Fig 1 - uploaded by Zhichao Dang
Content may be subject to copyright.
Effects of cortisol on plasma osmolality (A), sodium levels (B), and plasma cortisol levels (C) in tilapia at day 5 following dietary cortisol administration at low (125 mg kg −1 ), middle (375 mg kg −1 ) and high (750 mg kg −1 ) doses; carrier-treated food served as a control (CTRL). Values are means ± S.E.M. (N=10). Asterisks indicate significant differences from control values: *P<0.05, **P<0.01.
Source publication
The effect of cortisol on Na(+)/K(+)-ATPase expression in the gill chloride cells of tilapia Oreochromis mossambicus was studied by immunocytochemistry at the light and electron microscope levels. One of three doses of cortisol (low, 125 mg kg(-1 )food; middle, 375 mg kg(-1 )food; high, 750 mg kg(-1) food) was administered via the food (at a ration...
Contexts in source publication
Context 1
... plasma osmolality and Na + levels were found in the middle-and high-cortisol groups when compared to controls, as shown in Fig. 1A,B. Plasma cortisol levels were only elevated in the high-dose group as compared to controls (Fig. 1C). Cortisol treatments did not alter blood hematocrit values (mean value for pooled data: 27.6±0.8 %; (range: 26.3-34.8; N=40) nor plasma glucose levels (results not ...
Context 2
... plasma osmolality and Na + levels were found in the middle-and high-cortisol groups when compared to controls, as shown in Fig. 1A,B. Plasma cortisol levels were only elevated in the high-dose group as compared to controls (Fig. 1C). Cortisol treatments did not alter blood hematocrit values (mean value for pooled data: 27.6±0.8 %; (range: 26.3-34.8; N=40) nor plasma glucose levels (results not ...
Citations
... Cortisol is an indicator of stress that plays a key role in the stress response in animals by shuttling energy away from growth to other metabolic processes, including gluconeogenesis (Das et al., 2018;Pankhurst, 2011). The activity of NKA in the plasma membrane of gills cells increases following increases in the concentration of cortisol (Dang et al., 2000). Mohamed et al. (2021) showed that increases in the concentration of cortisol in tilapia following long-term salinity treatment resulted in increases in the activity of NKA. ...
... Na + /K + -ATPase Na + /K + -ATPase (NKA), a highly conserved membrane enzyme, is associated with both ion uptake and salt secretion by the gill of teleost fish (Dang et al. 2000;Evans et al. 2005). It is important not merely for sustaining intracellular homeostasis but also providing driving force for many transporting processes (Sarma et al. 2013). ...
The present work aims to evaluate the tolerance, osmoregulation, metabolism, and antioxidant ability of saline water immersed grass goldfish (Carassius auratus) during the recovery in freshwater. Grass goldfish (38.15 ± 5.48g) acclimated in freshwater were immersed by salinities (0‰, 20‰ and 30‰) for different time durations (10, 20, 30 and 60 min); and the physiological responses were measured during freshwater recovery. The blood osmolalities were not significantly different at any group fish, while whereas the decline of Na⁺ concentration and the ratio of Na⁺/Cl⁻ as well as the rise of Cl⁻ concentration was observed in saline treated fish. Soon after freshwater recovery, the transcription of NKA-α and NKA-β mRNA in gills of salinity 20 immersed fish elevated significantly and then decreased, whereas no obvious changes were detected in salinity 30 treated fish. Till 24h post freshwater recovery, gill Na+/K+-ATPase activities in saline treated fish were lower than control group except for the fish immersed by salinity 20 for 10–30 min. At 24h of recovery, cortisol levels in salinity 20 immersed fish were lower than salinity 30 treated fish, but remained higher than control. As for serum lactic acid, fish treated by salinity 20 for 10 or 20 min did not show any fluctuation. However, higher lactic acid contents were detected in all other five salinity treated groups during recovery. Generally, at 24 h of recovery, salinity 20 treated fish exhibited higher SOD and CAT activities than fish immersed by salinity 30. In summary, grass goldfish could survive by immersion in salinity 20 less than 60 min or salinity 30 less than 30min, even though immersion by salinity 20 could minimize the negative effects.
... Na + /K + -ATPase (NKA), a highly conserved membrane enzyme, is associated with both ion uptake and salt secretion by the gill of teleost sh (Dang et al. 2000;Evans et al. 2005). It is important not merely for sustaining intracellular homeostasis but also providing driving force for many transporting processes. ...
The present work aims to evaluate the tolerance, osmoregulation, metabolism, and antioxidant ability of saline water immersed grass goldfish ( Carassius auratus ) during the recovery in freshwater. Grass goldfish (38.15 ±5.48g) acclimated in freshwater were immersed by two salinities (20 ‰ or 30 ‰) for different time durations (10min, 20min, 30min, and 60min); and the physiological stress responses were measured during a recovery period of 24 h. Resultly, osmotic pressure kept unchanged in all treated fish, whereas the decline of sodium ions, potassium ions, and the ratio of Na ⁺ /Cl ⁻ was observed in saline treated fish. Differently, concentrations of chloride ion in saline treated fish were higher than control fish, but decreased as recovery time went. Soon after freshwater recovery, the gill Na ⁺ /K ⁺ —ATPase in saline treated fish kept lower than control group except for the fish immersed by salinity 20 for 10 – 30 min. Specifically, gill Na ⁺ /K ⁺ —ATPase levels showed a decreased trend in all saline treated fish, but the mRNA of NKA-α and NKA-β both significantly increased at 1h and 6h in salinity 20 treated fish.Compared with control group, cortisol levels were increased in all salinity 20 treated fish at 1h of recovery, but then gradually declined. However, in salinity 30 treated group, cortisol levels showed a rise trend and maintained high levels until 24 h post recovery. As for serum lactic acid, fish treated by salinity 20 for 10 or 20 min did not show any fluctuation. Whereas there was a rise trend of lactic acid in fish immersed by salinity 20 for 30 min and 60 min as recovery time went on. Fish treated by salinity 30 exhibited a relative high level of serum lactic acid at 1h and then gradually decreased at 24 post recovery. What’s more, antioxidant capacities were higher at salinity 20 treated fish than salinity 30 immersed fish. The limited results indicated that grass goldfish could well osmoregulate and survive by immersion in salinity 20 less than 60 min or salinity 30 less than 30min, even though immersion by salinity 20 could minimize the negative effect.
... After salinity challenge, plasma cortisol elevated at 30 min PSC in all groups, which may be attributed to its osmoregulatory function under seawater acclimation (McCormick, 2001). As the main seawater-adapting hormone, cortisol prompts ion uptake rate through increasing gill Na + -K + ATPase enzyme activity and size and number of chlorides cells (Foskett et al., 1983;McCormick, 1995;Dang et al., 2000;Wong and Chan, 2001;Khoshnood et al., 2010;Nemova et al., 2021). However, cortisol concentrations were higher at 30 PSC in NiCl 2 exposed fish than in non-exposed ones, confirming stress-inducing role of NiCl 2 . ...
The gray mullet, Mugil cephalus is an inshore and bottom-feeding fish species of Oman sea. Therefore, the gray mullet may be more exposed to heavy metal contamination, as the toxic impacts of heavy metals mullet has been reported in various studies. This study was conducted to evaluate the toxic effects of the heavy metal, nickel (as NiCl2) on osmoregulation of the gray mullet by measuring blood biochemicals, hormones, minerals and gill histology. Fish (10 fish/tank) were experimentally exposed to NiCl2 at three environmentally relevant concentrations of 5, 10 and 15 μg/l for 96 h. Then, fish were challenged with seawater (35 mg/l) for a period of 120 min. The samples (blood and gill tissue) were collected After 96 exposure to NiCl2 and during salinity challenge (30, 60 and 120 min post challenge). The plasma levels of cortisol and glucose significantly increased in NiCl2−exposed fish. In addition, cortisol increased in all experimental groups 30 min after salinity challenge and then returned gradually to the same levels as the control at 120 min post salinity challenge (PSC). The triiodothyronine (T3) and thyroxine (T4) levels significantly decreased in response to 10 and 15 μg/ml NiCl2. In all groups, the thyroid hormones significantly elevated at 30 min PSC. After 30 min PSC, T3 levels in all NiCl2−exposed fish and T4 in the treatment, 10 μg/ml NiCl2 remained unchanged throughout the salinity challenge. In the treatment, 5 μg/ml NiCl2, T4 levels were recovered at 120 min PSC and reached the same levels as the control. Exposure of fish to high concentrations of NiCl2 and salinity stress increased the lactate levels. However, lactate levels in 5 and 10 μg/ml NiCl2 groups were recovered at 120 min PSC and reached the same levels as the control. Furthermore, plasma protein increased in response to 10 and 15 μg/ml NiCl2. At 30 PSC, the protein levels decreased in control and 5 μg/ml NiCl2 group, while it remained unchanged in fish exposed to 10 and 15 μg/ml NiCl2 throughout the salinity challenge. Exposure of fish to NiCl2 disrupted the electrolyte (Na+, Cl−) balance both before and after salinity challenge, which may be due to gill lesions induced by the heavy metal and following alternations in gill permeability. However, fish in 5 μg/ml NiCl2 re-established the ionic balance in the blood at the end of salinity challenge period. The malondialdehyde (MDA) levels significantly increased in response to 10 and 15 μg/ml NiCl2. The MDA levels returned to the same levels as the control group at 120 min PSC. The results of the present study showed that nickel-induced toxicity (especially at high concentrations) can reduce the osmoregulation capabilities of mullet. However, fish are able to recover from the toxic effects over time, if contamination be eliminated.
... The corticosteroid hormone, cortisol, is a known regulator of osmoregulatory function in teleost fishes (e.g. in those migrating from freshwater to seawater [10]). Cortisol has been shown to increase not only the number of gill ionocytes, but also Na + -K + -ATPase (NKA) levels within each cell [2,11]. In the amphibious mudskipper (Periopthalmus modestus), plasma cortisol increased after 1 day of air exposure [12]; however, no links to terrestrial osmoregulation were made. ...
Cortisol is a major osmoregulatory hormone in fishes. Cortisol acts upon the gills, the primary site of ionoregulation, through modifications to specialized ion-transporting cells called ionocytes. We tested the hypothesis that cortisol also acts as a major regulator of skin ionocyte remodelling in the amphibious mangrove rivulus ( Kryptolebias marmoratus ) when gill function ceases during the water-to-land transition. When out of water, K. marmoratus demonstrated a robust cortisol response, which was linked with the remodelling of skin ionocytes to increase cell cross-sectional area and Na ⁺ -K ⁺ -ATPase (NKA) content, but not when cortisol synthesis was chemically inhibited by metyrapone. Additionally, we discovered a novel morphology of skin-specific ionocyte that are spikey with multiple cell processes. Spikey ionocytes increased in density, cell cross-sectional area and NKA content during air exposure, but not in metyrapone-treated fish. Our findings demonstrate that skin ionocyte remodelling during the water-to-land transition in amphibious fish is regulated by cortisol, the same hormone that regulates gill ionocyte remodelling in salinity-challenged teleosts, suggesting conserved hormonal function across diverse environmental disturbances and organs in fishes.
... The reason for this is unknown, but may be related to a proliferation of mitochondria-rich cells (MRCs), as was reported in rainbow trout after daily cortisol injections of 4 ng g − 1 fish for 10 days by Laurent and Perry (1990). Likewise, various cortisol treatments caused increased Na + /K + -ATPase and H + -ATPase activity in the gills of different fish species, conceivably leading to elevated oxygen requirement of this tissue (Dang et al., 2000;Kiilerich et al., 2007;Lin and Randall, 1993;Madsen, 1990;Sunny and Oommen, 2001). Increased oxygen consumption rates were also observed in the livers of cortisol-treated fish in our study. ...
Chronic elevation of circulating cortisol is known to have deleterious effects on fish, but information about the consequences of prolonged cortisol elevation on the metabolism of fish is scarce. To test the effects of chronic cortisol elevation on the aerobic performance of rainbow trout, we examined how two severities of chronically elevated plasma cortisol levels affected the oxygen uptake during rest and after exhaustive exercise using a high (HC) and a medium cortisol (MC) treatment. High cortisol doses significantly affected standard (SMR) and maximum metabolic rates (MMR) compared to control fish. In comparison, the medium cortisol treatment elevated MMR but did not significantly influence SMR compared to a sham group (S) and control group (C). The medium cortisol treatment resulted in a significantly increased metabolic scope due to an elevation of MMR, an effect that was abolished in the HC group due to co-occuring elevations in SMR. The elevated SMR of the HC-treated fish could be explained by increased in vitro oxygen uptake rates (MO 2) of specific tissues, indicating that the raised basal metabolism was caused, in part, by an increase in oxygen demand of specific tissues. Haematological results indicated an increased reliance on anaerobic metabolic pathways in cortisol-treated fish under resting conditions.
... A subsequent study by the same authors showed that even 15 min of exposure to a fluoxetine concentration of 1µg/L reduced cortisol levels in the specimens, confirming a blocking effect on the neuroendocrine stress axis of zebrafish [136]. One of the mechanisms by which cortisol interferes with osmoregulation processes is in the stimulation of the gill Na + /K + ATPase [137]. By measuring ion flux levels in fish, the authors demonstrated that the drug reduced the influx of Na + and K + and, therefore, the cortisol levels blocking the osmoregulatory effects triggered by stress. ...
To date, drug pollution in aquatic systems is an urgent issue, and Danio rerio is a model organism to study the toxicological effects of environmental pollutants. The scientific literature has analyzed the effect of human drug pollution on the biochemical responses in the tissues of D. rerio adults. However, the information is still scarce and conflicting, making it difficult to understand its real impact. The scientific studies are not consistent with each other and, until now, no one has grouped their results to create a baseline of knowledge of the possible impacts. In this review, the analysis of literature data highlights that the effects of drugs on adult zebrafishes depend on various factors, such as the tissue analyzed, the drug concentration and the sex of the individuals. Furthermore, the most influenced biochemical responses concern enzymes (e.g., antioxidants and hydrolase enzymes) and total protein and hormonal levels. Pinpointing the situation to date would improve the understanding of the chronic effects of human drug pollution, helping both to reduce it in the aquatic systems and then to draw up regulations to control this type of pollution.
... Hence, cortisol can be used mostly as an efficient indicator during stressful conditions [98,99]. Cortisol also causes the increase in Na + -K + -ATPase in the plasma membrane of the gill cells [100]. While increase in cortisol and plasma ion concentration may act in concert to promote salinity acclimation, they have distinct and specific effects, eg: the induction of osmotic stress transcription factor 1 (OSTF1) by the increased osmolality but not cortisol [101,102]. ...
Salinity has a stronger individual effect on organismal performance traits than other stressors, hence it is considered as a potent environmental stressor. Salinity acclimation process forces fish to undergo endocrinological, morphological and biochemical changes This paper would serve to provide a better understanding about the role of salinity in regulating the survival, growth, development, fitness and well-being of freshwater fish. Certain physiological mechanisms of salinity effects which are yet to be understood fully are also mentioned in the paper. The paper reveals that the 'salinity effect' could not be subject to generalizations as several factors like genetic make-up, species, strain, life history, nutritional status, size, acclimation time and environmental factors affect the salinity tolerance of fish. The paper gives an insight into the research gaps in the area.
... This excretion is attributed to urea transport protein (tUT), which is regulated by the hormone cortisol and the 5-HT neurotransmitter [70]. On the one hand, cortisol stimulates Na+/ K+-ATPase activity in gills [71], stimulating Na + , Cl − and Ca 2+ absorption [72] and increasing the cell chloride area in the gills resulting in the inhibition of ammonia excretion [73,74]. On the other hand, high concentrations of 5-HT stimulate ammonia excretion [75,76]. ...
Fluoxetine is an emerging pollutant that acts as a selective serotonin reuptake inhibitor (SSRI) and being a hydrolytic molecule that is photolytically stable and accumulaties in biological tissues, its disposal in the aquatic environment can interfere with the physiology of fish and shrimp. Thus, the objective of this study was to analyze the effects of fluoxetine on routine metabolism (metabolic rate, specific ammonia excretion and O:N ratio) of Deuterodon iguape and Palaemon pandaliformis. For this, five groups of each species, were exposed to different concentrations of fluoxetine for 24 hours (D. iguape) and 2 hours (P. pandaliformis). The results demonstrated that in D. iguape exposure to fluoxetine significantly increased both the metabolic rate by 75%, 85%, 55% and 50% for concentrations of 0.05; 0.1; 0.5 and 1.0 mgL-1 , respectively, and the specific ammonia excretion by 40%, 48% and 20% for concentrations of 0.05; 0.1 and 0.5 mgL-1 , respectively, when compared with their control. The O:N ratio was statistically greater in concentrations of 0.5 and 1.0 mgL-1. Concerning P. pandaliformis, exposure to fluoxetine increased metabolic rate at concentrations 30.0 and HIGHLIGHTS Fluoxetine increases the metabolic rate and excretion of ammonia in both species. O:N ratio in fish showed higher values in the highest concentrations of fluoxetine. The LC50-96 hour values of Palaemon pandaliformis represented greater toxicity. Both species are a good biological model for fluoxetine exposure studies. 2 Rezende, K.F.O.; et al. Brazilian Archives of Biology and Technology. Vol.64: e21200262, 2021 www.scielo.br/babt 60.0 µgL-1 , and also increased specific ammonia excretion at concentrations 10.0, 30.0 and 60.0 µgL-1 , when compared with the control group. It was concluded that exposure to fluoxetine increases the routine metabolism of both species and that at the concentration 1.0 mgL-1 , Deuterodon iguape required different energy substrates.
... Cortisol can be used mostly as an efficient indicator during stressful conditions (Barton, 2002;Pankhurst, 2011). Cortisol can increase the Na + -K + -ATPase in the plasma membrane of the gill cells (Dang et al., 2000). Also, cortisol levels can regulate the plasma ionic contents, oxidative and immune responses (McCormick, 2011). ...
Nile tilapia (Oreochromis niloticus) is a well-known economic fish species and can grow well under optimum environmental conditions. However, stressful rearing conditions are expected to deteriorate the performance and health condition of fish. Hence, the present study investigated the physiological and ion changes of Nile tilapia under salinity stress. Fish of 200 ± 20 g were divided into three groups where the control group reared in water with 0 ppt salinity, while the second and third groups were raised in water with low salinity (10 ppt) and high salinity (15 ppt), respectively. Blood dissolved oxygen and gases (pH, PO2, PCO2, TCO2, and HCO3⁻) significantly differed in different groups after 5 and 10 days (P < 0.05). The salinity stress affected the Hb, PCV, Na⁺, K⁺, Ca⁺⁺, and lactate significantly (P < 0.05). Serum cortisol, triiodothyronine, and free triiodothyronine concentrations after 5 and 10 days were significantly affected (P < 0.05) in salinity stressed groups compared to the control group. Serum malondialdehyde showed a significant increase (P < 0.05) after 5 days in the stressed groups, then became non-significant after 10 days compared to the control group. The relative gene expression of Na⁺-K⁺-ATPase and cytosolic carbonic anhydrase were significantly upregulated in salinity stressed groups (P < 0.05). The histopathological images of Nile tilapia exposed to high salinity stress revealed damage in gills, liver, and kidney tissues, which confirmed the harmful effects of increased salinity. Thus, the obtained results demonstrated that the adverse effects of high salinity stress on the health status of Nile tilapia.
