzed morphometrically through stereological analysis using light and transmission electron images and compared with unicameral and multicameral lungs of six other non-avian reptiles. The morphological data were combined with physiological information to perform a principal component analysis (PCA) and phylogenetic tests of the relationship of the respiratory system. Iguana iguana, Lacerta viridis, and Salvator merianae presented similar pulmonary morphologies and physiologies when compared to Varanus examthematicus, Gekko gecko, Trachemys scripta, and Crocodylus niloticus. The former species showed an elevated respiratory surface area (%AR), a high diffusion capacity, a low volume of total parenchyma (VP), a low percentage of parenchyma concerning the lung volume (VL), and a higher surface/volume ratio of the parenchyma (SAR/VP), with high respiratory frequency (fR) and consequently total ventilation. The total parenchymal surface area (SA), effective parenchymal surface-to-volume ratio (SAR/VP), respiratory surface area (SAR), and anatomical diffusion factor (ADF) showed a phylogenetic signal, evidence that the morphological traits are more strongly correlated with the species' phylogeny than the physiological traits. In sum, our results indicated that the pulmonary morphology is intrinsically related to physiological traits of the respiratory system. Furthermore, phylogenetic signal tests also indicate that morphological traits are more likely to be evolutionary conserved than physiological traits, suggesting that evolutive physiological adaptations in the respiratory system could happen faster than morphological changes.
•Iguana shows lung morphology similar to reptiles with equivalent metabolic activity.•Integrating morphology and physiology is vital to infer respiratory system evolution.•Lung morphometric traits are more related to species' phylogeny than physiology.
Through the integration of chemical, biochemical and morphological analyses, this study investigated the effects of multiple pollutants on environmental biomarkers, such as gill histopathological ...changes and hematological and biochemical parameters, in Oreochromis niloticus exposed to four sites in the Jacuipe and Subaé rivers over seven days. Sediment analyses identified Sapelba as the most contaminated site, followed by Oliveira de Campinhos, Santo Amaro and Jacuípe. Water analyses revealed aluminum, iron and manganese at all sites. Aluminum and other metal were also detected in the gills of fishes. Fish exposed to the Sapelba site exhibited significant necrosis formation, as well as higher hematological parameters and trend to increase of cortisol levels. However, filament epithelium proliferation was higher at the Oliveira de Campinhos and Santo Amaro sites, at which the lowest levels of the hematological variables were observed. Multivariate analysis grouped some gill histopathological changes together, such as epithelial detachment with edema and lamellar epithelial proliferation with the lamellar fusion of adjacent filaments, revealing relationships among them. Positive associations were identified between sediment contamination and necrosis and cortisol, while water contamination was related with filament epithelium proliferation, aneurism, lamellar fusion and several hematological parameters. Furthermore, relationships between blood parameters and gill histopathological changes demonstrated a joint physiological response that may have resulted from environmental variables such as dissolved oxygen. The results exhibited the direct influence of xenobiotics on these biomarkers but also highlighted the need to consider the complexity of environmental factors to optimize the adoption of these environmental predictive tools.
•Assessment of xenobiotics on the gill tissue and hematological and biochemical parameters.•Gill histopathologies are important biomarkers of aquatic pollution and sediment contamination.•Stereological quantification has great potential in histopathological studies.•Integrated analyzes are fundamental to the understanding of the factors acting on the environment.•More knowledge of methodologies is needed to determine the complexity of environmental factors and employing biomarkers.
Polycyclic aromatic hydrocarbons (PAHs) are petroleum components that, when dissolved in the aquatic environment, can disrupt normal animal physiological functions and negatively affect species ...populations.
Gambusia yucatana
is an endemic fish of the Yucatán Peninsula that seems to be particularly sensitive to the presence of PAHs dissolved in the water. Here, we examined PAH effects on gene expressions linked to endocrine disruption and biotransformation in this species. Specifically, we examined the expression of vitellogenin I (
vtg1
), vitellogenin II (
vtg2
), oestrogen receptor α (
esr1
), oestrogen receptor β (
esr2
), aryl hydrocarbon receptor (
AhR
) and the cytochrome P4503A (
CYP3A
) genes. We exposed
G. yucatana
to different concentrations of PAHs (3.89, 9.27, 19.51 μg/L) over a period of 72 h and found changes associated with reproduction, such as increases in hepatic expression of
vtg
,
esr
,
AhR
and
CYP3A
, mainly at concentrations of 9.27 and 19.51 μg/L. Our results also indicate that benzoapyrene was probably the main PAH responsible for the observed effects. The genes examined here can be used as molecular markers of endocrine-disrupting compounds, as the PAHs, present in the environment, as gene expression increases could be observed as early as after 24 h. These biomarkers can help researchers and conservationists rapidly identify the impacts of oil spills and improve mitigation before the detrimental effects of environmental stressors become irreversible.
Facultative air‐breathing fish can exchange respiratory gases using an air‐breathing organ (ABO), such as the oral cavity of the integument, during environmental hypoxia. The goby Gobionellus ...oceanicus inhabits areas subject to environmental hypoxia; however, its ABO is unknown. To investigate the respiratory potential of G. oceanicus, the gill and integument surface area, diffusion capacity, and their diffusion barrier thickness were measured. Our results show that although gill surface area is smaller than observed in other facultative air‐breathing fish, but it has all features necessary to perform aquatic gas exchange. Additionally the integument of the palate has a short diffusion barrier thickness and a large calculated O2‐diffusion capacity suggesting that it functions as the ABO.
In this figure it is might be observed the relevance of the palate integument for air breathing expressed by the ratio between surface area and body mass (A), surface area and volume (B), anatomical diffusion factor (C) and O2 diffusion capacity (D), when compared to other integument parts.
This study verified the effects of essential oils from
Lippia sidoides
(EOLS) and
Cymbopogon citratus
(EOCC) on the anesthesia of freshwater angelfish (
Pterophyllum scalare
) of two different sizes ...(juveniles I (0.82 g) and II (2.40 g)) and the transport (8 h) of juveniles II. Fish were exposed to different concentrations of EOLS and EOCC: 0, 10, 25, 50, 75, 100, 150, 200, and 250 mg L
−1
. Ventilatory rate (VR) and transport for 8 h with 0, 10, and 15 mg L
−1
of each essential oil were evaluated in juveniles II. The major components found in EOLS and EOCC were carvacrol (44.50%) and α-citral (73.56%), respectively. The best sedation and anesthesia times for both essential oils were obtained with 10 and 25 mg L
−1
and 200 and 250 mg L
−1
for juveniles I and II, respectively. Fish sedated with EOLS had lower VR values than the other treatments. Blood glucose levels were higher in ornamental fish transported with 10 and 15 mg EOLS L
−1
and 15 mg EOCC L
−1
. Hepatic glycogen values were higher in the control group. In general, fish transported with 10 mg EOLS L
−1
showed fewer gill histological alterations than other transported fish. When the type of lesion was evaluated, the highest gill alterations occurred in fish transported with EOCC. In conclusion, 10 mg EOLS L
−1
could be used to transport of juveniles II because although this concentration increased blood glucose levels, it decreased the VR and muscle glycogen levels and caused only mild alterations to the gills.
The aim of this study was to analyze the effect of the acute exposition of polycyclic aromatic hydrocarbons (PAHs) in four different concentrations (4.37, 8.73, 17.46, 34.95 µg L
−1
) in Gambusia ...yucatana, an endemic fish of the Yucatán Peninsula by the characterization of the biomarkers activities: EROD, GST, TBARS, SOD, CAT, and GPx on liver; and AChE on brain. EROD and GST activities increased 292% and 754%, respectively, at the highest concentration (p < 0.0001). TBARS decreased 51%, 49%, and 36% in the three last concentrations (p < 0.0001). SOD activity increased 56% at the highest concentration (p < 0.05). There was no difference in the GPx activity at any treatments. CAT activity decreased 85% at the highest concentration (p < 0.005). AChE activity decreased at all treatments (p < 0.0001). We concluded that PAHs are bioaccumulated and metabolized in G. yucatana mainly at a concentration of 34.95 µg L
−1
; SOD and GPx activities were affected during exposure period compared to the control, indicating the possible mechanism of oxidative stress and AChE could be a good indicator of exposure to PAHs. Finally, we believe that our results could be very useful for the development of G. yucatana conservation strategies.
Enteroaggregative Escherichia coli (EAEC), a biofilm forming pathogen, causes acute and persistent diarrhea worldwide, requiring antimicrobial therapy in severe or persistent cases. To determine the ...susceptibility of EAEC biofilm to antimicrobials, as single-agent or combined therapy, biofilm formation was investigated using EAEC clinical strains via peg lid. Of the 78 initially analyzed strains, 35 could form biofilms, 15 (42.9%; 15/35) were resistant to at least 1 tested antimicrobial and 20 (57.1%) were susceptible to all of them in the planktonic form. The biofilms of these susceptible strains were challenged against chosen antimicrobials, and displayed resistance to tetracycline, trimethoprim-sulfamethoxazole, chloramphenicol, ampicillin, cefotaxime, ceftriaxone (85%–100%), tobramycin (25%), cefoxitin (20%), and ciprofloxacin (5%). Moreover, ciprofloxacin combined with ampicillin, and tobramycin eradicated the biofilm of 2 of the 4 tested strains. Ciprofloxacin, cefoxitin, and tobramycin maintained their activity well against EAEC biofilm, suggesting their possible effectiveness to treat diarrhea caused by biofilm-forming EAEC strains.
The clinical evaluation of enlarged local lymph nodes (LNs) is difficult at the beginning and throughout the follow-up of differentiated thyroid carcinoma (DTC). Although the examination of samples ...collected from LNs by fine-needle aspiration biopsy cytology (FNAB-C) is extremely specific for the diagnosis of metastases, its sensitivity is low, especially in paucicellular samples.
The measurement of thyroglobulin (Tg) in the fine-needle aspiration biopsy (FNAB) washout fluid (FNAB-Tg) increases the diagnostic performance of cytology to up to 100% sensitivity and specificity. However, the application of FNAB-Tg is currently hindered by the absence of methodological standardization, a lack of definite cutoff points, and the ongoing debate regarding its accuracy in nonthyroidectomized patients, those with elevated serum Tg, and those with circulating anti-Tg antibodies.
FNAB-Tg improves the diagnostic performance of FNAB-C in LN metastases, even when the latter is unable to diagnose the metastases. For that reason, FNAB-Tg should be included in the monitoring of DTC.
Gobionellus oceanicus
is a species widely distributed on the Atlantic coast and may be susceptible to anthropic effects. This study evaluated the morphology and the Na
+
/K
+
-ATPase activity of
G. ...oceanicus
gills considering the concentration of metals in the fish and Subaé River estuary. Although the metal concentrations detected in the water and sediment did not exceed certain limits, CONAMA (Brazilian Environment Council), TEL (Threshold Effect Level), and PEL (Probable Effect Level), the metals levels in gills plus muscle and skin of
G. oceanicus
were above the permitted setting of the Ministry of Health, Brazil. The pavement epithelial cells (PVC) of the gill filament was observed that there were long microridges either in the apical surface or in the lamella; especially, microridges degeneration was shown in some PVC from filament epithelium. The number of ionocyte and the volume density were (0.02 ± 0.001)/μm and (0.38 ± 0.27) %, respectively. The activity of Na
+
/K
+
-ATPase was 1.13 ± 0.76 μM Pi mg protein
−1
h
−1
. We describe the volume density and number of ionocytes and Na
+
/K
+
-ATPase enzymatic activity in
G. oceanicus
for the first time, which is useful for basic and comparative future studies to support aquatic biomonitoring.
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