Ultracytochemical localization of Na+,K+-activated ATPase in chloride cells from the gills of a euryhaline teleost

1979 ◽  
Vol 193 (1) ◽  
pp. 99-129 ◽  
Author(s):  
Seth R. Hootman ◽  
Charles W. Philpott
Keyword(s):  
Chloride Cells ◽  
Euryhaline Teleost

Freeze fracture of the gill epithelium of euryhaline teleost fish

1980 ◽  
Vol 238 (3) ◽  
pp. R207-R212 ◽  
Author(s):  
C. Sardet
Keyword(s):  
Plasma Membrane ◽  
Tight Junctions ◽  
Teleost Fish ◽  
Freeze Fracture ◽  
Chloride Cells ◽  
Gill Epithelium ◽  
Functional Importance ◽  
Seawater Adaptation ◽  
Basolateral Plasma Membrane ◽  
Euryhaline Teleost

We briefly discuss the information one can obtain using freeze fracture. We used this technique to precisely identify the types of junctions that link the cells of the gill epithelium of euryhaline teleosts. In particular we demonstrate that seawater adaptation is characterized by the appearance of new apical tight junctions between chloride cells. Another particularity of these cells, the extensive network of tubules, extension of the basolateral plasma membrane, is shown to be made of repetitive units. We discuss the functional importance of the observations with respect to the adaptation of fish to different salinities.

Development of apical pits in chloride cells of the gills of Pimephales promelas after chronic exposure to acid water

1983 ◽  
Vol 41 ◽  
pp. 462-463
Author(s):  
Richard L. Leino ◽  
Jon G. Anderson ◽  
J. Howard McCormick
Keyword(s):  
Confidence Interval ◽  
Chronic Exposure ◽  
Lake Superior ◽  
Pimephales Promelas ◽  
Chloride Cells ◽  
Fathead Minnows ◽  
Secondary Lamellae ◽  
Untreated Water ◽  
Water Ph ◽  
Flow Through

Groups of 12 fathead minnows were exposed for 129 days to Lake Superior water acidified (pH 5.0, 5.5, 6.0 or 6.5) with reagent grade H2SO4 by means of a multichannel toxicant system for flow-through bioassays. Untreated water (pH 7.5) had the following properties: hardness 45.3 ± 0.3 (95% confidence interval) mg/1 as CaCO3; alkalinity 42.6 ± 0.2 mg/1; Cl- 0.03 meq/1; Na+ 0.05 meq/1; K+ 0.01 meq/1; Ca2+ 0.68 meq/1; Mg2+ 0.26 meq/1; dissolved O2 5.8 ± 0.3 mg/1; free CO2 3.2 ± 0.4 mg/1; T= 24.3 ± 0.1°C. The 1st, 2nd and 3rd gills were subsequently processed for LM (methacrylate), TEM and SEM respectively.Three changes involving chloride cells were correlated with increasing acidity: 1) the appearance of apical pits (figs. 2,5 as compared to figs. 1, 3,4) in chloride cells (about 22% of the chloride cells had pits at pH 5.0); 2) increases in their numbers and 3) increases in the % of these cells in the epithelium of the secondary lamellae.

Metabolism, homeostasis and growth

2017 ◽  
Author(s):  
Derek Burton ◽  
Margaret Burton
Keyword(s):  
Energy Storage ◽  
White Muscle ◽  
External Environment ◽  
Life Cycles ◽  
Fish Growth ◽  
Chloride Cells ◽  
Internal Environment ◽  
Ion Regulation ◽  
Yolk Proteins ◽  
Active Substances

Metabolism consists of the sum of anabolism (construction) and catabolism (destruction) with the release of energy, and achieving a fairly constant internal environment (homeostasis). The aquatic external environment favours differences from mammalian pathways of excretion and requires osmoregulatory adjustments for fresh water and seawater though some taxa, notably marine elasmobranchs, avoid osmoregulatory problems by retaining osmotically active substances such as urea, and molecules protecting tissues from urea damage. Ion regulation may occur through chloride cells of the gills. Most fish are not temperature regulators but a few are regional heterotherms, conserving heat internally. The liver has many roles in metabolism, including in some fish the synthesis of antifreeze seasonally. Maturing females synthesize yolk proteins in the liver. Energy storage may include the liver and, surprisingly, white muscle. Fish growth can be indeterminate and highly variable, with very short (annual) life cycles or extremely long cycles with late and/or intermittent reproduction.

Chloride secretion and conductance of teleost opercular membrane: effects of prolactin

1982 ◽  
Vol 242 (3) ◽  
pp. R380-R389 ◽  
Author(s):  
J. K. Foskett ◽  
T. E. Machen ◽  
H. A. Bern
Keyword(s):  
Active Transport ◽  
Short Circuit ◽  
Chloride Secretion ◽  
Alternative Interpretation ◽  
Chloride Cells ◽  
Dependent Manner ◽  
Transport Pathway ◽  
Accurate Analysis ◽  
Equivalent Circuit Analysis ◽  
Fish Yield

Effects of prolactin on transport properties of opercular membranes from seawater-adapted tilapia, Sarotherodon mossambicus, have been examined. These membranes are high conductance (average Gt approximately 4 mS.cm-2) tissues with short-circuit currents (I) equal to net chloride secretion. Despite high Gt, nonlinear current-voltage relationships suggest that opercular membranes cannot be classified as "leaky" tissues. Variability among membranes is reflected in a linear relationship between I and Gt with a slope equal to 26 mV and the zero-current Gt intercept equal to 0.45 mS.cm-2. Prolactin injections decrease I and Gt in a dose-dependent manner. Phosphodiesterase inhibition, without effect on I in untreated fish, often partially reverses these prolactin effects. Gt-I data from prolactin-treated fish yield a slope of 18 mV and a Gt intercept of 0.10 mS.cm-2. The effects of prolactin are discussed in terms of conventional equivalent circuit analysis. Discrepancies between predictions based on this model and the actual data indicate that an alternative interpretation, based on a heterogeneous cell population, is more accurate. Analysis of this circuit suggests that the ratio of paracellular to active transport pathway conductances associated with chloride cells is constant and that differences in Gt and I are due to parallel changes in these conductances. Prolactin may effectively "remove" chloride cells from these membranes as well as inhibit (reversible by elevated cellular cAMP levels) active transport pathway conductance of remaining cells.

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