This book draws together the most relevant and recent advances in the area of ionic transport in animals. In particular, it describes the role of modern cell and molecular biology research techniques in this rapidly advancing field. These techniques have led to important advances in our knowledge of cellular mechanisms of ion transporting epithelia, the role and expression of osmoregulatory hormones and a new understanding of whole body salt and water balance.

1 The Ecophysiology of Osmoregulation in Crustacea

1.1 Introduction
1.2 Steady-state strategies
1.3 The development of osmoregulatory capacity
1.4 Brood pouches and osmoregulation
1.5 Environmental effects on crustacean osmoregulation
1.5.1 Effects of external [ion] or salinity
1.5.2 Effects of water pH change on osmoregulation
1.5.3 Effects of ammonia and nitrate
1.5.4 Other factors
1.6 Intraspecific difference in osmoregulation
1.7 Conclusions
References
2 Ambient ions and the voltage across crayfish gills
2.1 Introduction
2.2 Experimental Results
2.2.1 Tap water medium and Amiloride
2.2.2 The effect of Ca2+
2.2.3 The effect of Na+
2.2.4 The effect of Cl-
2.3 Discussion
2.3.1 The TEP and ambient ion
2.3.2 Implication for ion transport systems
References
3 Regulating the micro-environment of ion transporting epithelia: A comparative approach
3.1 Introduction
3.2 Water movements across epithelia
3.3 Secretion by goblet cells
3.4 Exocytosis, swelling and dispersal of mucus
References
4 Osmotic and Ionic Osmoregulation in Cyclostomes
4.1 Introduction
4.2 Hagfish
4.2.1 Volume Regulation
4.3 Lamprey
4.3.1 Osmoregulation in lampreys
4.3.2 The lamprey kidney
4.3.3 Materials and Methods
4.3.4 Freshwater Osmoregulation
4.3.5 Marine Osmoregulation
4.3.6 Renal function
4.3.7 Drinking
4.3.8 Loss of Marine Osmoregulatory Ability after Freshwater Entry
4.4 Control Mechanisms
4.5 Conclusions
4.6 Acknowledgements
References
5 Ion and Water Balance in Elasmobranch Fish
5.1 Introduction
5.2 Gills
5.2.1 Hormonal control
5.3 Kidney
5.3.1 Hormonal control
5.4 Gut
5.5 Rectal gland
5.6 Freshwater and Euryhaline Elasmobranchs
5.7 Acknowledgements
References
6 Gill Chloride Cells Activation by Plasma Osmolarity
6.1 Introduction and Background
6.2 The importance of osmolarity
6.2.1 Changes in plasma osmolarity during the transition to high salinity
6.2.2 Effect of the addition of 50 mOsm of mannitol on the opercular epithelium
6.2.3 Dose response curves for osmolarity versus chloride current and an effect ofCa2+ concentration
6.2.4 Blocking of 2Cl,Na,K cotransporter eliminates the response to mannitol
6.2.5 Presence of the Na+/H+ exchanger and the consequences of its inhibition on the response of mannitol
6.2.6 Presence of the Na+/HCO-3 exchanger and its lack of participation in the hypertonic response
6.2.7 Blocking Cl- channels with DPC
6.2.8 Quantitative microscopy of chloride cells, an imaging analysis
6.2.9 Effects of hypotonic solutions on the chloride current
6.3 Conclusion
References
7 The use of Modern Microscopical Techniques for the Study of Fish Gill
7.1 Introduction
7.2 Quantification of chloride cells
7.2.1 Chloride cell subtypes
7.2.2 Techniques for characterisation and quantification of chloride cells
7.2.3 Development of functional branchial chloride cells in larvae and juveniles
7.2.4 Chloride cell density in adult fish adapted to freshwater or seawater
7.3 Branchial ion transport in freshwater fish
7.3.1 X-ray microanalysis (XRMA)
7.3.2 Intracellular elemental levels of branchial epithelial cells
7.3.3 Cellular location of NaCI+ and CI- uptake
7.3.4 Control and mechanisms of branchial ion transport
7.4 Perspectives
References
8 Transport and Housekeeping of calcium in Fish Gills
8.1 Introduction
8.2 Overcapacity of transporters; Ca2+ transport in stanniectomized eels
8.3 Involvement of carriers in transepithelial Ca2+ transport
8.3.1 Prolactin and Ca2+ transport in tilapia
8.3.2 Cadmium and Ca2+ transport in trout and tilapia
8.3.3 NaCI+/Ca2+-exchanger and transepithelial transport
8.4 Housekeeping
References
9 Drinking in marine, euryhaline and freshwater teleost fish
9.1 Introduction
9.2 The renin-angiotensin system and drinking in teleost fish
9.3 Drinking in freshwater and the role of the RAS
9.4 Drinking in seawater
9.5 Drinking in larvae
9.6 Absorption of water and salts in marine fish
9.7 Effect of cortisol on drinking
9.8 Effect of atrial natriuretic peptide on drinking
9.9 Effect of temperature on drinking
References
10 Teleost Renal Function: Regulation by Arginine Vasotocin and by Angiotensins
10.1 Introduction
10.2 Renin-angiotensin system (RAS)
10.3 Arginine vasotocin (AVT)
References
11 Arginine Vasotocin (AVT) Controls Renal Sodium and Water Excretion in Birds through Interaction with a new ADH Receptor Subtype
11.1 Body fluid homeostasis
11.2 The antidiuretic hormone AVT
11.3 AVT-induced antidiuresis and antinatriuresis
11.4 The renal AVT/AVP receptor in birds
11.5 Conclusions
References
12 Intracellular signalling in salt-secreting cells - Recent Advances in the Avian Nasal Gland Model
12.1 Introduction
12.2 Mechanism of secretion
12.3 Intracellular calcium signalling
12.4 Activation of secretion by intracellular calcium
12.5 Activation of secretion by intracellular cyclic AMP
12.6 Interactions between calcium and cyclic AMP signals
12.7 Conclusions
References.