The purpose of the present study was to examine the kinetic process of hemoglobin (Hb) carrying and releasing oxygen. Under the standard conditions (pH 7.4, Po(2) 20 mmHg, 20 °C) the blood samples of chicken, rabbit, frog and carp were equilibrated in oxygen content analyzer with calibrated gas mixture A (0.5% CO(2) and 99.5% N(2)). Then the blood samples were exposed to gas mixture B (21% O(2), 0.5% CO(2) and 78.5% N(2)). After equilibration, the blood samples were exposed to gas mixture A again. During the whole process, Po(2) of blood samples was detected in real-time. The time spent in blood Po(2) changing from 0 to 21 kPa was recorded carefully. The results indicated that the kinetic curve of Hb carrying oxygen presented a shape of "S". It was similar to the Hb oxygen dissociation curve (Hb ODC). Based on the curve, T(50), a new kinetic parameter, was established. T(50) is the time of 50% O(2) saturation of Hb. It can reflect the efficiency of Hb carrying oxygen. Through comparing of T(50), the efficiency of Hb carrying oxygen among 4 species of animals was: frog < carp < rabbit < chicken. In the phase I of Hb carrying and releasing oxygen kinetic curve, the slope in carp was much larger than that in rabbit; the time [(1 411±6) s] of Hb releasing oxygen in chicken was longer than that in other 3 animals. These differences reflected the variety of efficiency of Hb carrying and releasing oxygen. In addition, the kinetic features of Hb carrying oxygen were likely to become an important index to evaluate the function of Hb carrying oxygen, especially in evaluating the ability of artificial blood substitute. On the basis of the analysis of the kinetic curve of Hb carrying oxygen and Hb ODC, another new important efficacy parameter E(50) was proposed. E(50) reflects the relationship between the time of 50% O(2) saturation of Hb and environmental Po(2). E(50) can be used as a synthetic index to assess the efficiency of Hb carrying oxygen.
Animals ; Anura ; Carps ; Chickens ; Hemoglobins ; metabolism ; Hydrogen-Ion Concentration ; Kinetics ; Oxygen ; metabolism ; Rabbits

The regional distribution and relative frequency of some endocrine cells in the pancreas of the carp, Cyprinus carpio Linnaeus, belonging to the family Cyprinidae in the order Cypriniformes, were observed using specific mammalian antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP) by peroxidase antiperoxidase (PAP) method. The pancreas was divided into four regions (principal and secondary islets, exocrine and pancreatic duct regions). In addition, the pancreatic islet regions were further subdivided into three regions (central, mantle and peripheral regions) and the pancreatic duct regions were subdivided into two regions (epithelial and subepithelial regions). Spherical to spindle or occasionally round to oval shaped immunoreactive (IR) cells were demonstrated in the pancreatic islets, exocrine and pancreatic duct. In the principal islet regions, some cells were also detected in the other regions, most of insulin- and somatostatin-IR cells were located in the central regions, and glucagon- and hPP-IR cells were situated in the peripheral regions. In this regions, insulin-IR cells were most predominant cell types and then, glucagon, somatostatin and hPP in that order. In the secondary islet regions, the regional distribution and relative frequency of these four types of endocrine cells were quite similar to those of the principal islets except for cell clusters consisted of hPP-IR cells that were situated in the peripheral to mantle regions. In the pancreatic duct regions, all four major pancreatic endocrine cells were demonstrated in the inter-epithelial cells and/or basal regions of the epithelial linning. In addition, cell clusters composed of numerous insulin-, moderate glucagon- and somatostatin-IR cells of low frequency were also observed in the subepithelial regions of the pancreatic duct. In the exocrine regions, insulin-, glucagon-, somatostatin- and hPP-IR cells were located in the inter-acinus regions with rare, a few, moderate and moderate frequencies, respectively. In conclusion, the regional distribution and relative frequency of four major pancreatic endocrine cells, insulin-, glucagon-, somatostatin- and hPP-IR cells, in the pancreas of the carp showed general patterns which were observed in other stomachless teleost. However, some species- dependent different distributional patterns and/or relative frequencies were also demonstrated.
Animals ; Carps/*metabolism ; Female ; Glucagon/metabolism ; Immunohistochemistry/veterinary ; Insulin/metabolism ; Male ; Pancreas/cytology/*metabolism ; Pancreatic Polypeptide/metabolism ; Somatostatin/metabolism

As one of the most important aquatic fish, Micropterus salmoides suffers lethal and epidemic disease caused by rhabdovirus at the juvenile stage. In this study, a new strain of M. salmoides rhabdovirus (MSRV) was isolated from Yuhang, Zhejiang Province, China, and named MSRV-YH01. The virus infected the grass carp ovary (GCO) cell line and displayed virion particles with atypical bullet shape, 300-500 nm in length and 100-200 nm in diameter under transmission electron microscopy. The complete genome sequence of this isolate was determined to include 11 526 nucleotides and to encode five classical structural proteins. The construction of the phylogenetic tree indicated that this new isolate is clustered into the Vesiculovirus genus and most closely related to the Siniperca chuatsi rhabdovirus. To explore the potential for a vaccine against MSRV, a glycoprotein (1-458 amino acid residues) of MSRV-YH01 was successfully amplified and cloned into the plasmid pFastBac1. The high-purity recombinant bacmid-glycoprotein was obtained from DH10Bac through screening and identification. Based on polymerase chain reaction (PCR), western blot, and immunofluorescence assay, recombinant virus, including the MSRV-YH01 glycoprotein gene, was produced by transfection of SF9 cells using the pFastBac1-gE2, and then repeatedly amplified to express the glycoprotein protein. We anticipate that this recombinant bacmid system could be used to challenge the silkworm and develop a corresponding oral vaccine for fish.
Animals ; Baculoviridae/metabolism* ; Bass/metabolism* ; Carps/virology* ; Cell Line ; Female ; Genetic Techniques ; Genome, Viral ; Glycoproteins/biosynthesis* ; Insecta ; Ovary/virology* ; Phylogeny ; Plasmids/metabolism* ; Recombinant Proteins/biosynthesis* ; Rhabdoviridae/metabolism*

In the present study, the modulatory effect of AMPA receptors on gamma-aminobutyric acid (GABA) transporter current was investigated on enzymatically isolated horizontal cells of carp retina. The GABA transporter current elicited by 1 mmol/L GABA was decreased immediately after pre-application of AMPA (30 mumol/L or 3 mmol/L) for 50 s. Application of 10 mmol/L BAPTA in intracellular solution inhibited the suppression effect of AMPA on GABA transporter current. The suppression effect induced by co-application of 3 mmol/L AMPA and 3 mmol/L NMDA was similar to that of 3 mmol/L AMPA or 3 mmol/L NMDA alone. These results suggest that the activation of AMPA receptors inhibits GABA transporter-mediated current by affecting intracellular Ca(2+) processes in the retinal horizontal cells, which is identical with the modulatory effect of NMDA receptors on GABA transporters.
Animals ; Carps ; Egtazic Acid ; analogs & derivatives ; pharmacology ; GABA Plasma Membrane Transport Proteins ; metabolism ; Receptors, Ionotropic Glutamate ; metabolism ; Retinal Horizontal Cells ; metabolism ; gamma-Aminobutyric Acid ; pharmacology

Calcium is one of the most versatile intracellular second messengers, which plays crucial roles in many intracellular signaling pathways. Researches on intracellular calcium distribution, regulation and function are important for our understanding of cellular physiology. In this mini-review, the regulation of intracellular calcium signal in retinal horizontal cells and the relevant physiological functions were introduced based on the experiments carried out in our laboratory. Intracellular calcium dynamics following the activation of AMPA and NMDA receptors were introduced based on our experiments performed on carp retinal horizontal cells using calcium imaging technique and computational methods. An initial peak response was observed in both cases, which indicated an active participation of intracellular calcium store during the calcium dynamics initiated by AMPA/NMDA receptor activation. Intracellular recording experiments indicated that calcium signaling was crucial for the gradual enhancement of the retinal horizontal cell's responsiveness in exposure to repetitive red flashes. Possible roles of intracellular calcium signaling in the regulation of GABA transporter activity were also introduced based on our whole-cell recording experiments performed on isolated carp retinal horizontal cells.
Animals ; Calcium ; metabolism ; Calcium Signaling ; Carps ; Cells, Cultured ; Patch-Clamp Techniques ; Receptors, AMPA ; metabolism ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Retinal Horizontal Cells ; physiology

To evaluate the public health risk of exposure to microcystins in fish food in China, the distribution pattern of microcystin-LR and microcystin-RR in various organs (liver, intestine, kidney, muscle and lipid) of the dominant freshwater phytoplanktivorous fish Hypophthalmichthys molitrix in Hangzhou, China's Tiesha River was investigated with the method of HPLC-ESI-MS analysis. The distribution of microcystins was different in the fish organs and the major total microcystins (microcystin-LR and microcystin-RR) were present in the intestines (6.49 micro g/g fresh weight), followed by the livers (4.52 micro g/g fresh weight) and the muscles (2.86 micro g/g fresh weight). Microcystins were detected in kidneys (1.35 micro g/g fresh weight), but not detected in lipid. The results suggested that the mean daily intake from fish was 0.03 micro g/kg body weight which was very close to the recommended WHO tolerable daily intake (TDI) level of 0.04 micro g/kg body weight per day, and local people were warned they may have health risk if they consumed fish from the river.
Animals ; Carps ; metabolism ; parasitology ; Fresh Water ; analysis ; parasitology ; Microcystins ; metabolism ; Organ Specificity ; Phytoplankton ; metabolism ; Risk Assessment ; methods ; Risk Factors ; Tissue Distribution ; Water Pollutants, Chemical ; analysis

OBJECTIVETo evaluate the androgenic and anti-androgenic effects of GH (growth hormone) transgenic carp in male rats.

METHODSHershberger assay was carried out in castrated male SD rats aged 4-5 weeks. Testosterone propionate (TP) (0.4 mg/kg BW) was administrated for a positive control, GH transgenic carp (3.0 g/kg BW)+TP (0.4 mg/kg BW), parental carp (3.0 g/kg BW) + TP (0.4 mg/kg BW), and flutamide (Flu) (3.0 g/kg BW) were used for negative controls, and vehicle was administered orally for a blank control. All groups were administrated for 10 consecutive days. At the end of the test, animals were anesthetized, then weights of accessory sex organ were measured. Serum testosterone (T), luteinizing hormone (LH), and Follicle-Stimulating Hormone (FSH) levels were detected.

RESULTSThe weights ratios of the accessory sex organs and body weights showed no significant differences between the solvent control and the GH transgenic carp-treated groups. Serum concentrations of FSH, LH, and T of the rats treated with GH transgenic carp + TP showed no significant changes, compared with those treated with TP only.

CONCLUSIONGH transgenic carp does not have any androgenic agonist or antagonist properties in vivo screening tests.

Animals ; Animals, Genetically Modified ; Carps ; genetics ; Follicle Stimulating Hormone ; blood ; Genitalia, Male ; drug effects ; Growth Hormone ; genetics ; metabolism ; pharmacology ; Luteinizing Hormone ; blood ; Male ; Rats ; Testosterone ; blood

OBJECTIVETo investigate the hispathological characteristics and antioxidant responses in liver of silver carp after intraperitoneal administration of microcystins (MCs) for further understanding hepatic intoxication and antioxidation mechanism in fish.

METHODSPhytoplanktivorous silver carp was injected intraperitoneally (i.p.) with extracted hepatotoxic microcystins (mainly MC-RR and -LR) at a dose of 1000 microg MC-LReq./kg body weight, and liver histopathological changes and antioxidant responses were studied at 1, 3, 12, 24, and 48 h, respectively, after injection.

RESULTSThe damage to liver structure and the activities of hepatic antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxide (GPX) were increased in a time-dependent manner.

CONCLUSIONIn terms of clinical and histological signs of intoxication and LD50 (i.p.) dose of MC-LR, silver carp appears rather resistant to MCs exposure than other fishes. Also, the significantly increased SOD activity in the liver of silver carp suggests a higher degree of response to MCs exposure than CAT and GPX.

Animals ; Antioxidants ; metabolism ; Carps ; metabolism ; Catalase ; metabolism ; Glutathione Peroxidase ; metabolism ; Injections, Intraperitoneal ; Liver ; drug effects ; enzymology ; pathology ; Microcystins ; administration & dosage ; isolation & purification ; pharmacology ; Phytoplankton ; physiology ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism ; Survival Analysis ; Time Factors

It was previously found that the efficacy of synaptic transmission between retinal cone systems and luminosity-type horizontal cells (LHCs) was activity-dependent. Repetitive activation of red-cone pathway increased the LHCos hyperpolarizing response to red light, and the response enhancement was reversible. In this study, intracellular recording and pharmacological method were applied to investigate the mechanism(s) underlying red-flickering-induced response enhancement. Lowering intracellular Ca(2+) in the LHC by intracellular injection of Ca(2+) chelator EGTA prevented the development of red-flickering-induced response enhancement, which implicates the importance of postsynaptic calcium signal. The response enhancement could also be eliminated by a potent antagonist of Ca(2+)-permeable AMPA receptor (CP-AMPAR), which suggests the possibility that Ca(2+) influx via glutamate-gated calcium channels is related to the changes of [Ca(2+)](i). Furthermore, the administration of ryanodine or caffeine also attenuated the phenomenon, which gives evidence that the local calcium signal caused by intracellular calcium-induced calcium release (CICR) may be involved. Taken together, our data implicate that postsynaptic CICR and CP-AMPAR are related to the activity-dependent response enhancement.
Animals ; Caffeine ; pharmacology ; Calcium ; metabolism ; Carps ; Neuronal Plasticity ; physiology ; Receptors, AMPA ; physiology ; Retina ; cytology ; Retinal Cone Photoreceptor Cells ; physiology ; Ryanodine ; pharmacology ; Ryanodine Receptor Calcium Release Channel ; physiology ; Signal Transduction ; physiology ; Synapses ; physiology