Effects of a parasite-induced nephritis on osmoregulation in the common carp Cyprinus carpio

• Published in: Diseases of aquatic organisms Vol. 50; no. 2; pp. 127 - 135
• Main Authors: MEYER, Claudia, GANTER, Martin, KÖRTING, Wolfgang, STEINHAGEN, Dieter
• Format: Journal Article
• Language: English
• Published: Oldendorf Inter-Research 08.07.2002
• Subjects: Animal aquaculture; Animal productions; Animals; Biological and medical sciences; Carps - blood; Carps - parasitology; Carps - urine; Cyprinus carpio; Electrolytes - urine; Fish Diseases - parasitology; Fish Diseases - physiopathology; Freshwater; Fundamental and applied biological sciences. Psychology; Kinetoplastida; Nephritis - parasitology; Nephritis - physiopathology; Nephritis - veterinary; Osmolar Concentration; Parasitemia - veterinary; Pisciculture; Protozoan Infections - physiopathology; Protozoan Infections, Animal; Time Factors; Trypanoplasma borreli; Vertebrate aquaculture; Water-Electrolyte Balance - physiology; Host parasite relation; Energy metabolism; Protozoal disease; Blood plasma; Freshwater environment; Histopathology; Energetic cost; Pisces; Cyprinus carpio; Parasitemia; Kidney disease; Urine; Protozoa; Urinary system disease; Farming animal; Osmoregulation; Host; Parasitosis; Infection; Vertebrata; Experimental disease; Nephropathy; Parasitism; Cyprinidae; Physicochemical properties; Aquaculture
• DOI: 10.3354/dao050127
• ISSN: 0177-5103

Carp Cyprinus carpio infected with the haemoflagellate Trypanoplasma borreli undergo progressive nephritis associated with a destruction of approx. 40% of the nephric tubules. In an attempt to analyse the effect of the nephritis on the osmoregulation of affected carp, the clinical chemical properties of plasma and urine samples were analysed. Parasitised carp excreted greater amounts of electrolytes in their urine than uninfected carp which excreted highly diluted urine with an osmolality of about 10% of plasma osmolality. During the course of the infection, urine osmolality increased up to 26% of plasma osmolality by Day 21 post-infection (p.i.). The plasma:urine ratio of Na+ also increased, while concomitant losses of Mg2+, Ca2+, K+ and inorganic phosphate were less pronounced. Infected carp were able to maintain a normal solute balance in their plasma. Plasma hydration (indicated by decreased protein contents) occurred on Day 21 p.i. Our data indicate that in T. borreli-infected carp, reabsorption processes of the distal renal tubule were disturbed, while secretory and absorption processes in the proximal tubule appeared to be less affected. In addition, infected carp were able to compensate their increased ion losses, probably by (energy-consuming) active absorption processes. The energy budget of infected carp was additionally affected by a substantial direct consumption of plasma glucose by the parasite.