scholarly journals The surface epithelium of teleostean fish gills. Cellular and junctional adaptations of the chloride cell in relation to salt adaptation.

1979 ◽  
Vol 80 (1) ◽  
pp. 96-117 ◽  
Author(s):  
C Sardet ◽  
M Pisam ◽  
J Maetz

Various species of teleostean fishes were adapted to fresh or salt water and their gill surface epithelium was examined using several techniques of electron microscopy. In both fresh and salt water the branchial epithelium is mostly covered by flat respiratory cells. They are characterized by unusual outer membrane fracture faces containing intramembranous particles and pits in various stages of ordered aggregation. Freeze fracture studies showed that the tight junctions between respiratory cells are made of several interconnecting strands, probably representing high resistance junctions. The organization of intramembranous elements and the morphological characteristics of the junctions do not vary in relation to the external salinity. Towards the base of the secondary gill lamellae, the layer of respiratory cells is interrupted by mitochondria-rich cells ("chloride cells"), also linked to respiratory cells by multistranded junctions. There is a fundamental reorganization of the chloride cells associated with salt water adaptation. In salt water young adjacent chloride cells send interdigitations into preexisting chloride cells. The apex of the seawater chloride cell is therefore part of a mosaic of sister cells linked to surrounding respiratory cells by multistranded junctions. The chloride cells are linked to each other by shallow junctions made of only one strand and permeable to lanthanum. It is therefore suggested that salt water adaptation triggers a cellular reorganization of the epithelium in such a way that leaky junctions (a low resistance pathway) appear at the apex of the chloride cells. Chloride cells are characterized by an extensive tubular reticulum which is an extension of the basolateral plasma membrane. It is made of repeating units and is the site of numerous ion pumps. The presence of shallow junctions in sea water-adapted fish makes it possible for the reticulum to contact the external milieu. In contrast in the freshwater-adapted fish the chloride cell's tubular reticulum is separated by deep apical junctions from the external environment. Based on these observations we discuss how solutes could transfer across the epithelium.

2013 ◽  
Vol 73 (3) ◽  
pp. 609-615 ◽  
Author(s):  
FC. Sterzelecki ◽  
E. Rodrigues ◽  
E. Fanta ◽  
CAO. Ribeiro

Eurihaline fish support waters with different salt concentration. However, numerous studies have shown that salinity can affect fish development. Thus, the effect of salinity change from 20 to 5 and 35 on survival, weight, length, gill chloride cell ultrastructure and gill Na+, K+ ATPase activity was evaluated in Centropomus parallelus following short-term (6, 24 and 96 hours) and long-term exposure (30 and 60 days). Salinity did not affect C. parallelus survival, final weight and length. The quantity of chloride cells increased visibly at salinities of 5 and 35, with the cells exhibiting the typical features of uptake and secretory cells, respectively. Na+, K+ ATPase activity in the gill of the C. parallelus was significantly greater at a salinity of 5 than at a salinity of 20 or 35 after 96 hours, but not after 30 or 60 days. These results indicate that salinity change from high to low salt water induces gill chloride cell and Na+, K+ ATPase activity adaptations after short-term exposure. However, after long-term exposure at salinity 5, gill Na+, K+ ATPase activity is no more necessary at high levels. The increase in salinity to 35 does not induce significant change in gills. Juveniles of C. parallelus may thus be capable of acclimating to salinities of 5 to 35 for 60 days without significant effects on development.


1982 ◽  
Vol 56 (1) ◽  
pp. 441-452
Author(s):  
T. Hatae ◽  
E.L. Benedetti

The membrane architecture of the cytoplasmic tubules in lamprey chloride cells has been studied by electron microscopy using thin-section and freeze-fracture techniques. The chloride cell of lampreys (Lampetra japonica, Petromyzon marinus) is largely occupied with a continuous network of cytoplasmic tubules, which are derived from the invagination of the basolateral plasma membrane. The lumenal surface of this tubular network is covered with spirally wound parallel rows of electron-dense material, which consist of linear aggregates of particles. Freeze-fracture of the membrane of the tubules also shows spiral arrangements of particles (approximately 9 nm in diameter) on the P-face and complementary shallow grooves on the E-face. These arrangements of particles are about 17 nm apart and wound at a pitch of about 45 degrees. These complex organizations of the membrane of the tubules are probably the sites of transport of ion and water, which is essential for the maintenance of ionic homeostasis in both low- and high-salinity environments.


1980 ◽  
Vol 238 (3) ◽  
pp. R260-R268 ◽  
Author(s):  
J. P. Girard ◽  
P. Payan

The present study discusses the respective roles of the chloride and respiratory cells in branchial ion exchange in freshwater- and seawater-adapted teleosts. In the gill, two distinct epithelia are defined according to their blood irrigation and cellular characteristics: the primary lamellar epithelium containing mostly chloride cells is functionally connected to the venous compartment; the secondary lamellar epithelium consisting of respiratory cells is irrigated by the arterioarterial circulation. The fundamental reorganization occurring in the chloride cells during adaptation to seawater consists of the appearance of leaky ultrastructure related to an increase in the ionic and nonelectrolyte permeabilities of the primary lamellar epithelium. The physiological functions of respiration, excretion, and the maintenance of acid-base balance occur through the secondary lamellar epithelium both in freshwater and seawater fish. The increase of the exchange diffusion across the secondary lamellar epithelium on seawater adaptation is directly related to the increase in the external salinity. The study of adrenergic control in the teleost gill emphasizes the functional advantage to the fish during adaptation to seawater of the anatomic separation of the osmoregulatory primary lamellar epithelium.


1984 ◽  
Vol 99 (3) ◽  
pp. 875-885 ◽  
Author(s):  
A Saito ◽  
S Seiler ◽  
A Chu ◽  
S Fleischer

We have developed a procedure to isolate, from skeletal muscle, enriched terminal cisternae of sarcoplasmic reticulum (SR), which retain morphologically intact junctional "feet" structures similar to those observed in situ. The fraction is largely devoid of transverse tubule, plasma membrane, mitochondria, triads (transverse tubules junctionally associated with terminal cisternae), and longitudinal cisternae, as shown by thin-section electron microscopy of representative samples. The terminal cisternae vesicles have distinctive morphological characteristics that differ from the isolated longitudinal cisternae (light SR) obtained from the same gradient. The terminal cisternae consist of two distinct types of membranes, i.e., the junctional face membrane and the Ca2+ pump protein-containing membrane, whereas the longitudinal cisternae contain only the Ca2+ pump protein-containing membrane. The junctional face membrane of the terminal cisternae contains feet structures that extend approximately 12 nm from the membrane surface and can be clearly visualized in thin section through using tannic acid enhancement, by negative staining and by freeze-fracture electron microscopy. Sections of the terminal cisternae, cut tangential to and intersecting the plane of the junctional face, reveal a checkerboardlike lattice of alternating, square-shaped feet structures and spaces each 20 nm square. Structures characteristic of the Ca2+ pump protein are not observed between the feet at the junctional face membrane, either in thin section or by negative staining, even though the Ca2+ pump protein is observed in the nonjunctional membrane on the remainder of the same vesicle. Likewise, freeze-fracture replicas reveal regions of the P face containing ropelike strands instead of the high density of the 7-8-nm particles referable to the Ca2+ pump protein. The intravesicular content of the terminal cisternae, mostly Ca2+-binding protein (calsequestrin), is organized in the form of strands, sometimes appearing paracrystalline, and attached to the inner face of the membrane in the vicinity of the junctional feet. The terminal cisternae preparation is distinct from previously described heavy SR fractions in that it contains the highest percentage of junctional face membrane with morphologically well-preserved junctional feet structures.


1994 ◽  
Vol 51 (10) ◽  
pp. 2170-2178 ◽  
Author(s):  
J. Mark Shrimpton ◽  
Nicholas J. Bernier ◽  
George K. Iwama ◽  
David J. Randall

We compared the saltwater tolerance of coho salmon (Oncorhynchus kisutch) juveniles that were reared in different environments. The groups examined consisted of fish reared exclusively in the hatchery, a hatchery group transplanted into the upper watershed of the river (colonized), and wild fish from natural spawning broodstock in the river. Although hatchery fish were much larger than their wild or colonized counterparts, they consistently showed a reduced saltwater tolerance as assessed by a much greater perturbation in plasma sodium concentration following transfer to salt water. Within each group there was no relationship between size of the fish and saltwater tolerance. Following transfer to sea water, hatchery fish showed a significant decline in haematocrit and a significant increase in circulating plasma cortisol concentration. Neither of these changes was seen in wild smolts. Hatchery fish possessed fewer chloride cells, and lower specific activities of the enzymes Na+K+ATPase and citrate synthase. The weaker osmoregulatory ability of hatchery fish led to a greater mortality following abrupt transfer to 35‰ seawater. We believe that the differences in saltwater tolerance seen among the different groups of fish are due to rearing environment.


1993 ◽  
Vol 50 (1) ◽  
pp. 198-209 ◽  
Author(s):  
Céline Audet ◽  
Chris M. Wood

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.


1997 ◽  
Vol 18 (1) ◽  
pp. 67-76 ◽  
Author(s):  
S Marsigliante ◽  
A Muscella ◽  
G P Vinson ◽  
C Storelli

ABSTRACT Immunocytochemistry of paraffin-embedded and cryostat sections of eel (Anguilla anguilla) gill showed that angiotensin II receptors (Ang II-R) were present in chloride cells, uniformly distributed in the cytoplasm and on surface membranes. Computerised image analysis of these preparations showed that gills from sea water (SW)-adapted animals had a significantly (3-fold) higher Ang II-R concentration compared with freshwater (FW)-adapted eel gills. Isoelectric focusing gel electrophoresis revealed two Ang II-R isoforms with pI 6·5 and 6·6 that were differentially modulated by environmental salinity: they were equally abundant in SW while in FW the pI 6·6/pI 6·5 ratio was 1·66. Using catalytic cytochemistry with image analysis, gill chloride cell membrane Na+/K+ATPase activity was shown to increase 4-fold in response to SW adaptation. Additionally, perfusion of gills for 30 min with 0·1, 10 or with 100 nM Ang II provoked a dose-dependent increment in Na+/K+ATPase activity in FW, and a biphasic response in SW gills in which activity was significantly increased at low Ang II concentrations but was reduced to basal values at 100 nM. The data suggest that adaptation to sea water significantly increases Ang II-R concentration in the chloride cell and, together with the effects of Ang II on Na+/K+ATPase activity, suggest a role for this hormone in gill NaCl retention. The different responses of Na+/K+ATPase to Ang II stimulation in FW and SW may be attributed to the presence of two receptor subtypes that are differently modulated by salinity and that have opposing effects on Na+/K+ATPase.


2020 ◽  
Vol 19 (2) ◽  
pp. 173-184
Author(s):  
Sirirat Sathorn ◽  
◽  
Sinlapachai Senarat ◽  
Jes Kettratad ◽  
Gen Kaneko ◽  
...  

Ovoviviparous poeciliid fishes have been relatively well studied in the unique reproductive strategy, but their osmoregulatory system largely remains unknown. In this study, we conducted a short-term (7 days) lab experiment to investigate the effect of different salinity levels from 0 (freshwater) to 50 ppt (mesosaline) on the number of chloride cells and mucus secreting cells of female Poecilia mexicana. The density of chloride cells and mucus secreting cell were also arranged along the epithelial lamellae in wild fish. More interestingly, the average density of chloride cells and the mucus secreting cell were mostly differed between these levels (P < 0.05). Integrative data from our study suggested that the potential function of the osmoregulatory mechanism/strategy was supported by chloride and mucus secreting cells of female P. mexicana gill.


1999 ◽  
Vol 277 (2) ◽  
pp. R517-R522 ◽  
Author(s):  
Chris K. C. Wong ◽  
D. K. O. Chan

The purpose of the present study was to characterize chloride cell subtypes in the fish gill and to monitor the kinetic change of cell division in the gill epithelia during seawater adaptation. Employing a three-step Percoll gradient method, the gill chloride cells and nonchloride cell population were isolated. The isolated cells were studied using multiparameter flow cytometry, recording the changes in 1) cell size, 2) cellular granularity, and 3) cell autofluorescence. Two chloride cell subtypes were identified in the freshwater eels. Within 2–4 days after entering seawater, new subtypes of transitory chloride cell, with bigger cell size and more intense mitochondria autofluorescence, appeared. After full adaptation, two major seawater chloride cell subtypes were again discerned; their sizes were the largest and their mitochondria autofluorescence was the highest. In the second part of the experiment, cell cycle analysis demonstrated a progressive increase in the percentage of gill cells entering the DNA synthesis phase during seawater adaptation, where a small population of mitotic cells was identified in the nonchloride cell population but not in chloride cells. We hypothesize that the mitotic cells identified are stem cells, which will ultimately differentiate into seawater chloride cells. Our results confirm the existence of heterogeneity of chloride cells. Individual subtypes could be isolated in high purity for further studies to elucidate their respective function in mediating ion transport.


Author(s):  
Bert Ph. M. Menco

Olfactory cilia have membranes that contain odorant receptors and an apparatus to transduce the odorous message into a code comprehensible to the rest of the cell and the brain. Membranes of these cilia have a variety of cellsurface proteins to do this. Ultrastructural freeze-fracture and freeze-etch studies have implied that this is really true. Biochemical and electrophysiological studies on olfactory epithelia with lectins have suggested that a major part of these proteins are glycoproteins. Therefore, binding of colloidal-gold conjugated lectins was studied in cilia and microvilli of rat olfactory with cilia and microvilli of nasal respiratory epithelial surfaces as comparison. This was done in sections of rapidly-frozen, freeze-substituted specimens embedded in Lowicryl K11M or, for wheat germ agglutinin ( WGA) alone, in deep-etched replicas. Olfactory dendritic endings and cilia labeled with WGA and, faintly, with soybean agglutinin (SBA); olfactory supporting-celi microvilli bound only Dolichos biflorus agglutinin (DBA). Microvilli of an infrequent cell bound peanut agglutinin (PNA), SBA, and WGA. Relative to olfactory cilia these microvilli labeled more strongly with the last two lectins. The cell resembles a presumptive sensory oneR. Cilia of nasal respiratory cells bound WGA and, somewhat more weakly, PNA; microvilli of respiratory cells bound all four lectins. In respiratory ciliated cells cilia and microvilli of the same cell type showed a quite different pattern of labeling.


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