caa a22 4500 477116957 CHVBK 20180405111625.0 cr unu---uuuuu 170330e19960201xx s 000 0 eng 10.1007/BF01874841 doi (NATIONALLICENCE)springer-10.1007/BF01874841 The effects of experimental anaemia on CO2 excretion in vitro in rainbow trout, Oncorhynchus mykiss [Elektronische Daten] [Kathleen Gilmour, Steve Perry] The effects of severe experimental anaemia on red blood cell HCO3 − dehydrationin vitro were examined in rainbow trout,Oncorhynchus mykiss. After 5 days of anaemia (haematocrit=4.9±1.1%) induced by intraperitoneal injection of phenylhydrazine hydrochloride, fish displayed elevated arterial CO2 tensions (anaemic PaCO2=3.19±0.42 torrvs. control PaCO2=1.35±0.17 torr) and a significant acidosis (anaemic pHa=7.73±0.04vs. control pHa=7.99±0.04). However, after 15-20 days of anaemia (hct=6.6±0.8%) induced by blood withdrawal, the arterial CO2 tension was significantly lower than the control value, suggesting that physiological adjustments occurred within this time period to compensate for the lowered haematocrit. Compensation probably did not involve alterations in ventilation, which was unaffected by 5 days of anaemia (anaemic $$\dot V$$ ;w=786±187 ml min−1 kg−1 vs. control $$\dot V$$ ;w=945±175 min−1 kg−1), based on indirect Fick principle measurements. Potential adaptations to longer term anaemia at the level of the red blood cells were investigated using a radioisotopic HCO3 − dehydration assay. Owing to the difference in haematocrits, the HCO3 − dehydration rate for blood from anaemic fish was significantly lower than that for control fish following equilibration at the same CO2 tension. This difference was eliminated when HCO3 − dehydration rates were measured on blood samples adjusted to the same haematocrit, a result which implies that the intrinsic rate of CO2 excretion at the level of the red blood cell was not ‘up-regulated' during anaemia. The difference was also eliminated by equilibrating the blood samples with CO2 tensions appropriate for the group from which the sample was obtained,i.e., PCO2=1.4 torr for control samples and PCO2=3.2 torr for anaemic samples; each at the appropriate haematocrit. It is concluded that the elevated PaCO2 helps to reset CO2 excretion to the control level, but that some additional physiological adjustment occurs to lower the PaCO2 after 15-20 days of anaemia. Kugler Publication bv, 1996 Oncorhynchus mykiss nationallicence anaemia nationallicence phenylhydrazine nationallicence red blood cell nationallicence CO2 excretion nationallicence HCO3− dehydration nationallicence Cl−/HCO3− exchange nationallicence ventilation nationallicence Gilmour Kathleen Department of Biology, University of Ottawa, 30 Marie Curie, K1N 6N5, Ottawa, Canada aut Perry Steve Department of Biology, University of Ottawa, 30 Marie Curie, K1N 6N5, Ottawa, Canada aut Fish Physiology and Biochemistry Kluwer Academic Publishers 15/1(1996-02-01), 83-94 0920-1742 15:1<83 1996 15 10695 https://doi.org/10.1007/BF01874841 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01874841 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gilmour Kathleen Department of Biology, University of Ottawa, 30 Marie Curie, K1N 6N5, Ottawa, Canada aut NATIONALLICENCE 700 1- Perry Steve Department of Biology, University of Ottawa, 30 Marie Curie, K1N 6N5, Ottawa, Canada aut NATIONALLICENCE 773 0- Fish Physiology and Biochemistry Kluwer Academic Publishers 15/1(1996-02-01), 83-94 0920-1742 15:1<83 1996 15 10695 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer