scholarly journals Cortisol regulates epithelial permeability and sodium losses in zebrafish exposed to acidic water

2013 ◽  
Vol 217 (3) ◽  
pp. 253-264 ◽  
Author(s):  
Raymond W M Kwong ◽  
Steve F Perry
Keyword(s):  
Paracellular Permeability ◽  
Acid Exposure ◽  
Whole Body ◽  
Control Fish ◽  
Epithelial Permeability ◽  
Negative Consequences ◽  
Acidic Water ◽  
Peg 4000 ◽  
Water Ph ◽  
Body Absorption

The effects of cortisol on epithelial permeability and sodium (Na+) handling during acid exposure were investigated in larval zebrafish (Danio rerio). The results demonstrated that the whole-body absorption of the paracellular permeability marker polyethylene glycol-4000 (PEG-4000) decreased with increasing levels of exogenous cortisol. Western blot analysis revealed that the abundance of the epithelial tight junction proteins occludin-a and claudin-b was increased after cortisol treatment. Furthermore, translational gene knockdown of claudin-b using an antisense morpholino oligonucleotide caused an increase in the permeability to PEG-4000, which was mitigated by cortisol treatment, further suggesting a role for cortisol in reducing paracellular permeability. Exposure to acidic water (pH 4.0 vs 7.6) caused an expected increase in the diffusive loss of Na+and a decrease in whole-body Na+levels. These disruptive effects of acute acid exposure on Na+balance were reduced by treatment of larvae with exogenous cortisol. Translational knockdown of the glucocorticoid receptor (GR) abolished the effects of cortisol on epithelial PEG permeability, suggesting that activation of GR was probably the major signaling pathway for reducing epithelial permeability. During acid exposure, the epithelial PEG permeability in the GR morphants was significantly higher than in the control fish. Additionally, GR morphants exhibited a more pronounced diffusive loss of Na+than the control fish during acid exposure. These findings suggest that cortisol may help to minimize the negative consequences of acid exposure on Na+homoeostasis via GR-mediated reductions in epithelial permeability and paracellular Na+loss.

scholarly journals A role for sodium-chloride cotransporters in the rapid regulation of ion uptake following acute environmental acidosis: new insights from the zebrafish model

2016 ◽  
Vol 311 (6) ◽  
pp. C931-C941 ◽  
Author(s):  
Raymond W. M. Kwong ◽  
Steve F. Perry
Keyword(s):  
Acid Exposure ◽  
Whole Body ◽  
Cell Type ◽  
Acidic Water ◽  
Zebrafish Model ◽  
Larval Zebrafish ◽  
Water Ph ◽  
Control Water ◽  
Compensatory Regulation

The effects of acute exposure to acidic water on Na+ and Cl− homeostasis, and the mechanisms underlying their compensatory regulation, were investigated in the larval zebrafish Danio rerio. Exposure to acidic water (pH 4.0; control pH 7.6) for 2 h significantly reduced Na+ uptake and whole body Na+ content. Nevertheless, the capacity for Na+ uptake was substantially increased in fish preexposed to acidic water but measured in control water. Based on the accumulation of the Na+-selective dye, Sodium Green, two ionocyte subtypes exhibited intracellular Na+ enrichment after preexposure to acidic water: H+-ATPase rich (HR) cells, which coexpress the Na+/H+ exchanger isoform 3b (NHE3b), and a non-HR cell population. In fish experiencing Na+-Cl− cotransporter (NCC) knockdown, we observed no Sodium Green accumulation in the latter cell type, suggesting the non-HR cells were NCC cells. Elimination of NHE3b-expressing HR cells did not prevent the increased Na+ uptake following acid exposure. On the other hand, the increased Na+ uptake was abolished when the acidic water was enriched with Na+ and Cl−, but not with Na+ only, indicating that the elevated Na+ uptake after acid exposure was associated with the compensatory regulation of Cl−. Further examinations demonstrated that acute acid exposure also reduced whole body Cl− levels and increased the capacity for Cl− uptake. Moreover, knockdown of NCC prevented the increased uptake of both Na+ and Cl− after exposure to acidic water. Together, the results of the present study revealed a novel role of NCC in the compensatory regulation of Na+ and Cl− uptake following acute acidosis.

Reduction in oocyte production and gonadotrope activity, and plasma levels of estrogens and vitellogenin, in brook trout exposed to low environmental pH

1990 ◽  
Vol 68 (12) ◽  
pp. 2468-2476 ◽  
Author(s):  
W. H. Tam ◽  
J. N. Fryer ◽  
B. Valentine ◽  
R. J. J. Roy
Keyword(s):  
Plasma Levels ◽  
Brook Trout ◽  
Acid Stress ◽  
Secretory Activity ◽  
Experimental Period ◽  
Acid Exposure ◽  
Control Fish ◽  
Cortisol Secretion ◽  
Control Value ◽  
The Mean

Maturing brook trout were exposed to pH 4.5 at the beginning of the rapid oocyte development phase in mid-June. The number of atretic follicles containing vitellogenic oocytes in acid-treated trout gradually increased with time, to exceed that of control fish on day 30, reaching a maximum (22–24% of all vitellogenic oocytes) between days 45 and 60 of acid exposure, before declining on day 73. Follicular atresia reduced the number of healthy vitellogenic oocytes in the acid-stressed fish to 59% of controls by day 60. Plasma vitellogenin and estrogen levels were not consistently affected by acid exposure. During the first 45 days of acid exposure, the mean weight of the healthy vitellogenic oocytes and the plasma levels of estrogen in the acid-exposed fish were at times significantly higher than those of control trout, but after day 45 these differences were no longer observed. Ultrastructural morphometry showed that secretory activity of the gonadotropes in the female acid-stressed brook trout was suppressed. Throughout the experimental period, the acid-exposed trout showed various symptoms characteristic of acid stress, such as elevated ACTH and cortisol secretion, hyperglycemia, acidosis, and hyponatremia. Food intake was reduced to 14% of the control value. These results suggest that the disruptive physiological changes and (or) reduced nutritional status associated with acid stress are responsible for the reduction in activity of the gonadotropes and oocyte atresia.

scholarly journals Association Between Physical Exercise and Mental Health During the COVID-19 Outbreak in China: A Nationwide Cross-Sectional Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Yingjun Nie ◽  
Yuanyan Ma ◽  
Yankong Wu ◽  
Jiahui Li ◽  
Ting Liu ◽  
...  
Keyword(s):  
Mental Health ◽  
Physical Exercise ◽  
Exercise Intervention ◽  
Mitigation Strategies ◽  
Psychological Status ◽  
Whole Body ◽  
Moderate Intensity ◽  
Negative Consequences ◽  
Physical And Mental Health ◽  
Health Burden

The COVID-19 has undergone several mutations, and caused deleterious effects on physical and mental health of people worldwide. Whilst physical exercise is known for its positive effect on enhancing immunity and reducing the negative consequences of unhealthy emotional states caused by the pandemic; there is a severe lack of psychological exercise intervention measures and mitigation strategies to advance the knowledge and role of physical exercise to improve mental health in most countries. This study surveyed the association between physical exercise and mental health burden during the COVID-19 outbreak in China to better understand the influence of different physical exercise types on reducing mental health burden during the pandemic. ANOVA, binary logistic regression, the chi-square test, and Spearman's correlation analysis were used for statistical analysis. 14,715 participants were included. The results showed that Chinese residents had several poor mental health conditions during the COVID-19 outbreak. And there was a significant positive correlation between the extent of adverse effects on mental health and provincial proportions of confirmed COVID-19 cases (r = 0.365, p < 0.05). Some main factors caused an unhealthy psychological status, including epidemic severity (62.77%, 95% CI 58.62-65.64%), prolonged home quarantine (60.84%, 95% CI 58.15-63.25%), spread of large amounts of negative information about COVID-19 in the media (50.78%, 95% CI 47.46-53.15%), limitations in daily life and social interaction (45.93%, 95%CI 42.46-47.55%), concerns about students' learning (43.13%, 95% CI 40.26-45.48%), and worries about being infected (41.13%, 95% CI 39.16-45.23%). There was a significant association between physical exercise and mental health. The largest associations were seen for home-based group entertainment exercise (i.e., family games, rope skipping, and badminton), Chinese traditional sports (i.e., Chinese martial arts, Taijiquan and Qigong), and popular sports (i.e., yoga, video dancing, sensory-motor games, and whole-body vibration), as well as durations of 30-60 min per session, frequencies of three to five times per week and a total of 120-270 min of moderate-intensity exercise weekly during the COVID-19 outbreak (p < 0.05).

Effects of Diet or Liming on Steroid Hormone Metabolism and Reproduction in Atlantic Salmon (Salmo salar) Held in an Acidic River

1990 ◽  
Vol 47 (12) ◽  
pp. 2422-2430 ◽  
Author(s):  
G. B. Sangalang ◽  
H. C. Freeman ◽  
J. F. Uthe ◽  
L. S. Sperry
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Reproductive Performance ◽  
Steroid Hormone ◽  
Control Fish ◽  
Dietary Salt ◽  
Hormone Metabolism ◽  
Atlantic Salmon Salmo Salar ◽  
Water Ph ◽  
Acidic River

Attempts to avert the impacts of an acidic river environment on Atlantic salmon (Salmo salar) were carried out in 1985 and 1986. Salmon were held in the Westfield River (pH 4.7–5.2) and the nearby Medway River (pH 5.3–5.6) during their sexual maturation. A diet containing 3% NaCl was fed to the Westfield salmon in 1985. Marble chips were used to elevate the pH of Westfield River water in 1986. Fish fed the salt diet had higher peak levels of plasma sex hormones, higher fecundity, greater incidence of spawners, lower egg mortality, and less weight loss than fish fed a commercial trout diet. The reproductive performance of fish held in limed water (pH 5.1–5.9) almost attained the level observed in the Medway (control) fish. Limestone treatment stimulated early peaking of blood androgen levels, testosterone, and 11-ketotestosterone in Westfield males, and 17α, 20β-dihydroxy-4-pregnen-3-one, a follicular mediator of gonadotropin, in a few Westfield females. The head kidneys produced more cortisol and corticosterone in all Westfield fish in both years compared to Medway fish. The results suggest that neither dietary salt nor liming completely prevented the decline of reproductive performance and the alteration of steroid hormone metabolism in salmon.

Absorption of trace metals in the zinc-deficient rat

1975 ◽  
Vol 228 (4) ◽  
pp. 1020-1023 ◽  
Author(s):  
CJ Hahn ◽  
GW Evans
Keyword(s):  
Molecular Weight ◽  
Trace Elements ◽  
Gel Filtration ◽  
Weight Fraction ◽  
Intestinal Content ◽  
Whole Body ◽  
Low Molecular Weight ◽  
Zinc Absorption ◽  
Body Absorption ◽  
Insight Into

The effects of zinc deficiency on the whole-body absorption and intestinal content of Zn, Cd, Cu, Co, Fe, Mn, and Cr were determined in the rat 1 h after oral administration of the isotopes. Both the absorption and intestinal content of Zn and Cr were increased in zinc-deficient rats, and the intestinal content of Feand Co was also increased in the zinc-deficient animals. Zinc administered orally with Cr decreased both absorption and intestinal content of the isotope in zinc-deficient rats. Chromium administered orally with Zn decreased intestinal content and absorption of Zn in zinc-deficient rats. Fractionation of mucosal supernatants by gel filtration showed that both zinc and chromium eluted in the same low molecular weight fraction. The elution patterns of zinc and cadmium from that of zinc-supplemented animals. These experiments provide some insight into the specificity of the zinc absorption pathway and present some explanations for the interaction or lack of interaction among trace elements.

Elastic ankle exoskeletons reduce soleus muscle force but not work in human hopping

2013 ◽  
Vol 115 (5) ◽  
pp. 579-585 ◽  
Author(s):  
Dominic James Farris ◽  
Benjamin D. Robertson ◽  
Gregory S. Sawicki
Keyword(s):  
Inverse Dynamics ◽  
Average Rate ◽  
Plantar Flexion ◽  
Metabolic Cost ◽  
Whole Body ◽  
Negative Consequences ◽  
Metabolic Power ◽  
Force Peak ◽  
Inverse Dynamics Analysis

Inspired by elastic energy storage and return in tendons of human leg muscle-tendon units (MTU), exoskeletons often place a spring in parallel with an MTU to assist the MTU. However, this might perturb the normally efficient MTU mechanics and actually increase active muscle mechanical work. This study tested the effects of elastic parallel assistance on MTU mechanics. Participants hopped with and without spring-loaded ankle exoskeletons that assisted plantar flexion. An inverse dynamics analysis, combined with in vivo ultrasound imaging of soleus fascicles and surface electromyography, was used to determine muscle-tendon mechanics and activations. Whole body net metabolic power was obtained from indirect calorimetry. When hopping with spring-loaded exoskeletons, soleus activation was reduced (30–70%) and so was the magnitude of soleus force (peak force reduced by 30%) and the average rate of soleus force generation (by 50%). Although forces were lower, average positive fascicle power remained unchanged, owing to increased fascicle excursion (+4–5 mm). Net metabolic power was reduced with exoskeleton assistance (19%). These findings highlighted that parallel assistance to a muscle with appreciable series elasticity may have some negative consequences, and that the metabolic cost associated with generating force may be more pronounced than the cost of doing work for these muscles.

scholarly journals Partially Defatted Hermetia illucens Larva Meal in Diet of Eurasian Perch (Perca fluviatilis) Juveniles

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1876
Author(s):  
Vlastimil Stejskal ◽  
Hung Quang Tran ◽  
Marketa Prokesova ◽  
Tatyana Gebauer ◽  
Pham Thai Giang ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Proximate Composition ◽  
Hematological Parameters ◽  
Fatty Acid Content ◽  
Perca Fluviatilis ◽  
Whole Body ◽  
Control Fish ◽  
Final Body Weight ◽  
Hermetia Illucens ◽  
Perch Perca Fluviatilis

Insect meal is gaining increased attention in aquafeed formulations due to high protein content and an essential amino acid profile similar to that of fishmeal. To investigate insect meal in feed for European perch Perca fluviatilis, a promising candidate for European intensive culture, we replaced standard fishmeal with partially defatted black soldier fly Hermetia illucens larva meal at rates of 0%, 20%, 40% and 60% (groups CON, H20, H40 and H60, respectively) and compared growth performance, somatic indices, hematological parameters, whole-body proximate composition and occurrence of spleen lipidosis. In addition, we assessed the economic and environmental sustainability of the tested feeds by calculating economic conversion ratio (ECR) and economic profit index (EPI). The tested groups did not differ in survival rate. Significant differences were documented in final body weight and specific growth rate, with the highest values in CON, H20 and H40. The proximate composition of fish whole-body at the end of the experiment did not differ in dry matter, crude protein or ether extract, while organic matter, ash and gross energy composition showed significant differences. The fatty acid content and n-3/n-6 ratio showed a decreasing trend with increasing H. illucens larva meal inclusion. No differences were found in hematological parameters among tested groups. The H. illucens larva meal inclusion significantly affected ECR and EPI, even at 20% inclusion level the cost of diets did not differ from the control fish meal based diet. Results suggested that 40% inclusion of H. illucens larva meal can be used successfully in standard diets for perch.

Effects of Aluminum on the Leopard Frog, Rana pipiens: Life Stag Comparisons and Aluminum Uptake

1990 ◽  
Vol 47 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Joseph Freda ◽  
D. Gordon McDonald
Keyword(s):  
Rana Pipiens ◽  
Low Ph ◽  
The Body ◽  
Leopard Frog ◽  
Whole Body ◽  
Toxicity Tests ◽  
Al Content ◽  
Wide Range ◽  
Water Ph ◽  
Percent Mortality

In this study, we conducted a series of toxicity tests investigating the response of embryos, prestage 25 tadpoles and 3-wk old tadpoles of the leopard frog (Rana pipiens) to a wide range pf pH (4.2–4.8) and Al (0–1000 μg∙:L−1}, and to pH 6.5 with no Al present. In embryos and prestage 25 tadpoles, Al ameliorated the toxic effects of very low pH's (4.2–4.4), while becoming toxic at higher pH's (4.6–4.8). Although both embryos and prestage 25 tadpoles were killed by low pH (pH 4.2–4.4 and 4.2, respectively) and elevated Al ([Formula: see text] and [Formula: see text] Al, respectively), embryos were relatively more sensitive (i.e. higher percent mortality) to low pH, whereas prestage 25 tadpoles were relatively more sensitive to Al Three week old tadpoles did not die at any test pH (without Al) and mortality (>20%) caused by Al occurred at only pH 4.8 and 750–1000 μg∙L−1 Al. The body sodium concentrations of 3-wk old tadpoles that survived high Al exposure were depressed indicating sublethal stress. Whole body Al uptake in 3-wk old tadpoles was also elevated in water containing high concentrations of Al, but it was positively related to water pH and exposure time. This result suggests that body Al content is not an accurate indicator of Al exposure in tadpoles living in acidic, Al contaminated ponds.

scholarly journals Peningkatan pH air asam dengan kompos daun ubi kasesa (Manihot sp.) untuk kegiatan akuakultur

2021 ◽  
Vol 10 (1) ◽  
pp. 113-128
Author(s):  
Hani Sintiya ◽  
Eva Prasetiyono ◽  
Endang Bidayani
Keyword(s):  
Experimental Method ◽  
Raw Material ◽  
Acidic Water ◽  
Initial Ph ◽  
Water Ph

ABSTRAKUbi kasesa yang banyak terdapat di Pulau Bangka memiliki daun yang dapat dimanfaatkan sebagai bahan baku pembuatan kompos untuk meningkatkan pH air dalam akuakultur. Penelitian bertujuan untuk menganalisis efektivitas dan menentukan dosis terbaik kompos daun ubi kasesa terhadap kenaikan pH air akuakultur. Metode eksperimental menggunakan Rancangan Acak Lengkap (RAL) tunggal dengan 4 perlakuan dan 3 ulangan. Dosis kompos daun ubi kasesa yang digunakan adalah 0 g/L (P0), 1,25 g/L (P1), 2,25 g/L (P2), 3,25 g/L (P3). Hasil uji statistik menunjukkan adanya pengaruh nyata penggunaan kompos daun ubi kasesa terhadap kenaikan pH air. Nilai pH air awal sebesar 3,6 meningkat masing-masing 5,83±0,06, 7,07±0,06, 7,23±0,12, 7,37±0,06 pada P0, P1, P2, dan P3 setelah diberikan kompos daun ubi kasesa. Air yang diberi kompos tersebut selanjutnya digunakan untuk pemeliharaan ikan nila. Hasil penelitian menunjukkan bahwa dosis kompos daun ubi kasesa terbaik adalah P3 dengan dosis kompos sebesar 3,25 g/L. Kata kunci: akuakultur;  kompos; pH air; ubi kasesa  ABSTRACTMany kasesa tuber is grown in Bangka where the leaves can be used as raw material for making compost to increase pH in aquaculture. This study aims to analyze the effectiveness and determine the best dose of “kasesa” leaves compost to increase the pH for aquaculture activities.This study used an experimental method with a Single Randomized Complete Design (CRD). The treatments consisted of 4 treatments and 3 replications. The doses compost were 0 g/L (P0), 1,25 g/L (P1), 2,25 g/l (P2), 3,25 g/L (P3). The results showed that composting was effective in raising the pH of acidic water. The initial pH of water is 3.6. After being given kasesa leaves compost, the result of pH water for P0, P1, P2, and P3 were 5,83±0,06; 7,07±0,06; 7,23±0,12; 7,37±0,06; respectively. This study showed that the best level of “kasesa” leaves compost was 3.25 g/L. Keywords: aquaculture; compost; kasesa tuber; water pH

scholarly journals Downstream pH Changes in Water Flowing Over the Gills of Rainbow Trout

1986 ◽  
Vol 126 (1) ◽  
pp. 499-512 ◽  
Author(s):  
PATRICIA WRIGHT ◽  
TOM HEMING ◽  
DAVID RANDALL
Keyword(s):  
Rainbow Trout ◽  
Carbonic Anhydrase ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Stopped Flow ◽  
Water Acidification ◽  
Interlamellar Water ◽  
Water Ph ◽  
Ph Stat ◽  
Control Water

We investigated the pH of interlamellar water of trout (Salmo gairdneri) by following changes in the downstream pH of expired water using a stopped-flow method. As water flowed over the gills of control fish, there was a significant decrease in water pH. Acetazolamide added to the water increased the CO2 disequilibrium, while carbonic anhydrase (CA) eliminated the CO2 disequilibrium relative to control water. Mucus excreted by the fish was found to contain CA activity by the pH-stat technique. We conclude water acidification is due to the conversion of excreted CO2 to HCO3− and H+ at the gill surface.

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