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Rolf Erik Olsen Kristina Sundell Einar Ring Reidar Myklebust Gro-Ingunn Hemre Tom Hansen
rjan Karlsen 《Aquaculture (Amsterdam, Netherlands)》2008,280(1-4):232-241
The aim of the present study was to evaluate the effect of stress and nutritional state (fed vs food deprived) on the generalized stress response and intestinal integrity in Atlantic cod (Gadus morhua L.). Cod in feeding or food deprived states were subjected to 15 min of acute stress (exhaustive exercise). Blood was collected at 9 intervals from before stress (t = 0), to t = 48 h post stress and analysed for blood haematocrit and haemoglobin, and plasma cortisol, lactate, glucose, osmolality, chloride, as well as the tissue damage indicators glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and thiobarbituric acid reactive substances. Intestinal segments were prepared for histology with the same intervals, while assessment of intestinal integrity and microbiology was performed at t = 0, 4 and 48 h post stress.Subjecting cod to exhaustive stress initiated a standard stress response including increased blood Hct and plasma cortisol, glucose, chloride, osmolality and lactate. Food deprived fish did in general have reduced stress resistance compared to fed fish. For many parameters, cod returned slowly to basal levels. Cellular indicators of tissue damage and oxidative stress increased in a biphasic manner following stress. Stress did not affect gut histology but did transiently increase gut permeability. Furthermore, stress had no effect on the adherent bacterial population level in midgut, but did cause a small decrease in hindgut (non-significant) and hindgut chamber (p < 0.05). Isolates belonging to Carnobacterium were predominant but not affected by stress.In conclusion, food deprived cod are less resistant to stress than fed cod. The magnitude of the response is less than in salmonids, but the effects are persistent (including tissue damage indicators and oxidative stress) and may have negative long term consequences. The gut is relatively resistant to stress, there is however a transient increase in the intestinal permeability and alterations in microbiota that may indicate lower protection against invading pathogens. 相似文献
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Lixiang Chen Yu-Long Yin Wenjuan S. Jobgen Scott C. Jobgen Darrell A. Knabe Wei-Xin Hu Guoyao Wu 《Livestock Science》2007,109(1-3):19-23
This study was conducted to test the hypothesis that porcine jejunal mucosal cells can degrade all essential amino acids (EAA). Jejunal mucosal cells (primarily enterocytes) were isolated from 50-day-old healthy pigs and incubated at 37 °C for 45 min in Krebs buffer containing plasma concentrations of amino acids and one of the following l-[1-14C]- or l-[U-14C]-amino acids plus unlabeled tracers at 0.5, 2, or 5 mM: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. There was active transamination of leucine, isoleucine and valine in the cells (1.35–2.5 nmol/mg protein per 45 min at 2 mM), with most (67–71%) of their -ketoacids released into the medium. In contrast, catabolism of methionine and phenylalanine was negligible (0.04–0.05 nmol/mg protein per 45 min at 2 mM) and that of other EAA was completely absent in these cells. These results indicate that intestinal mucosal cells are a site for the substantial degradation of branched-chain amino acids but not other EAA in pigs. 相似文献
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CHEN Zhen-yong DAI Hong-mei YANG Peng WANG Yan-gang HUANG Wen-guang FENG Xian-song 《园艺学报》2011,27(11):2194-2198
AIM: To investigate the effects of obstructive jaundice (OJ) on enterocyte chloridion secretion in rats. METHODS: The OJ model of rats was set up. The rats were divided into OJ1 group and OJ2 group randomly. The animals in OJ1 group were sacrificed by exsanguination 7 days after operation and the rats in OJ2 group were sacrificed 14 days after operation. The Cl- concentration in peripheral blood was detected. The epithelial cells in the terminal ileum mucosas were cultured in vitro. The concentration of intracellular Cl- was detected by fluorospectrophotometry. The Cl- current was measured by whole-cell patch clamp experiments. Western blotting was used to examine the change of voltage-gated Cl- channel 2 protein (ClC-2) and the images were analyzed by image analysis system and statistical software quantitatively. RESULTS: The serum Cl- concentration in OJ1 group and OJ2 group were obviously lower than that in control group . The intracellular Cl- relative concentrations in OJ1 group and OJ2 group were higher than that in control group (3.14±0.38 and 3.55±0.47 vs 2.69±0.41,both P<0.05). The Cl- current of normal epithelial cells displayed outward rectification, and transformed negative value into positive value following cell membrane depolarization. The Cl- current was (-15.45±7.56) pA/pF and (5.85±0.81) pA/pF when voltage was -80 mV and 80 mV. The ranges of upgrade of absolute values of average electric current density in OJ groups were lower than those in control group (all P<0.05). Western blotting analysis showed that the ClC-2 protein generated a broad band about 90 kD. The average gradations of Western blotting images were lower in OJ groups than that in control group (0.20±0.04 and 0.19±0.06 vs 0.27±0.06, both P<0.05). However, no difference between the 2 OJ groups was observed (P>0.05). CONCLUSION: The chloridion secretion of intestinal epithelium is restrained in rats with OJ. The concentration gradient between exterior and interior of epithelial cells is decreased, and the Cl- outward current is reduced. All of above are concerned with downregulation of ClC-2 protein in cell membrane. 相似文献
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Jorge Fonseca-Madrigal J. Gordon Bell Douglas R. Tocher 《Fish physiology and biochemistry》2006,32(4):317-328
The objective of this work was to determine whether highly unsaturated fatty acid (HUFA) synthesis and fatty-acid oxidation in Atlantic salmon (Salmo salar L.) intestine was under environmental and/or seasonal regulation. Triplicate groups of salmon were grown through a full two-year cycle on two diets containing either fish oil (FO) or a diet with 75% of the FO replaced by a vegetable oil (VO) blend containing rapeseed, palm, and linseed oils. At key points in the life cycle fatty acyl desaturation/elongation (HUFA synthesis) and oxidation activity were determined in enterocytes and hepatocytes using [1−14C]18:3n−3 as substrate. As observed previously, HUFA synthesis in hepatocytes reached a peak at seawater transfer and declined thereafter, with activity consistently greater in fish fed the VO diet. In fish fed FO, HUFA synthesis in enterocytes in the freshwater stage was at a level similar to that in hepatocytes. HUFA synthesis in enterocytes increased rapidly after seawater transfer, however, and remained high for some months after transfer before decreasing to levels that were again similar to those observed in hepatocytes. Enterocyte synthesis of HUFA was usually higher in fish fed the VO diet than in those fed the FO diet. Oxidation of [1−14C]18:3n−3 in hepatocytes from fish fed FO tended to decrease during the freshwater phase but then increased steeply, peaking just after transfer before decreasing during the remaining seawater phase. At the peak in oxidation activity around seawater transfer, activity was significantly lower in fish fed VO than in fish fed FO. In enterocytes, oxidation of [1−14C]18:3 in fish fed FO reached a peak in activity just before seawater transfer. In fish fed VO, except for high activity at nine months the pattern was similar to that obtained in enterocytes from fish fed FO, with high activity around seawater transfer and declining activity in seawater. In conclusion, fatty acid metabolism in intestinal cells seemed to be under dual nutritional and environmental or seasonal regulation. Temporal patterns of oxidation of fatty acids were usually similar in the two cell types, but HUFA synthesis in enterocytes peaked over the summer seawater phase rather than at transfer, as with hepatocytes, suggesting the possibility of different regulatory cues. 相似文献
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