Intestinal transport mechanisms and plasma cortisol levels during normal and out-of-season parr–smolt transformation of Atlantic salmon, Salmo salar

Sundell, Kristina; Jutfelt, Fredrik; Ágústsson, Thorleifur; Olsen, Rolf Erik; Sandblom, Erik; Hansen, Tom; Björnsson, Björn Thrándur

doi:10.1016/s0044-8486(03)00127-3

Cited by 111 publications

(119 citation statements)

References 53 publications

Supporting

Mentioning

109

Contrasting

Order By: Relevance

“…The result was consistent in pyloric caecae, middle and posterior intestine, which are all engaged in the absorption of water. Our data therefore suggests a mechanism to account for previous findings of increased iso-osmotic water uptake capacity, J v in isolated intestinal preparations during smoltification [brown trout (Nielsen et al, 1999), Atlantic salmon (Sundell et al, 2003)]. It is possible that in order for the intestine to develop full functionality in water absorption as well as cell volume regulation, all four AQP isoforms may have to be induced simultaneously.…”

Section: Intestinal Aquaporinssupporting

confidence: 64%

“…Euryhaline fish species can move between FW and SW habitats and accordingly are able to complete the major functional changes in their osmoregulatory tissues, as outlined above. Several studies have characterized how salinity changes may induce adjustment in ion-transporter expression in both gill (see Evans et al, 2005) and intestine (Aoki et al, 2003;Seidelin et al, 2000;Sundell et al, 2003;Veillette et al, 2005) whereas expressional changes in ion transporters in renal tissue are equivocal and may differ among species (e.g. McCormick et al, 1989;Tipsmark et al, 2008b).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Aquaporin expression dynamics in osmoregulatory tissues of Atlantic salmon during smoltification and seawater acclimation

Tipsmark

Sørensen

Madsen

2010

Journal of Experimental Biology

139

138

View full text Add to dashboard Cite

SUMMARYOsmotic balance in fish is maintained through the coordinated regulation of water and ion transport performed by epithelia in intestine, kidney and gill. In the current study, six aquaporin (AQP) isoforms found in Atlantic salmon (Salmo salar) were classified and their tissue specificity and mRNA expression in response to a hyperosmotic challenge and during smoltification were examined. While AQP-1a was generic, AQP-1b had highest expression in kidney and AQP-3 was predominantly found in oesophagus, gill and muscle. Two novel teleost isoforms, AQP-8a and -8b, were expressed specifically in liver and intestinal segments, respectively. AQP-10 was predominantly expressed in intestinal segments, albeit at very low levels. Transfer from freshwater (FW) to seawater (SW) induced elevated levels of intestinal AQP-1a, -1b and -8b mRNA, whereas only AQP-8b was stimulated during smoltification. In kidney, AQP-1a, -3 and -10 were elevated in SW whereas AQP-1b was reduced compared with FW levels. Correspondingly, renal AQP-1a and -10 peaked during smoltification in April and March, respectively, as AQP-1b and AQP-3 declined. In the gill, AQP-1a and AQP-3 declined in SW whereas AQP-1b increased. Gill AQP-1a and -b peaked in April, whereas AQP-3 declined through smoltification. These reciprocal isoform shifts in renal and gill tissues may be functionally linked with the changed role of these organs in FW compared with SW. The presence and observed dynamics of the AQP-8b isoform specifically in intestinal sections suggest that this is a key water channel responsible for water uptake in the intestinal tract of seawater salmonids.

show abstract

Section: Intestinal Aquaporinssupporting

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Aquaporin expression dynamics in osmoregulatory tissues of Atlantic salmon during smoltification and seawater acclimation

Tipsmark

Sørensen

Madsen

2010

Journal of Experimental Biology

139

138

View full text Add to dashboard Cite

show abstract

“…Unlike the basolaterally-located Na þ /K þ -ATPase, apical steps for water entry across the mucosa of ceca are not described. Characterization of aquaporins and epithelial permeability, as carried out for intestine of Japanese eel and Atlantic salmon (Aoki et al, 2003;Sundell et al, 2003), warrant attention in ceca and should help to resolve mechanisms of ion and water transport, particularly in pyloric ceca, where nutrient uptake is high (Collie,'85) and is likely to impact osmoregulatory function (Loretz and Pollina, 2000).…”

Section: Discussionmentioning

confidence: 99%

Osmoregulatory physiology of pyloric ceca: regulated and adaptive changes in chinook salmon

et al. 2005

View full text Add to dashboard Cite

Functions of the anatomically obvious, yet peculiar, pyloric ceca of the fish gut have been a source of conjecture for over two millennia since Aristotle hypothesized on digestive utilities. Here, we demonstrate regulated and adaptive changes in osmoregulatory physiology of ceca from chinook salmon (Onchorhynchus tshawytscha). Transfer of salmon from freshwater to seawater (both short- and long-term) significantly stimulated both fluid uptake from 5.1 to 8.3-9.3 microl/cm2/hr and also Na+/K+ -ATPase from 6.5 to 8.3-9.6 micromol/ADP/mg protein/hr. Similar changes were induced with implants of cortisol, which resulted in high physiological cortisol levels in plasma. Ceca, which can number about 200 in chinook salmon, were estimated to account for the majority of fluid uptake capacity of the intestine and, after long-term seawater adaptation, the proportion of uptake capacity was sixfold higher. Transport physiology of ceca is thus under environmental and endocrine control indicative of an important role in salt and water homeostasis.

show abstract

“…Intestinal segments were mounted in Ussing chambers (Grass and Sweetana 1988) modified according to Sundell et al (2003). Chambers were filled with salmon Ringer solution and the temperature was kept at 10°C by a cooling mantle.…”

Section: Ussing Chamber and In Vitro Exposurementioning

confidence: 99%

Damaging effect of the fish pathogen Aeromonas salmonicida ssp. salmonicida on intestinal enterocytes of Atlantic salmon (Salmo salar L.)

et al. 2004

Self Cite

View full text Add to dashboard Cite

In fish, bacterial pathogens can enter the host by one or more of three different routes: (a) skin, (b) gills and (c) gastrointestinal tract. Bacteria can cross the gastrointestinal lining in three different ways. In undamaged tissue, bacteria can translocate by transcellular or paracellular routes. Alternatively, bacteria can damage the intestinal lining with extracellular enzymes or toxins before entering. Using an in vitro (Ussing chamber) model, this paper describes intestinal cell damage in Atlantic salmon (Salmo salar L.) caused by the fish pathogen Aeromonas salmonicida ssp. salmonicida, the causative agent of furunculosis. The in vitro method clearly demonstrated substantial detachment of enterocytes from anterior region of the intestine (foregut) upon exposure to the pathogen. In the hindgut (posterior part of the intestine), little detachment was observed but cellular damage involved microvilli, desmosomes and tight junctions. Based on these findings, we suggest that A. salmonicida may obtain entry to the fish by seriously damaging the intestinal lining. Translocation of bacteria through the foregut (rather than the hindgut) is a more likely infection route for A. salmonicida infections in Atlantic salmon.

show abstract

Intestinal transport mechanisms and plasma cortisol levels during normal and out-of-season parr–smolt transformation of Atlantic salmon, Salmo salar

Cited by 111 publications

References 53 publications

Aquaporin expression dynamics in osmoregulatory tissues of Atlantic salmon during smoltification and seawater acclimation

Aquaporin expression dynamics in osmoregulatory tissues of Atlantic salmon during smoltification and seawater acclimation

Osmoregulatory physiology of pyloric ceca: regulated and adaptive changes in chinook salmon

Damaging effect of the fish pathogen Aeromonas salmonicida ssp. salmonicida on intestinal enterocytes of Atlantic salmon (Salmo salar L.)

Contact Info

Product

Resources

About