Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
HEMATOCRIT IN OXYGEN-TRANSPORT AND SWIMMING IN RAINBOW-TROUT (ONCORHYNCHUS-MYKISS)
Autore:
GALLAUGHER P; THORARENSEN H; FARRELL AP;
Indirizzi:
SIMON FRASER UNIV,DEPT BIOL SCI BURNABY BC V5A 1S6 CANADA MASSEY UNIV,DEPT ANAT & PHYSIOL N PALMERSTON NEW ZEALAND
Titolo Testata:
Respiration physiology
fascicolo: 2-3, volume: 102, anno: 1995,
pagine: 279 - 292
SICI:
0034-5687(1995)102:2-3<279:HIOASI>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
BLOOD-VISCOSITY; INDUCED POLYCYTHEMIA; PERFORMANCE; EXERCISE; FISH; ERYTHROCYTHEMIA; CIRCULATION; CAPACITY; HYPOXIA; ANEMIA;
Keywords:
ANEMIA; EXERCISE, SWIMMING; FISH, RAINBOW TROUT (ONCORHYNCUS MYKISS); HEMATOCRIT, OPTIMAL, O-2 TRANSPORT; OXYGEN, BLOOD TRANSPORT; POLYCYTHEMIA;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
28
Recensione:
Indirizzi per estratti:
Citazione:
P. Gallaugher et al., "HEMATOCRIT IN OXYGEN-TRANSPORT AND SWIMMING IN RAINBOW-TROUT (ONCORHYNCHUS-MYKISS)", Respiration physiology, 102(2-3), 1995, pp. 279-292

Abstract

The optimal hematocrit (Hct(opt)) hypothesis was tested by altering Hct (and arterial blood oxygen content, Ca-O2) between extreme states of anemia and polycythemia (Hct = 8-55%) in the rainbow trout. Since blood viscosity (eta) effects on cardiac output (Q) and O-2 transport (T-O2) are likely to be greatest when O-2 demand and Q are maximal, we challenged fish to swim to their critical swimming velocity (U-crit) ina swim-tunnel respirometer at 13 degrees C and measured maximal oxygen uptake (V-O2max), maximum Q(Q(max)), and other cardiovascular variables. In addition, experimental temperature was lowered to 5 degrees C to increase eta. Consistent with the Hct(opt) hypothesis, the decreased Ca-O2 in anemic(Hct < 22%) fish caused significant reductions in U-crit and V-O2max. In contradiction to the Hct(opt) hypothesis, and despite an exponential relationship between eta and Hct, maximal T-O2 (T-O2max) and U-crit increased with polycythemia up to Hct 55%. Although there was a peak for V-O2max, it occurred at an Hct (42%) well above the normocythemic range (23-33%). These results clearly demonstrate thateta is not significant in setting normocythemia in rainbow trout. Thenovel finding of an Hct-dependent relationship for exercise-induced arterial hypoxemia may be indicative of a diffusion limitation to normocythemia. We suggest that factors involved in setting normocythemia invertebrates should include diffusion limitations to oxygen transfer in addition to blood viscosity and oxygen transport constraints.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/10/20 alle ore 02:28:45