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In aquaculture, ozone is used as a disinfectant. In its production, extensive amounts of oxygen are formed resulting in hyperoxic conditions in culture units. Both ozone and hyperoxia have the potential to be toxic via pro‐oxidant mechanisms and to activate antioxidant defence systems in cultured species. To eliminate systemic effects, blood of rainbow trout, Oncorhynchus mykiss (Walbaum), was exposed in vitro for 5 min to ozone/hyperoxia or hyperoxia, and changes in antioxidant defences and lipid peroxidation were measured after exposure. Ozone exposure caused severe damage in red blood cells (rbc) detected as increased lipid peroxidation and oxidized glutathione (GSSG) levels in both plasma and rbc. Oxygen exposure alone increased intracellular lipid peroxidation and GSSG levels 10 min after exposure and was not evident in the plasma at any time. Ozone, but not oxygen exposure, decreased reduced glutathione (GSH) levels in plasma, and the changes were negatively correlated with increased lipid peroxidation in rbc, indicating that extracellular GSH has a dynamic role in the protection of rbc from direct oxidation by ozone. Both ozone and hyperoxic conditions increased superoxide dismutase (SOD) activity in rbc 3 and 6 h after exposure. In contrast, catalase activity was only increased 10 min after oxygen exposure, suggesting other catalase activation mechanisms rather than enzyme induction. The recovery of lipid peroxidation and GSSG levels in rbc after hyperoxia, but not ozone exposure, indicated a capacity to defend against hyperoxia‐produced oxidative damage, but an overwhelming of antioxidant defences by ozone in rainbow trout rbc in vitro. 相似文献
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ObjectiveTo determine the effects of propofol or thiopental induction on intraocular pressures (IOP) in normal dogs.Study designProspective randomized experimental study.AnimalsTwenty-two random-source dogs weighing 19.5 ± 5.3 kg.MethodsDogs were randomly assigned to receive propofol 8 mg kg−1 IV (group P) or thiopental 18 mg kg−1 IV (group T) until loss of jaw tone. Direct arterial blood pressure, arterial blood gasses, and IOP were measured at baseline, after pre-oxygenation but before induction, before endotracheal intubation, and after intubation.ResultsThere were no significant differences between groups with regard to weight, body condition score, breed group, or baseline or before-induction IOP, arterial blood pressure, or blood gases. The baseline IOP was 12.9 mmHg. Before endotracheal intubation, IOP was significantly higher compared to baseline and before induction in dogs receiving propofol. After intubation with propofol, IOP was significantly higher compared to thiopental and was significantly higher compared to before induction. After intubation, IOP was significantly lower compared to before intubation in dogs receiving thiopental. Propofol increased IOP before intubation by 26% over the before-induction score and thiopental increased IOP by 6% at the same interval. The IOP in group P remained 24% over the before induction score whereas thiopental ultimately decreased IOP 9% below baseline after intubation. There was no significant relationship between any cardiovascular or blood gas parameter and IOP at any time. There was no significant relationship between the changes in any cardiovascular or blood gas parameter and the changes in IOP between time points.Conclusions and clinical relevancePropofol caused a significant increase in IOP compared to baseline and thiopental. Thiopental caused an insignificant increase in IOP which decreased after intubation. Propofol should be avoided when possible in induction of anesthesia in animals where a moderate increase in IOP could be harmful. 相似文献
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Abstract Temperature and oxygen gradients exist in nearly every water body, but anthropogenic activities can subject fish to rapid changes in these important environmental variables. These rapid changes in temperature and oxygen (generally referred to as temperature or oxygen shock) may have sub‐lethal consequences depending upon the magnitude and the fish species. This study quantified physiological changes in largemouth bass, Micropterus salmoides (Lacepède), exposed to two levels of heat and cold shocks and to two levels of hypoxic and hyperoxic shocks. Following a cold shock from 20 °C to 8 °C, plasma cortisol and glucose increased after 1 h and lactate dehydrogenase activity increased after 6 h. Plasma glucose and K+ concentrations increased 1 h after a heat shock from 20 °C to 32 °C but not after 6 h. Bass subjected to a hypoxic shock from 8 to 2 mg O2 L?1 showed decreased plasma K+ and increased plasma glucose and white muscle lactate. No changes in physiological parameters were observed in bass subjected up to 18 mg O2 L?1 hyperoxia. Results from this study suggest that largemouth bass can tolerate a wide range of temperature and oxygen shocks, but temperature decreases of 20 to 8 °C and hypoxia as low as 4 mg O2 L?1 should be avoided to minimise physiological perturbations. 相似文献
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N.C. Wendling D.C. Bencic J.J. Nagler J.G. Cloud R.L. Ingermann 《Fish physiology and biochemistry》2000,22(3):217-223
To further examine the concept of egg quality and the physiology of stored salmonid eggs, we investigated the effects of different oxygen tensions on the adenosine triphosphate (ATP) levels of unfertilized, activated, and fertilized chinook salmon (Oncorhynchus tshawytscha) eggs. The ATP levels of unfertilized chinook salmon eggs were 2.61±0.14 nmol ATP per egg (17.6±0.9 mol l–1 relative to cell water) and ranged from 1.98 to 3.63 nmol ATP per egg. The ATP content of unfertilized eggs maintained at 10 °C under 100% O2, 21% O2, and 100% N2 remained unaltered throughout a 120 h storage period. Storing eggs under identical conditions at 20 °C (in an effort to speed egg metabolism and ATP turnover) resulted in significant O2-independent decreases in ATP levels. However, ATP levels of unfertilized eggs exposed to 1 mmol l–1 potassium cyanide (a potent inhibitor of oxidative phosphorylation) at 10 °C were significantly decreased after 24 h and continued to decline throughout the 120 h maintenance period to about 30% of time=0 values. Maintenance with exogenous nutrients (5 mmol l–1 acetate plus 5 mmol l–1 pyruvate) over 120 h at 10 °C did not alter the ATP content of unfertilized eggs. Eggs activated by exposing them to 10 °C water for a few minutes showed a rapid decrease in ATP values, regardless of whether the eggs were fertilized or not. Following an initial 25% drop after fertilization, the ATP levels remained stable for the remainder (5 d) of the incubation period in eggs maintained in 10 °C water. Therefore, unfertilized chinook salmon egg ATP levels appear to be relatively stable and maintained by a low, cyanide-inhibitable metabolism. The stability of egg ATP levels may be one reason that salmonid eggs can be stored for several days while eggs from other fishes cannot. 相似文献
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【目的】比较高浓度氧处理法(高氧法)与传统HCl处理法(HCl法)阻断蚕卵滞育效果的差异,探讨高氧法阻断滞育在家蚕Bombyx mori转基因技术体系上的应用。【方法】采用高氧法和HCl法在产后20 h处理二化性蚕品种‘大造’,比较孵化率、孵化时间,调查高氧法的最佳处理条件;将高氧法应用于一化性蚕品种‘土耳其’和转基因二化性蚕品种‘大造’,调查其对一化性蚕品种蚕卵阻断滞育效果及转基因二化性蚕品种显微注射后蚕卵阻断滞育效果。【结果】高氧法对二化性蚕卵在孵化率、孵化时间上都与HCl法有相近的阻断滞育的效果,其最佳条件为产卵后20 h用体积分数为70%的O2处理40 h;该方法也能成功阻断一化性蚕品种,孵化率达(71±20)%;高氧法处理的显微注射转基因家蚕卵孵化率达到了(49±9)%,而对照组的孵化率为0。【结论】高氧法为今后生产上替代HCl法,采用安全环保的蚕卵阻断滞育技术,解决转基因蚕卵阻断滞育和提高转基因家蚕育种进度的关键问题提供了可行的新方法。 相似文献
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Physiological and morphological effects of severe hypoxia,hypoxia and hyperoxia in juvenile turbot (Scophthalmus maximus L.) 
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下载免费PDF全文 We studied the physiological status of juvenile turbot (Scophthalmus maximus L.) under severe hypoxia (1 and 2 mg/L dissolved oxygen, DO), hypoxia (3 and 5 mg/L DO), hyperoxia (11 and 14 mg/L DO) and normoxia (7 mg/L DO, control) conditions. The respiratory rates, haematology parameters, acid–base balance status and gill structure were analysed to find the effects of different DO concentration on turbot. Fish mortality was only observed under severe hypoxia conditions. Severe hypoxia caused an increase in respiratory rates and red blood cell counts, as well as an increase in haemoglobin and haematocrit levels in the fish. In fish exposed to hypoxia conditions, the respiratory rate increased overall as the DO concentration decreased. Lower pCO2 and HCO3? levels led to a high blood pH, while the pO2 remained stable. In hyperoxia groups, respiratory rate decreased as the DO concentration increased. The levels of pCO2 and HCO3? significantly increased (P < 0.05), while the pO2 level and blood pH did not change obviously. The gill structure was damaged after prolonged exposure to hyperoxia, but no obvious damage was found in hypoxia groups. The fish that survived the hypoxia or hyperoxia treatment were able to restore the structural integrity of the gills after 14 days' recovery. The results suggest that juvenile turbots can tolerate a wide range of DO concentrations. However, even mild hyperoxia condition (11 mg/L DO), which is widely used in fish culture, has adverse effects on juvenile turbot physiology. 相似文献
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D.C. Bencic M. Krisfalusi J.G. Cloud R.L. Ingermann 《Fish physiology and biochemistry》1999,21(3):193-200
Adenosine triphosphate (ATP) levels in sperm from steelhead trout (Oncorhynchus mykiss) were found to be 12.0 ± 1.4 pmol ATP per 106 sperm cells. Sperm were stored at 0–2 °C for up to 72 h under 100 and 21% O2, and 100% N2. The sperm ATP content of samples maintained under 100 and 21% O2 both decreased to about 70 and 50% of initial values after 24 and 72 h, respectively. ATP levels of sperm stored under 100% N2 decreased to 20% of initial values after only 4 h and to less than 10% of initial values after 24 h; they remained unchanged throughout the following 48 h. These low levels, however, were reversible. Following 4 h incubation under 100% N2, sperm ATP levels rose upon exposure to and maintenance under 100% O2, increasing to 50% of initial values after a total of 72 h. ATP levels in sperm maintained with cyanide for 4 h decreased to less than 5% of initial values. The magnitude of the change in sperm ATP levels after 24 h in samples maintained under 100% O2 correlated positively with the initial sperm ATP levels. Sperm ATP levels, motility, and fertility were all correlated positively in a subset of samples examined. The initial percent of living sperm (sperm viability) was 97.5 ± 0.5% and was unaltered through 24 h under all O2 tensions. Sperm viability remained unchanged through 72 h under 21% O2 and decreased by 10 and 30% by 72 h under 100% O2 and 100% N2, respectively. Therefore, reductions in sperm ATP levels could not be attributed to cell death as viability decreased only modestly over these durations. Spermatocrit values were unaltered throughout the 72 h incubation for samples maintained under 100 and 21% O2, however, a 95% increase in spermatocrit occurred after 72 h in samples maintained under 100% N2. These data indicate that intracellular ATP in steelhead trout sperm can be modulated by ambient oxygen without significant loss of viability and that this ATP has a probable role in cell motility and fertility, and sperm packing and cell flexibility. 相似文献
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The effect of water oxygen saturation on growth and haematological profile of juvenile peled Coregonus peled (Gmelin) 下载免费PDF全文
下载免费PDF全文 Jan Matousek Marketa Prokesova Katsiaryna Novikava Roman Sebesta Eliska Zuskova Vlastimil Stejskal 《Aquaculture Research》2017,48(10):5411-5417
The effect of varying oxygen saturation regimes on growth and haematological profiles of peled Coregonus peled was investigated on fish of initial age 90 days post hatching. Eighty‐five juveniles per group (initial body weight 3.09 ± 0.80 g) were submitted to a 63‐day experiment with one of four water saturation regimes: normoxia (NORm, 80%–90%), hypoxia (HYPo, 50%–60%), hyperoxia (HYPe, 150%–160%) and intermittent hyperoxia (iHYPe, 150%–160% ‐ 80%–90%). Survival rate in NORm, HYPe and iHYPe ranged from 96.3 ± 2.1% to 97.7 ± 2.7, but survival 87.5 ± 3.0 was significantly lower in the HYPo group. No differences were observed in feed conversion ratio. The highest final body weight of 18.2 ± 4.6 g and a specific growth rate of 2.81 ± 0.01%/day were seen in the NORm group. Significant differences were found in haemoglobin concentration with increased saturation. The fish had lower haemoglobin 55.00 ± 5.72 and 51.35 ± 10.89 g/L in treatments HYPe, iHYPe with compared to the normoxia (64.22 ± 5.78 g/L). Haematocrit was similar in the groups HYPo, NORm and iHYPe (0.55 ± 0.04, 0.58 ± 0.05 and 0.54 ± 0.09) with the exception of HYPe, which was significantly lower (0.48 ± 0.06). Significantly lower count of erythrocyte was observed in iHYPe group (0.88 ± 0.20) with compared to the normoxia (1.06 ± 0.13). The supersaturation level was not associated with effects on growth and survival, and adding oxygen is not recommended for intensive rearing of peled. The results showed normoxia oxygen level to be the most suitable conditions for peled. 相似文献
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