scholarly journals THE EFFECTS OF BRANCHIAL CHLORIDE CELL PROLIFERATION ON RESPIRATORY FUNCTION IN THE RAINBOW TROUT ONCORHYNCHUS MYKISS

1994 ◽  
Vol 197 (1) ◽  
pp. 47-63
Author(s):  
S Bindon ◽  
K Gilmour ◽  
J Fenwick ◽  
S Perry
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Partial Pressure ◽  
Respiratory Function ◽  
Chloride Cell ◽  
Control Fish ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Arterial Blood ◽  
Environmental Hypoxia ◽  
Treated Fish

The objectives of this study were to induce chloride cell (CC) proliferation on the gill lamellae of rainbow trout Oncorhynchus mykiss and to evaluate the consequences for respiratory function. Chronic elevation of hormone levels was used to induce CC proliferation; fish were injected with a combination of cortisol (8 mg kg-1 intramuscularly every day for 10 days) and ovine growth hormone (2 mg kg-1 intraperitoneally every second day for 10 days). The extent of CC proliferation was quantified using scanning electron microscopy and a two-dimensional analysis. An extracorporeal preparation in combination with environmental hypoxia was used to assess the effects of CC proliferation on respiratory function. Arterial blood was routed from the coeliac artery through an external circuit in which pH (pHa), partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were monitored continuously. Environmental hypoxia was imposed by gassing a water equilibration column supplying the experimental chamber with N2. The hormone treatment increased the average CC surface area by 2.7-fold and CC density by 2.2-fold; the combined effect was a fivefold increase in CC fractional area. While the PaO2 values of hormone-treated and control fish were similar at PwO2>12.0 kPa, the arterial O2 tensions of treated fish were significantly lower than those of the control group for PwO2¾12.0 kPa. In comparison with control fish at all environmental O2 tensions, the hormone-treated fish exhibited elevated PaCO2 values and a significant acidosis. The effects of CC proliferation on blood gas variables in hormone-treated fish were accompanied by a significantly elevated ventilation amplitude and a lowered ventilation frequency. The results of this study demonstrated (i) that impairment of respiratory gas transfer coincides with CC proliferation, (ii) that O2 and CO2 transfer are influenced differently and (iii) that partial compensation is achieved through physiological adjustments.

Branchial chloride cell proliferation in the rainbow trout, Oncorhynchus mykiss: implications for gas transfer

1994 ◽  
Vol 72 (8) ◽  
pp. 1395-1402 ◽  
Author(s):  
Shawn D. Bindon ◽  
James C. Fenwick ◽  
Steve F. Perry
Keyword(s):  
Electron Microscopy ◽  
Cell Proliferation ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Surface Area ◽  
Chloride Cell ◽  
Gas Transfer ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Treated Fish ◽  
Fractional Surface

The effects of branchial chloride cell proliferation on ion transport capability and gill morphometry were evaluated in the rainbow trout, Oncorhynchus mykiss, to test the hypothesis that chloride cell (CC) proliferation benefits ionic regulation at the expense of efficient gas transfer. The extent of hormone-induced CC proliferation (using ovine growth hormone (oGH), cortisol, or a combination of both) on the gill filament epithelium was assessed by determining the fractional surface area of exposed cells using scanning electron microscopy. Cortisol and oGH were equally effective in increasing CC fractional surface area (~2×), owing to the enlargement of individual CCs. The combined cortisol/oGH treatment resulted in an even greater increase in CC fractional area (~6×), as both the size and number of CCs increased. Sham injections were without effect on CC surface area or number. Significant increases in Na+ (Jin Na+) and Cl− uptake (Jin Cl−) were observed after all hormone treatments and were correlated positively with the increases in the CC fractional surface area. These findings support the view that CC proliferation enhances branchial ion transport capability. Lamellar epithelial thickness (measured by transmission electron microscopy) was increased in hormone-treated fish, while lamellar surface area (measured using light microscopy) was unaffected. The area of the interlamellar water channels (calculated from light micrographs) was significantly reduced in hormone-treated fish. These results suggest that, in trout, a compromise is made between the efficiency of ion regulation and gas transfer in which the enlargement/proliferation of CCs may impede gas transfer.

scholarly journals Immune Response of Rainbow Trout (Oncorhynchus mykiss) to Selected Antigens of Yersinia ruckeri

2009 ◽  
Vol 78 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Unal Ispir ◽  
H. Bayram Gokhan ◽  
Mikail Ozcan ◽  
Mustafa Dorucu ◽  
Naim Saglam
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Metabolic Activity ◽  
Control Fish ◽  
Phagocytic Index ◽  
Control Group ◽  
Yersinia Ruckeri ◽  
Whole Cells ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Fish Group

In this study, effects of Yersinia ruckeri antigens on the immune mechanisms of rainbow trout (Oncorhynchus mykiss) were examined. The weight of the 120 fish used in this study was 20–30 g. After injecting 1 mg of formalin-inactivated whole cells (FKC) and O-antigen (Ag-O) intraperitoneally, blood was taken from the caudal vein of anaesthetized fish and metabolic activity of leukocytes (Nitroblue tetrazolium (NBT) activities), phagocytic activity (PA), phagocytic index (PI), serum protein and serum total immunoglobulin (TIg) levels were determined on day 30 after the first immunization. The same procedure was conducted in the control group. In all the experimental groups, considerable increases in the immune indicators were found and significant differences detected between the control and experimental groups (p < 0.05). Metabolic activity of leukocytes decreased significantly (p < 0.05) during the following treatment with antigens compared to the control fish group.

The adrenergic volume changes of immature and mature rainbow trout (Oncorhynchus mykiss) erythrocytes

2000 ◽  
Vol 203 (19) ◽  
pp. 3025-3031 ◽  
Author(s):  
T. Lecklin ◽  
A. Tuominen ◽  
M. Nikinmaa
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Large Fraction ◽  
Control Fish ◽  
Volume Distribution ◽  
Volume Changes ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Before And After ◽  
Volume Response ◽  
Fluorescence Polarisation

In this study, we examined whether the adrenergic volume response of teleost erythrocytes is related to cell maturity. Rainbow trout (Oncorhynchus mykiss) were made anaemic by reducing their haematocrit to approximately 50 % of the original value. After 3–4 weeks, small, young erythrocytes were seen in the circulation. By measuring the volume distribution of blood samples from anaemic fish before and after noradrenaline stimulation (10 min, 10(−5)mol l(−1) final concentration), we were able to show that the volume response of young, immature erythrocytes to catecholamine stimulation was greater than that of mature erythrocytes. In addition, the membrane fluidity, measured using the steady-state fluorescence polarisation method, was greater in anaemic fish after 24 days of recovery from bleeding than in control fish. Since blood from anaemic fish contained a large fraction of immature erythrocytes, this result indicates that the fluidity of the membrane of immature erythrocytes is greater than that of mature erythrocytes.

Effects of Intermittent Chloramine-T Exposure on Growth, Serum Biochemistry, and Fin Condition of Juvenile Rainbow Trout (Oncorhynchus mykiss)

1994 ◽  
Vol 51 (8) ◽  
pp. 1728-1736 ◽  
Author(s):  
Mark D. Powell ◽  
David J. Speare ◽  
Neil MacNair
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Skin Diseases ◽  
Growth Parameters ◽  
Serum Biochemistry ◽  
Control Fish ◽  
Plasma Sodium ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Chloramine T

Chloramine-T is a commonly used therapeutic agent for the treatment of bacterial gill and skin diseases in the intensive aquaculture of salmonids; however, little is known about its effects on healthy fish. Juvenile rainbow trout (Oncorhynchus mykiss) were exposed weekly to 5, 10, and 20 mg active chloramine-T ingredient∙L−1 in a 20-tank replicate flow-through facility. Control fish were treated with tank water only. Growth parameters and haematocrits were taken twice weekly and serum biochemistry was measured on termination of the experiment. Absolute growth rates were suppressed but only statistically significantly in fish treated with 20 mg chloramine-T∙L−1 compared with controls. Fish exposed to 10 and 20 mg chloramine-T∙L−1 showed significant predisposition to an erosive dermatitis of the caudal fin which appeared to be caused by opportunistic pathogens of the genus Pseudomonas spp. and Flavobacter spp. Haematocrits decreased in controls and ail treatments. A significant concentration-dependent decrease in plasma sodium and chloride was observed. Plasma glucose levels did not vary and were similar to those reported for unstressed trout. We recommend that care be taken when using chloramine-T prophylactically and that concentrations of less than 10 mg∙L−1 be used.

Cell-mediated Immune Response of Rainbow Trout (Oncorhynchus mykiss) to Larval Pseudoterranova decipiens (Nematoda; Ascaridoidea) following Sensitization to Live Sealworm, Sealworm Extract, and Nonhomologous Extracts

1993 ◽  
Vol 50 (1) ◽  
pp. 60-65 ◽  
Author(s):  
N. R. Ramakrishna ◽  
M. D. B. Burt ◽  
B. M. MacKinnon
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Cell Function ◽  
Secondary Response ◽  
Control Fish ◽  
Cell Mediated Immunity ◽  
Specific Response ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Pseudoterranova Decipiens ◽  
Test Fish

The delaved-type hypersensitivity (DTH) reaction (an in vivo manifestation of cell-mediated immunity) was studied in rainbow trout (Oncorhynchus mykiss) exposed to sealworm Pseudoterranova decipiens infections. Test fish immunized with sealworm extract and live intact worms, were compared with control fish which received either phosphate-buffered saline (negative control) or nonhomologous cestode or nematode antigens (positive control). Test fish immunized with sealworm extract produced a typical DTH reaction to live sealworm, challenge. The DTH reaction was similar to that in mammals and showed lymphoid and mononuclear cell infiltration. The electron microscopical studies revealed the presence of activated macrophages and plasma cells in the reaction zone. The specific response, following immunization with homologous antigens, supports the existence of T-cell function with anamnesis in rainbow trout exposed to sealworm antigens. However, when the test fish were immunized with live sealworms and later challenged with live sealworms, the secondary response was poor and showed no difference from controls and naive fish.

Branchial Morphological and Endocrine Responses of Rainbow Trout (Oncorhynchus mykiss) to a Long-Term Sublethal Acid Exposure In Which Acclimation Did Not Occur

1993 ◽  
Vol 50 (1) ◽  
pp. 198-209 ◽  
Author(s):  
Céline Audet ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Physiological Data ◽  
Mucous Cells ◽  
Diffusion Distance ◽  
Cell Numbers ◽  
Rainbow Trout Oncorhynchus Mykiss

Changes in branchial morphology and in plasma Cortisol, adrenaline, and noradrenaline were quantified throughout an 81 -d exposure of rainbow trout (Oncorhynchus mykiss) to sublethal acidity (pH 4.8) in artificial soft water and after a 5-h acid challenge (pH 4.0) of naive fish and 81-d acid-preexposed fish. Changes in branchial morphology at pH 4.8 were generally very mild and characterized by slight increases in filamental mucous cells and decreases in lamellar mucous cells. Chloride cell numbers and branchial Na+–K+- and total ATPase activities did not change. The filamental epithelium thickened, but the water–blood diffusion distance in the lamellae decreased during chronic exposure. Cortisol was significantly elevated throughout whereas catecholamines exhibited relatively little response. Response to acute pH 4.0 challenge was similar in naive and 81-d acid-exposed fish: epithelial damage, increase in visible mucous cells, loss of chloride cells by necrosis, and high cortisol levels but no changes in lamellar or filamental epithelial thickness, diffusion distance, ATPase activities, or catecholamine levels. Previously reported physiological data from these same trout demonstrated that sensitization rather than acclimation had occurred. Therefore, these observations support the view that acclimation does not occur in the absence of significant branchial damage and repair.

scholarly journals THE EFFECTS OF HYPOXIA, HYPEROXIA OR HYPERCAPNIA ON THE ACID-BASE DISEQUILIBRIUM IN THE ARTERIAL BLOOD OF RAINBOW TROUT

1994 ◽  
Vol 192 (1) ◽  
pp. 269-284 ◽  
Author(s):  
K Gilmour ◽  
S Perry
Keyword(s):  
Rainbow Trout ◽  
Partial Pressure ◽  
Co2 Uptake ◽  
Acid Base ◽  
Experimental Conditions ◽  
Directed Diffusion ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
External Loop ◽  
Arterial Blood ◽  
Co2 Excretion

An extracorporeal circulation in combination with a stop&shy;flow technique was used to characterize the acid&shy;base disequilibrium in the arterial blood of rainbow trout Oncorhynchus mykiss during environmental hypoxia, hyperoxia or hypercapnia. Arterial blood was routed from the coeliac artery through an external circuit in which pH (pHa), partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were monitored continuously. The stop&shy;flow condition was imposed by turning off the pump which drove the external loop. Water PO2 or PCO2 was adjusted to give the experimental conditions by bubbling N2, O2 or CO2 through a water equilibration column supplying the fish. During normoxia, the arterial blood exhibited a positive acid&shy;base disequilibrium of approximately 0.04 pH units; that is, pH increased over the stop&shy;flow period by 0.04 units. The extent of the imbalance was increased significantly by hypoxia (final PaO2=2.7&shy;3.7 kPa; deltapH=0.05 units). In fish exposed to hyperoxia (final PaO2=47&shy;67 kPa), the direction of the disequilibrium was reversed; pHa declined by 0.03 units. During hyperoxia, CO2 excretion was impaired by 63 % and the PCO2 of postbranchial blood was higher than that of prebranchial blood. It is therefore conceivable that a reversal of the normal, outwardly directed, diffusion gradient for CO2 accounted for the negative disequilibrium; CO2 uptake at the gills would drive plasma CO2/HCO3-/H+ reactions towards CO2 hydration and H+ formation. During hypercapnia, fish exhibited a twofold increase in the positive pH disequilibrium (deltapH=0.06 units). The results of this study confirmed the existence of an acid&shy;base disequilibrium in the arterial blood of rainbow trout and clearly demonstrated that the extent and/or direction of the disequilibrium are influenced by the respiratory status of the fish.

Effects of different ligands on the bioaccumulation and subsequent depuration of dietary Cu and Zn in juvenile rainbow trout (Oncorhynchus mykiss)

2006 ◽  
Vol 63 (2) ◽  
pp. 412-422 ◽  
Author(s):  
Victoria A Kjoss ◽  
Chris M Wood ◽  
D Gordon McDonald
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Metal Accumulation ◽  
Whole Body ◽  
Control Fish ◽  
Dietary Copper ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Control Food ◽  
Cu And Zn

The effects of different ligands on the bioavailability of dietary copper (Cu) and zinc (Zn) to fish have not been thoroughly investigated. We therefore exposed juvenile rainbow trout (Oncorhynchus mykiss; ~200 mg body weight) to control food or to food supplemented with different Cu (~400 µg·g–1 food) or Zn (~1000 µg·g–1 food) compounds. Tissue metal accumulation was compared among groups. Fish fed CuO showed no differences in tissue Cu concentrations relative to control fish, suggesting that Cu was not readily available for uptake in this form. In contrast, Cu in the form of CuSO4, Cu-proteinate, or Cu-lysine was much more available for uptake, resulting in substantial increases in liver, gut tissue, and whole-body Cu concentrations during the loading phase and decreases during depuration, although liver and whole-body levels remained elevated after 2 weeks. We found no differences in tissue Cu accumulation among these three complexes. There were no effects on growth. For Zn, we found no differences among any of the treatments, including controls, in Zn accumulation or growth. Overall, there was homeostasis of whole-body and tissue-specific Zn concentrations despite the large differences in dietary Zn loads.

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