title: Effect of manipulation of the renin-angiotensin system in control of drinking in juvenile Atlantic salmon (Salmo salar L) in fresh water and after transfer to sea water.
abstract: Drinking in Atlantic salmon (Salmo salar) juveniles was investigated in fresh water and following transfer to sea water. There was a significant effect of fish size on drinking, and smolts (20-30 g) imbibed about ten times less water than alevins of 0.2-0.3 g. Freshwater smolts drank at a rate of 0.15 +/- 0.03 ml.kg-1.h-1 and administration of doses of 10 or 20 mg.kg-1 of papaverine (stimulator of the renin-angiotensin system RAS) or [Asn1, Val5]-Angiotensin II (0.4 mumol.kg-1) resulted in significant increases in drinking, while administration of the angiotensin converting enzyme inhibitor, enalapril (50 mg.kg-1) had no effect on drinking. Transfer of Atlantic salmon smolts to 1/3, 2/3 and full strength sea water resulted in significant increases in drinking to 1.06 +/- 0.12, 1.24 +/- 0.0.16 and 3.89 +/- 0.28 ml.kg-1.h-1, respectively. In sea water, stimulation of the endogenous RAS by administration of papaverine (20 mg.kg-1) resulted in a 20% increase in drinking, while administration of enalapril to doses of 50 and 200 mg.kg-1 lowered drinking to 1.99 +/- 0.48 and 0.32 +/- 0.06 ml.kg-1.h-1, respectively. All treatments were without effect on blood plasma levels of Na+ and Cl- in fresh water, while in sea water smolts both stimulation and inhibition of drinking resulted in hemoconcentration of Na+ and Cl-. The role of the renin angiotensin system in control of drinking and hydromineral balance in Atlantic salmon is discussed.
authors.affiliation: Department of Biological Sciences, University of Dundee, Scotland, UK.
authors.forename: J
authors.initials: J
authors.lastname: Fuentes
authors.forename: F B
authors.initials: FB
authors.lastname: Eddy
mesh_terms: D000804:Angiotensin II / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001835:Body Weight; D002712:Chlorides / Q000097:blood; D004326:Drinking / Q000187:drug effects / Q000502:physiology*; D005618:Fresh Water; D010208:Papaverine / Q000494:pharmacology; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology*; D012474:Salmon / Q000033:anatomy & histology / Q000097:blood / Q000502:physiology*; D012623:Seawater; D012964:Sodium / Q000097:blood
chemical_list: D002712:Chlorides; C101568:angiotensin II, Asn(1)-Val(5)-; D000804:Angiotensin II; D012964:Sodium; D010208:Papaverine