Whole-body calcium flux rates in cichlid teleost fish Oreochromis mossambicus adapted to freshwater

Journal Article · Tue Oct 01 00:00:00 EDT 1985 · Am. J. Physiol.; (United States)

OSTI ID:6287588

Flik, G; Fenwick, J C; Kolar, Z; Mayer-Gostan, N; Wendelaar Bonga, S E

Radiotracer techniques were used to measure influx and efflux rates of CaS in freshwater-adapted Oreochromis mossambicus. The influx rate of CaS is related to body weight (W) as Fin = 50W0.805 nmol CaS /h. For a 20-g fish the calculated influx rate was 558 nmol CaS /h, and this was attributed largely to extraintestinal uptake since the drinking rate was estimated to be only 28 microliter water/h, which corresponds to an intake of 22.4 nmol CaS /h. The CaS efflux rate was calculated using the initial rate of appearance of radiotracer in the ambient water and the specific activity of plasma CaS . Tracer efflux rates were constant over 6-8 h, which indicated that there was no substantial loss of tracer in either the urine or the feces because this would have resulted in random bursts of tracer loss. Efflux rates then primarily represent integumentary and presumably branchial efflux rates. The efflux rate of CaS is related to body weight as Fout = 30W0.563 nmol CaS /h, which means an efflux rate of 162 nmol CaS /h for a 20-g fish. The net whole-body CaS influx, calculated as Fnet = Fin - Fout, was 396 nmol/h for a 20-g fish, which proves that the ambient water is an important source of CaS .

• Research Organization: Univ. of Nijmegen, Netherland
• OSTI ID: 6287588
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CALCIUM 45
EXCRETION
INTESTINAL ABSORPTION
UPTAKE
CALCIUM COMPOUNDS
FISHES
BIOLOGICAL ADAPTATION
CATIONS
FECES
FRESH WATER
PHYSIOLOGY
URINE
WATER
ABSORPTION
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY FLUIDS
CALCIUM ISOTOPES
CHARGED PARTICLES
CLEARANCE
DAYS LIVING RADIOISOTOPES
EVEN-ODD NUCLEI
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
IONS
ISOTOPES
MATERIALS
NUCLEI
OXYGEN COMPOUNDS
RADIOISOTOPES
VERTEBRATES
WASTES
551001* - Physiological Systems- Tracer Techniques