Fixation Artifacts in Rainbow Trout (Salmo gairdneri) Gills: A Morphometric Evaluation

1989 ◽  
Vol 46 (5) ◽  
pp. 780-785 ◽  
Author(s):  
D. J. Speare ◽  
H. W. Ferguson
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cell ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Histopathological Changes ◽  
Whole Mount ◽  
Gill Lamellae ◽  
Linear Manner ◽  
Morphometric Evaluation ◽  
Fixation Delay

Epithelial capillary separation (E.C.S.) and epithelial cell hypertrophy (E.H.) of the gill lamellae of fish are two histopathological changes frequently described in association with toxic insults. Both of these gill changes increased in a significant linear manner over delay periods of 20–900 s from death to first entering either Bouin's or 10% formalin fixative. E.C.S. also occurred rapidly when gills were examined as whole mount preparations. The presence of occasional necrotic epithelial and chloride cells resembled apoptosis and is not in itself abnormal, nor did the type of fixative used or fixation delay have an effect on their extent. Gills from fish killed by either MS-222 or cervical spinal severance were similar, except that the latter also had multifocal lamellar telangiectasis. We conclude that E.C.S. and E.H. are readily mimicked by preparation and postmortem artifacts that occur rapidly after death when this is caused by either MS-222 or spinal severance. Bouin's fixative should be used to minimize these changes.

Zinc Influx Across the Isolated, Perfused Head Preparation of the Rainbow Trout (Salmo gairdneri) in Hard and Soft Water

1988 ◽  
Vol 45 (12) ◽  
pp. 2206-2215 ◽  
Author(s):  
Douglas J. Spry ◽  
Chris M. Wood
Keyword(s):  
Steady State ◽  
Rainbow Trout ◽  
Hard Water ◽  
Soft Water ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
First Order ◽  
Scanning Electron Micrography ◽  
Primary Substrate ◽  
Stimulation Of

At a waterborne [Zn] of 1.9 mg∙L−1 in hard water (~1 mmol Ca∙L−1), Zn influx across an isolated, saline-perfused head preparation of rainbow trout (Salmo gairdneri) was about 1.5 nmol∙kg−1∙h−1 through the lamellar pathway and about 1 nmol∙kg−1∙h−1 through the filamental route. Flux rates came rapidly to steady state in both pathways. Trout preexposed to artificial soft water (~0.05 mmol Ca∙L−1) for 5 d showed differential stimulation of flux rates to about 42 and 5 nmol Zn∙kg−1∙h−1 through the lamellar and filamental pathways, respectively. Under these conditions, steady-state fluxes across the lamellae did not occur until 15–20 min after the start of perfusion. Preparations from hardwater-acclimated trout tested in soft water gave typical hardwater fluxes showing that these changes in influx were not simply due to acute exposure of the gill surface to low waterborne [Ca]. Influxes in softwater trout, studied over [Zn] from 0.4 to 7.5 mg Zn∙L−1, revealed a saturable, first-order uptake with apparent Jmax and Km of 150 nequiv∙kg−1∙h−1 and 1.5 mg Zn∙L−1 (23 μmol∙L−1), respectively. Because the apparent Km is in the toxic range, Zn is clearly not the primary substrate. Scanning electron micrography revealed hypertrophy and increased apical exposure of chloride cells; this stimulation, coupled with the increase in Zn influx, suggests that chloride cells may be the site of entry of Zn across the gill.

Effects of Diet, Ambient Temperature, and Holding Conditions on Plasma Thyroxine Levels in Rainbow Trout (Salmo gairdneri)

1977 ◽  
Vol 34 (5) ◽  
pp. 677-682 ◽  
Author(s):  
J. F. Leatherland ◽  
C. Y. Cho ◽  
S. J. Slinger
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cell ◽  
Soybean Oil ◽  
Salmo Gairdneri ◽  
Light Phase ◽  
Cell Height ◽  
Significant Difference ◽  
Pelleted Diet ◽  
Soybean Diet ◽  
Significant Diurnal Variation

Rainbow trout (Salmo gairdneri) acclimated to 19 °C and fed a pelleted diet of either 6% soybean oil or 6% tallow fat had similar plasma thyroxine levels (0.62 ± 0.10 and 0.69 ± 0.08 μg/100 ml, respectively), although fish acclimated to 7 °C and fed the soybean diet gave significantly (P < 0.05) higher plasma thyroxine concentration (1.32 ± 0.13 μg/100 ml) than the group fed the tallow fat diet (0.95 ± 0.12 μg/100 ml). The plasma thyroxine concentration in the fish fed the soybean oil diet was significantly (P < 0.01) higher at 7 °C than at 19 °C. There was no significant difference between the two groups of fish given the tallow fat diet. Epithelial cell heights were largest in groups with the highest plasma thyroxine levels. Epithelial cell height in the two groups at 19 °C were similar, but in both groups of fish at 7 °C, the cell height was significantly greater than in either of the groups at 19 °C (P < 0.01 for comparisons of the 19 °C tallow fat diet with both groups of 7 °C acclimated fish and comparison of the two groups on the soybean oil diet; P < 0.05 for comparisons of the 19 °C, soybean oil diet with the group held at 7 °C and given the tallow fat diet). Fish deprived of food for 40 days had a significantly (P < 0.05) lower plasma thyroxine concentration when compared with fish that had been fed daily. There was no significant diurnal variation in plasma thyroxine over the light phase of a 12 h light: 12 h dark photoperiod, nor did the limitation of light entering the aquaria significantly affect plasma thyroxine values. Key words: endocrine, thyroid, Salmo gairdneri, diet, environmental temperature

Ultrastructural and Clinicopathological Studies on the Toxicity of Cationic Acrylamide-based Flocculant to Rainbow Trout

1987 ◽  
Vol 24 (1) ◽  
pp. 34-43 ◽  
Author(s):  
M. Albassam ◽  
J. Moore ◽  
A. Sharma
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cells ◽  
Blood Vessels ◽  
Cell Injury ◽  
Basement Membranes ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Apical Plasma Membrane ◽  
Plasma Sodium ◽  
Secondary Lamellae

Rainbow trout (Salmo gairdneri) of two age groups were exposed to a cationic acrylamide-based flocculant at various concentrations in static bioassay chambers. At lethal concentrations the flocculant produced severe gill alterations in all fish. The principal alterations were necrosis and separation of the respiratory epithelial cells covering secondary lamellae. Many necrotic chloride cells were also seen, their apical plasma membrane was destroyed, and mitochondria were swollen with separated cristae. An influx of a large amount of fluid into the interstitial spaces caused partial or complete separation of subepithelial spaces from the covering epithelial cells and basement membranes of underlying blood vessels. Clinicopathological alterations included marked decreases in blood pH, partial pressure of oxygen, bicarbonate and plasma sodium, and chloride concentrations. Hematocrit, total protein, and blood glucose were increased. Fish exposed to sublethal concentrations had gill alterations characterized by hypercellularity and thickening of the secondary lamellae. These were due to undifferentiated cell proliferation and macrophage and lymphocyte infiltration between the covering epithelial cells and the underlying blood vessels. Macrophages and undifferentiated cells had large phagolysosomes containing cytoplasmic organelles, an indication of cell injury and increased turnover.

A dense cell in the epithelium of the gill lamellae of the fresh-water brook trout, salvelinus fontinalis

1978 ◽  
Vol 36 (2) ◽  
pp. 450-451
Author(s):  
C. M. Morrison
Keyword(s):  
Fresh Water ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Salt Water ◽  
Uranyl Acetate ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Basal Nucleus ◽  
Thin Sections ◽  
Gill Lamellae

Introduction Unspecialized, dark, chloride and mucous cells have been described in the epithelium of the gill lamellae of Salmo gairdneri and the chloride cell of fresh-water Salvelinus fontinalis has been described. In the course of other studies we found another cell type in the epithelium of fresh-water Salvelinus fontinalis, which is described in the following account.Methods Six fresh-water brook trout, and two adapted to salt-water were killed by a blow on the head, and gill filaments were removed, fixed in Karnovsky's fixative then osmium tetroxide, dehydrated in acetone and embedded in epoxy resin. Thin sections for electron microscopy were stained with 25% uranyl acetate in methanol and lead citrate.Observations The epithelial cells described in Salmo gairdneri were also found in Salvelinus fontinalis, but another type was seen in fresh-water Salvelinus fontinalis. These cells were often as large as chloride cells and had a similar shape, but the cytoplasm and basal nucleus were usually darker, round vesicles were present in the apical cytoplasm, and large membrane-bound bodies were often present in the basal cytoplasm (Fig. 1).

Gill morphometry and fish osmoregulation

1989 ◽  
Vol 67 (12) ◽  
pp. 3055-3063 ◽  
Author(s):  
Pierre Laurent ◽  
Nadra Hebibi
Keyword(s):  
Rainbow Trout ◽  
Surface Area ◽  
Surface Density ◽  
Tap Water ◽  
Chloride Cells ◽  
Apical Surface ◽  
Ionic Regulation ◽  
Epithelial Surface ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Gill Lamellae

Morphofunctional parameters were studied during adaptation of rainbow trout (Oncorhynchus mykiss) to different ionic environments: Strasbourg tap water, ion-poor water, and artificial seawater. The gill lamellae displayed large changes in size. Surface area of individual lamellae increased in trout acclimated to ion-poor water or seawater. Conversely, the harmonic mean thickness of the lamellar epithelium decreased in seawater, and to an even greater extent in ion-poor water. The apical surface area of individual branchial filament chloride cells, the number of these cells, and their apical surface density per unit of filament epithelial surface area were calculated in these three conditions. These variables did not differ significantly in Strasbourg tap water or seawater, but increased greatly in ion-poor water. These results are discussed in relation to gill permeability and ionic regulation in fish.

Deposition of aluminum in the gill epithelium of rainbow trout (Salmo gairdneri Richardson) subjected to sublethal concentrations of the metal

1987 ◽  
Vol 65 (3) ◽  
pp. 647-656 ◽  
Author(s):  
John H. Youson ◽  
Christine M. Neville
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cells ◽  
Organic Acid ◽  
Control Fish ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Gill Epithelium ◽  
Epithelial Surface ◽  
X Ray ◽  
Sublethal Concentrations

Rainbow trout (Salmo gairdneri Richardson) were exposed to acid and sublethal concentrations of inorganic aluminum (1.6 μM at pH 6.1; 2.8 μM at pH 5.5, 5.0, and 4.5); aluminum was also administered in combination with organic acid at pH 4.5 and 5.0. The gill epithelium was examined by transmission electron microscopy and by electron probe X-ray microanalysis. Control fish at pH 7.3 without aluminum showed normal morphology but increased acidity and (or) decreased hardness resulted in a greater exposure of chloride cells at the epithelial surface. All fish exposed to aluminum had electron-dense particles on the surface of the respiratory (pavement) epithelial cells and chloride cells of the gills and most cells had these deposits in varying concentrations within cytoplasmic vacuoles and dense bodies. It was shown by X-ray microanalysis that the deposits contained aluminum. Increased acidity did not alter the pattern of distribution of aluminum particles but a heavy concentration of this metal followed the addition of organic acid. The accumulation of aluminum on and within epithelial cells and increased exposure of chloride cells in the gills could reflect decreased oxygen uptake and increased ion loss in trout, and probably are responsible for the toxicity of aluminum to fish in an acid environment.

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