Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Carps”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Survival of F2 transgenic common carp (Cyprinus carpio) containing pRSVrtGH1 complementary DNA when subjected to low dissolved oxygen.

The survival and tolerance of F2 transgenic common carp (Cyprinus carpio) containing pRSVrtGH1 complementary DNA were compared with nontransgenic (control) common carp when subjected to low dissolved oxygen. The tolerance of low oxygen was evaluated in 8 families of common carp in rectangular tanks (3 x 1 x 1 m). The absolute mean percentage of survival of transgenic common carp subjected to low oxygen (0.4 mg/L) was higher (P <0.05) than that of control carp in 2 of the 8 families of common carp tested; however, the overall means for all families of transgenic and control carp were not different (P > 0.05). When oxygen tolerance was measured in time to death rather than absolute survival or mortality, the growth hormone transgenic common carp had a longer group mean (P <0.05) than did controls. The mean survival time in minutes for the transgenic genotype was greater (P <0.05) in 5 of the 8 families assessed. Transgenic common carp in some families had higher percentage and longer times of survival than control common carp when subjected to low oxygen. The definition of tolerance of low oxygen and how it is measured is important, and can affect interpretation of results. The pleiotropic effect of pRSVrtGH1 cDNA on superior survival of low oxygen in common carp has important implications for intensive fish culture.

Journal Article↗

Transforming growth factor-beta/Smads signaling induces transcription of the cell type-restricted ankyrin repeat protein CARP gene through CAGA motif in vascular smooth muscle cells.

Transforming growth factor (TGF)-beta plays a major role in the development of vascular diseases. Despite the pleiotropic effects of TGF-ss on vascular smooth muscle cells (VSMCs), only a few genes have been characterized as direct targets of TGF-beta in VSMCs. Cardiac ankyrin repeat protein (CARP) has been thought to be expressed exclusively in the heart. In the present study, we showed that CARP is expressed in the vasculature after balloon injury and in cultured VSMCs in response to TGF-beta. Analysis of a half-life of the cytoplasmic CARP mRNA levels and the transient transfection of the CARP promoter/luciferase gene indicates that the regulation of CARP expression is increased by TGF-beta at the transcriptional level. Transfection of expression vectors encoding Smads significantly activated the CARP promoter/luciferase activity. Deletion analysis and site-specific mutagenesis of the CARP promoter indicate that TGF-beta response element is localized to CAGA motif at -108 bp relative to the transcription start site. Electrophoretic mobility shift assays showed that the binding activity to the CAGA motif was increased in nuclear extracts of cultured VSMCs by TGF-beta. Cells transfected with adenovirus vector expressing CARP showed a significant decrease in DNA synthesis. Overexpression of CARP enhanced the TGF-beta-mediated inhibition of the DNA synthesis. These data indicate that CARP is a downstream target of TGF-beta/Smad signaling in VSMCs and suggest a role of CARP in mediation of the inhibitory effects of TGF-beta on the proliferation of VSMCs.

3T3 Cells↗

Dietary exposure of mink to carp from Saginaw Bay, Michigan: 2. Hematology and liver pathology.

The effects of consumption of environmental contaminants contained in carp (Cyprinus carpio) from Saginaw Bay, Michigan on various hematological parameters and liver integrity of adult female mink (Mustela vision) were determined. Mink were fed diets that contained 0 (control), 10, 20, or 40% carp prior to and throughout the reproductive period (182 days). The diets contained 0.015, 0.72, 1.53, and 2.56 mg polychlorinated biphenyls (PCBs)/kg diet and 1.0, 19, 40, and 81 pg 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs)/g diet, respectively. Mink fed the diets containing carp showed a general dose-dependent occurrence of clinical signs commonly associated with chlorinated hydrocarbon toxicity, including listlessness, nervousness when approached, anorexia, and melena. Erythrocyte counts were less in mink exposed to Saginaw Bay carp than in controls, while the number of white blood cells was greater than in controls. Significant differences (p < 0.05) in the concentrations of neutrophils, lymphocytes, monocytes, and eosinophils were also found between the control and carp-fed groups, but are considered to be of limited clinical or biological importance. Hematocrit values for the mink fed the 20 and 40% carp diets were significantly less than those of mink in the control and 10% carp groups. There were no significant differences in hemoglobin concentrations among the groups. Necropsies revealed enlarged yellowish livers in many of the carp-fed mink, especially those fed the 40% carp diet. Liver, spleen, and lung weights of carp-fed mink were significantly greater than those of control mink.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Characterization of the carp myosin heavy chain multigene family.

We isolated partial coding sequences for 29 carp myosin heavy chain genes (MyoHCs) and determined the nucleotide sequences around the region encoding the loop 2 of the myosin molecule. The predicted amino acid sequences from the isolated genes all showed very high similarity to those of skeletal and cardiac muscles from higher vertebrates, but not to those of smooth and non-muscle counterparts. Among all clones isolated, carp MyoHC10, MyoHCI-1-3 and MyoHC30 showed exon-nucleotide sequences identical to those of cDNAs encoding the loop 2 region of the 10 degrees C-, intermediate- and 30 degrees C-type fast skeletal isoforms [Hirayama and Watabe, Euro. J. Biochem. 246 (1997) 380-387]. The loop 2 of 28 types of carp MyoHCs was encoded by two exons separated by an intron corresponding to that of the 16th in higher vertebrate MyoHCs, whilst this intron was not found in carp MyoHC30. Although carp MyoHC30 had a gene organization different from those of higher vertebrates and other carp MyoHCs, its predicted amino acid sequence for loop 2 showed the highest homology to those of higher vertebrates among carp MyoHCs. In the 28 carp MyoHCs containing the intron, a combination of different nucleotide sequences for the two resulted in 14 distinct series for the combined coding sequence. These different nucleotide sequences encoded nine distinct amino acid sequences. Phylogenetic analysis for the present loop 2 and light meromyosin previously reported for carp MyoHCs [Imai et al., J. Exp. Biol. 200 (1997) 27-34] revealed that carp MyoHCs have recently diverged and are more closely related to each other than to MyoHCs from other species.

Amino Acid Sequence↗

Ultrastructural changes of the carp (Cyprinus carpio) hepatocyte nucleolus during seasonal acclimatization.

BACKGROUND INFORMATION: The eurythermal fish carp (Cyprinus carpio) adjusts to the seasonal changes in the temperature and photoperiod of its habitat through diverse cellular and molecular mechanisms. We have observed that ribosomal biogenesis is modulated during the acclimatization process and correlates with profound phenotypic changes, reflecting a seasonal-dependent ultrastructural appearance of the nucleolar components. Previous studies using classical techniques showed that in winter-adapted carp the nucleolus appears to be segregated. In the present work, we have reassessed the nucleolar ultrastructural organization of the carp in summer- and winter-adapted fish by using more specific cytochemical and immunocytological techniques. RESULTS: The acetylation method provided evidence that the nucleolar organization is different between winter- and summer-adapted carp. In winter-adapted fish the fibrillar component appears as a unique mass surrounded by several granular caps, whereas in summer-adapted carp the fibrillar component forms few cordons surrounded by granular masses. The nucleolar structure and distribution of the condensed chromatin observed varies upon seasonal acclimatization. In winter the nucleolar chromatin is densely packed in masses that surround the nucleolus, whereas during summer it displays a rather looser organization formed by filaments that not only surround the nucleolus, but also go through the nucleolar body. Using the TdT (terminal deoxynucleotidyl transferase)-immunogold labelling technique, we detected condensed and decondensed nucleolar chromatin, and found some labelling of fibrillar components in both seasons. When liver tissue from summer-adapted carp was treated with AMD (actinomycin D), we observed that the rearrangement of the nucleolar components and condensed chromatin were similar to that found in winter-adapted fish, with differences in the distribution of the perinucleolar chromatin. CONCLUSIONS: The acetylation and TdT-immunogold labelling experiments indicated that the rearrangement of the nucleolar components of winter-adapted carp is very similar to the AMD-treated summer-adapted carp nucleolus, with the latter representing the repression of the ribosomal biogenesis that occurs during the cold season. Nevertheless, the distribution of the condensed perinucleolar chromatin in winter-adapted carp compared with AMD-treated cells suggests that the transcription of rRNA genes in winter-adapted fish is less strongly inhibited and does not lead to the classical segregation of the nucleolus of that described after AMD treatment. In addition, we have confirmed that carp hepatocyte nucleoli comprise only two main structural compartments: a fibrillar component and a granular component. Fibrillar centres were not observed.

Acclimatization↗

Carp hepatopancreatic DNase I: biochemical, molecular, and immunological properties.

A survey of DNase I in nine different carp tissues showed that the hepatopancreas has the highest levels of both DNase I enzyme activity and gene expression. Carp hepatopancreatic DNase I was purified 17,000-fold, with a yield of 29%, to electrophoretic homogeneity using three-step column chromatography. The purified enzyme activity was inhibited completely by 20 mM EDTA and a specific anti-carp DNase I antibody and slightly by G-actin. Histochemical analysis using this antibody revealed the strongest immunoreactivity in the cytoplasm of pancreatic tissue, but not in that of hepatic tissue in the carp hepatopancreas. A 995-bp cDNA encoding carp DNase I was constructed from total RNA from carp hepatopancreas. The mature carp DNase I protein comprises 260 amino acids, the same number as the human enzyme, however, the carp enzyme has an insertion of Ser59 and a deletion of Ala225 in comparison with the human enzyme. These alterations have no influence on the enzyme activity and stability. Three amino acid residues, Tyr65, Val67, and Ala114, of human DNase I are involved in actin binding, whereas those of carp DNase I are shifted to Tyr66, Val68, and Phe115, respectively, by the insertion of Ser59: the decrease in affinity to actin is due to one amino acid substitution, Ala114Phe. The results of our phylogenetic and immunological analyses indicate that carp DNase I is not closely related to the mammalian, avian or amphibian enzymes, and forms a relatively tight piscine cluster with the tilapia enzyme.

Amino Acid Sequence↗

Molecular adaptability of carp myosin: a study of some physico-chemical properties and their comparison with those of rabbit myosin.

During thermal inactivation, the addition of as low as M urea resulted in the reduction of delta G identical to barrier of the inactivation of carp myosin Ca2+-ATPase, whereas that of rabbit myosin remained unaffected. In the absence of urea, a four-hour incubation of carp myosin was accompanied by the release of light chains at 30 degrees C, a value 10 degrees C lower than that for rabbit myosin. Electron micrographs revealed that carp myosin forms artificial thick filaments, which were uniform in size and may differ in a few details from those of rabbit. Not only that helical content of carp myosin was about 4% less than those of rabbit myosin, but it showed more sensitivity to thermal and urea denaturation; and its reversibility upon subsequent cooling or removal of urea was rather poor. The loss in helicity of myosins by urea was a concentration- and temperature-dependent biphasic reaction, with the most obvious effect observed on carp myosin. That carp myosin has increased tendency of unfolding in urea solutions was confirmed by viscosity data and the exposure of thiols also. Even in the absence of urea more SH groups of carp myosin were incorporated by DTNB, and more epsilon-amino groups reacted with NQS. Carp myosin remained in solution till the modification of about 52 surface myosin remained in solution till the modification of about 52 surface amino groups, whereas no precipitation effect was noted in case of rabbit myosin. Neither amino-acid composition nor some parameters derived from it, such as average hydrophobicity polarity index and number of polar side chains, revealed any difference pertinent to the relative stability of the two myosins. On the contrary, the contractile efficiency of carp myosin in the near physiological range was high and thus inversely related with the thermostability. This relationship along with the above evidence has been regarded to demonstrate the adaptability of carp myosin through a loose molecular conformation, which has probably been achieved by the addition of weak interactions in the course of evolution.

Animals↗

[Microsatellite marker analysis of genetic variation between the allotetraploid crucian-carp and their original parents].

Twelve individuals from the allotetraploid crucian-carp,common carp, and red crucian carp were analyzed by using 32 pairs microsatellite primers of the poly (CA) type which were isolated from common carp (Cyprinus carpio L.) by Crooijmans et al. Electrophoretogram patterns showed that 15 pairs of microsatellite primers reproducibly produced the well-identifiable bands. The number of alleles per marker varied from 1 to 8, and the size of alleles ranged from 100 bp to 420 bp. The genetic similarity index between the allotetraploid crucian-carp and their original maternal red crucian carp was 0.5625, and the genetic similarity index between the allotetraploid crucian-carp and their original paternal common carp was 0.5125. The similarity index between red crucian carp and common carp was 0.4204. Both microsatellite and RAPD showed the similar results of the genetic similarity index. However, greater genetic distances were found among microsatellite markers than those among RAPD. These results demonstrate that the microsatellite-based analysis of the genetic variation is useful in measuring intrabiotype differences.

Alleles↗

Distribution of catch-relaxing peptide (CARP)-like immunoreactive neurons in the central and peripheral nervous system of Helix pomatia.

Immunocytochemistry was performed on the nervous system of Helix by the use of an antibody raised against a myotropic neuropeptide, the catch-relaxing peptide (CARP), isolated from Mytilus edulis. In each ganglion of the central nervous system of Helix pomatia, numerous CARP-immunoreactive cell bodies and a dense immunoreactive fiber system could be observed with a dominancy in the cerebral and pedal ganglia. The majority of the immunoreactive neurons are unipolar, although multipolar neurons also occur. In the neuropil areas, CARP-immunoreactive fibers show extensive arborization, which may indicate a central role of CARP. CARP-immunoreactive elements could be observed in each investigated peripheral nerve and peripheral areas, namely in the intestine, heart, aorta, buccal mass, lips, and foot. However, CARP-immunoreactive cell bodies could only be demonstrated in the intestine and the foot musculature. Thin varicose CARP-immunoreactive fibers were observed over both muscle and gland cells in the different peripheral organs, suggesting a peripheral role of CARP. In vivo CARP injection into the body cavity (10(-3), 10(-4), 10(-5) M) altered the general behavioral state of the animals and induced the relaxation of the musculature of the whole body wall indicating that CARP has a significant role in the regulation of muscle contraction.

Amino Acid Sequence↗

Dimerization of the cardiac ankyrin protein CARP: implications for MARP titin-based signaling.

Cardiac ankyrin repeat protein (CARP) and its two close homologs ankrd2 (Arpp) and DARP correspond to a conserved gene family of muscle ankyrin repeat proteins (MARPs). All three genes respond to a variety of stress/strain injury signals with their cytokine-like induction and can associate with the elastic region of titin/connectin. Recently, both CARP and ankrd2 were observed to be elevated in cardiac diseases as well as muscular dystrophies, implicating their joined signaling in muscle diseases. Here we show that CARP in the yeast two-hybrid system (YTH) interacts with itself and desmin. To further verify the YTH data and to investigate possible CARP subunit structure(s), we expressed CARP in E. coli. Expressed CARP has an apparent mobility of about 70 kDa on gel filtration, corresponding to a dimeric species. Yeast two-hybrid experiments using amino- and carboxyterminal deletion clones suggest that CARP, ankrd2, and DARP contain potential coiled-coil dimerization motifs within their unique aminoterminal domains that mediate the formation of homo-dimers. In contrast, we could not detect the formation of hetero-dimers between CARP, ankrd2, and DARP. Therefore, when CARP, ankrd2 and DARP are upregulated in disease/stress states, they are likely to be sorted into distinct structural protein complexes since CARP within the MARP family contains a unique aminoterminal dimerization motif.

Ankyrin Repeat↗

Left-right asymmetric ventricular expression of CARP in the piglet heart: regional response to experimental heart failure.

BACKGROUND AND AIM: Cardiac ankyrin repeat protein (CARP), whose expression is down-regulated in response to doxorubicin (Dox) in vitro, has been proposed to be a marker of experimentally-induced cardiac hypertrophy in rodent models. In piglets, the rapid hypertrophy rate of the left ventricle (LV) as compared to that of the right ventricle (RV) represents a natural model of asymmetric ventricular enlargement. We tested whether CARP expression correlates with postnatal ventricular hypertrophy and to what extent CARP can be sensitive to Dox treatment in vivo. METHODS: CARP mRNA and protein levels were quantified (by Northern blot hybridization, semi-quantitative RT-PCR and Western blot) in the piglet heart, both during early postnatal development and upon Dox-induced cardiomyopathy (Dox-CM). RESULTS: The study revealed: (1) significantly augmented CARP mRNA and protein levels in the LV compared to the RV resulting in left vs. right asymmetry in ventricular CARP expression throughout early postnatal development; (2) dose- and chamber-dependent CARP mRNA and protein enrichment in ventricular myocardium in response to Dox; and (3) abolishment of asymmetric patterns of ventricular CARP expression at heart failure resulting from Dox-CM. CONCLUSIONS: (1) CARP is differentially regulated in the LV and RV during both postnatal development and disease; and (2) monitoring of ventricular CARP expression patterns can be used for further analysis of transition from compensated to overt heart failure.

Animals↗

Putative basal lateral membrane receptors for 24,25-dihydroxyvitamin D(3) in carp and Atlantic cod enterocytes: characterization of binding and effects on intracellular calcium regulation.

The vitamin D metabolite, 24R,25-dihydroxyvitamin D(3) (24R,25(OH)(2)D(3)), was tested for its ability to specifically bind to basal lateral membranes isolated from intestinal epithelium of Atlantic cod (a seawater fish), carp (a freshwater fish), and chicken. Specific saturable binding was demonstrated in membranes from all three species. Membranes from Atlantic cod, carp, and chicken revealed K(d)'s of 7.3 +/- 0.9, 12.5 +/- 0.9 and 7.8 +/- 0.1 nM, and a B(max) for each species estimated to 57.9 +/- 2.9, 195.1 +/- 8.4 and 175 +/- 0.8 fmol/mg protein, respectively. Scatchard analyses indicated a convex curvature and Hill analyses revealed apparent Hill coefficients of 1.84 +/- 0.28, 1.80 +/- 0.29, and 1.78 +/- 0.27 for Atlantic cod, carp and chicken, suggesting a positive cooperative binding in all three species. Basal lateral membranes from Atlantic cod and carp were used to further characterize the binding moiety. In competition studies, basal lateral membranes from Atlantic cod or carp did not discriminate between 24R,25(OH)(2)D(3) and the 24S,25(OH)(2)D(3) isomer, whereas, 1,25(OH)(2)D(3) and 25(OH)D(3), were less effective in competing with [(3)H]24R,25(OH)(2)D(3) for binding to basal lateral membranes in Atlantic cod and carp. In both the Atlantic cod and carp enterocyte basal lateral membranes, the binding activity could be extracted equally well with high salt as with detergent, indicating a peripheral membrane protein rather than an integral membrane binding protein. Finally, isolated Atlantic cod and carp enterocytes were chosen for analyses of signal transduction events mediated by the putative receptor. In both species, 24R,25(OH)(2)D(3) but not 24S,25(OH)(2)D(3), suppressed Ca(2+)-uptake by enterocytes in a dose-dependent manner. Enterocytes from Atlantic cod and carp, acclimated to Ca(2+)-free media, responded by an intracellular Ca(2+)-release within seconds after addition of 24R,25(OH)(2)D(3) or 24S,25(OH)(2)D(3). The effects on intracellular Ca(2+)-release were dose-dependent for both metabolites. 24S,25(OH)(2)D(3) was effective at lower concentrations and triggered a higher response compared to 24R,25(OH)(2)D(3). These results suggest that the binding molecule(s) for 24R,25(OH)(2)D(3) and 24S,25(OH)(2)D(3) is/are capable of acting as a receptor, mediating rapid, non-genomic responses in intestinal cells.

24,25-Dihydroxyvitamin D 3↗

Acyl-CoA: cholesterol acyltransferase and 3-hydroxy-3-methylglutaryl-CoA reductase in carp-liver microsomes: effect of cold acclimation on enzyme activities and on hepatic and plasma lipid composition.

Hepatic microsomal activities of acyl-CoA:cholesterol acyltransferase (ACAT) and 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, rate-limiting enzymes in cholesterol esterification and cholesterol synthesis, and the concentration sand compartmentalization of esterified and unesterified cholesterol, were studied in carp acclimated to 10 and 30 degrees C. Irrespective of acclimation temperature, carp-liver ACAT is characterized by an apparent Km-value for oleoyl-CoA of 11-15 microM and displays an optimum activity at pH 7.4. The enzyme activity is reduced approx. 2-fold upon preincubation of microsomes with alkaline phosphatase. Arrhenius plots of ACAT-activity are curvilinear, with curvatures considerably affected by the acclimation temperature of the fish. Carp HMG-CoA reductase has been characterized previously by Teichert and Wodtke ((1987) Biochim. Biophys. Acta 920, 161-170). When measured at 30 degrees C, ACAT activities from 30 degrees C- and 10 degrees C-acclimated carp are identical (approx. 6 pmol/min per mg protein), whilst 'expressed' HMG-CoA reductase activity (18.1 +/- 12.2 pmol/min per mg protein for 30 degrees C-acclimated carp vs. 159.8 +/- 106.6 pmol/min per mg protein for 10 degrees C-acclimated carp) is enhanced 9-fold in the cold environment. This disparity indicates that cold-acclimation results in a massive increase in the capacity for hepatic cholesterol synthesis relative to hepatic cholesterol esterification. At the same time, hepatic compositional analysis reveals identical contents of unesterified cholesterol in either groups of carp but significantly decreased (3-fold) amounts in cholesterol ester (and also in triacylglycerol, 4-fold) in cold-acclimated carp. Moreover, microsomal fractions display lower cholesterol to phospholipid ratios in the cold. In contrast, concentrations of either cholesterol fractions (and of triacylglycerols) in plasma--the mobile compartment for lipoprotein transport--do not differ in cold- and warm-acclimated carp. Based on current concepts of cholesterol metabolism, it is concluded that the cold-enhanced expression of hepatic HMG-CoA reductase activity is a homeostatic response directed against and compensating for a cold-induced but not yet characterized deficiency in hepatic cholesterol availability.

Acclimatization↗

Sublethal copper exposure induces respiratory stress in common and gibel carp but not in rainbow trout.

Rainbow trout, common carp, and gibel carp were exposed to sublethal Cu levels (1.0 or 1.7 microM) for 1 week. In rainbow trout, arterial oxygen tension (P(aO(2))) remained normal and there was no indication of anaerobic metabolism. P(aO(2)) was considerably lower in common and gibel carp and Cu exposure decreased this further. The decrease was transient for common carp but persistent in gibel carp and coincided with an elevation in arterial carbon dioxide tension (P(aCO(2))) indicating that all gas exchange was compromised in both cyprinid species. The disturbed gas exchange resulted in acidosis, which was respiratory and metabolic for common carp but mainly respiratory for gibel carp. Gibel carp produced ethanol as end product of their alternative anaerobic pathway. The hypothesis that hypertrophy and hyperplasia, resulting in increased diffusion distances, are reducing P(aO(2)) appeared invalid. Hypoventilation seems a more likely cause. Ionoregulatory parameters responded more uniform among species. Fast and pronounced decreases in plasma sodium and chloride developed for all three species, independent of the observed gill damage. Rainbow trout lost 20% of their plasma Na in the first 3 days, while common and gibel carp had only lost 13 and 16% respectively at that time. This difference might be crucial when challenged with Cu exposure and allow a fish to survive the first shock phase and supports it the hypothesis that sodium turnover is a key factor in predicting Cu toxicity.

Animals↗

Cyclooxygenase-derived products, rather than nitric oxide, are endothelium-derived relaxing factor(s) in the ventral aorta of carp (Cyprinus carpio).

In some fish blood vessels, the existence of a NO (nitric oxide) system has been reported. We examined the possibility that this NO system acts as an endothelium-derived relaxing factor (EDRF) in carp aorta using the carp aorta alone and in a combined carp-rat aorta donor-detector system. Use of the typical NO stimulating agent in mammal acetylcholine (ACh) only induced constriction of the carp aorta. This response was not modified by denudation or by NO synthesis inhibition with N-nitro-L-arginine methyl ester. Neither the indirect NO stimulating agents bradykinin and histamine nor the direct NO releasers sodium nitroprusside (SNP) and SIN-1 induced vasorelaxation. Both SNP and ACh elevated the cGMP concentration in rat aorta, but not in carp aorta. In the aorta combination set-up, where carp served as a NO donor and rat aorta served as a NO detector, no relaxation of the rat aorta was observed. The calcium ionophore A23187, a known EDRF producer in mammals, induced relaxation of carp aorta through an endothelium- and cyclooxygenase-dependent mechanism. These results indicate that carp aorta does not produce NO as an EDRF nor does it respond to exogenously supplied NO. The major EDRF in carp is apparently a product(s) of cyclooxygenase metabolism.

Acetylcholine↗

Intracellular Ca2+ storage sites in the carp heart: comparison with the rat heart.

The Ca(2+)-releasing mechanisms of the sarcoplasmic reticulum responsible for cardiac muscle contraction in carp were examined and compared with these mechanisms in rats. Morphologically, the ventricular muscles of the carp heart are composed of an outer compact and an inner spongy layer. In the present study, ventricular muscle preparations were obtained from the compact layer of the carp heart, because the spongy layer does not contribute significantly to the overall force of contraction. Electron microscopic observations showed that the sarcoplasmic reticulum in the carp ventricular muscle, compared to that in the rat ventricular muscle, was poorly developed. Consistent with this finding, specific [3H]ryanodine binding to partially purified sarcoplasmic reticulum preparations obtained from carp ventricular muscle as compared with the preparations isolated from the rat ventricular muscle showed a lower affinity and a smaller number of binding sites. Additionally, a higher Ca2+ concentration was required to cause a half maximal stimulation of [3H]ryanodine binding in the carp heart. In skinned ventricular muscle fibers isolated from carp hearts, the caffeine-induced contracture was significantly weaker than that observed in rat hearts. These results suggest that, in carp hearts, the sarcoplasmic reticulum has an important role as a supply source of Ca2+ for muscle contraction, though the storage capacity and/or amount of Ca2+ release in carp was significantly smaller than that in rats.

Animals↗

Effects of dietary zinc levels on zinc concentrations in tissues of common carp.

Common carp always has higher zinc concentration in viscera than other carps. To determine the relationship between the dietary zinc level and zinc concentration in common carp, the fish were fed diets containing 17, 294, 1,007 and 1,974 ppm zinc for 8 weeks, and the zinc concentration in each tissue was measured. It was found that the group of fish fed 17 ppm zinc had the highest growth rate. When the dietary concentration of zinc was lower than 294 ppm, the zinc concentrations in the tissues were similar during the 8 weeks of experiment. The zinc accumulated in the fish when the dietary zinc concentration was higher than 1,007 ppm. Zinc accumulated first in the digestive tract, then in the skeletal tissues and then in skin and muscle. Common carp and silver carp were fed the same diet from hatchling till adult. The results indicated that no matter whether the feed was natural food or artificial feed containing 300 ppm of zinc or artificial feed containing 25 ppm of zinc, the zinc concentrations in common carp were several times higher than silver carp. We concluded that the fact that common carp had higher zinc concentrations than other carps was not caused by the diet, but might arise from the fact that the absorption rate of zinc was higher.

Animals↗

Decontamination effect of electrolysed NaCl solutions on carp.

AIMS: To evaluate the efficacy of electrolysed NaCl solutions (EW) for disinfecting bacterial isolates from carp, and the potential application of EW to reducing the bacterial load in whole carp and carp fillets. METHODS AND RESULTS: EW was produced by using a two-compartment batch-type electrolysed apparatus. Pure cultures (in vitro), whole carp (skin surface) and carp fillets were treated with EW to detect its antimicrobial effects. The anodic solution [EW (+)] completely inhibited growth of the isolates. Furthermore, dipping the fish samples in EW (+) reduced the mean total count of aerobic bacteria on the skin of whole carp and in fillets by 2.8 and 2.0 log(10), respectively. The cathodic solution [EW (-)] also reduced growth of the isolates from carp by ca 1.0 log(10). Moreover, the total counts of aerobic bacteria in whole carp (on the skin) and fillets were reduced by 1.28 and 0.82 log(10), respectively. CONCLUSIONS: EW (+) has a strong bactericidal effect on bacteria isolated from carp. SIGNIFICANCE AND IMPACT OF THE STUDY: Treatment with EW (+) could extend the shelf life of these fish.

Animals↗