Autoradiography on erythrokinesis and multihemoglobins in juvenile Salmo salar L. at various respiratory gas regimes

Publisher Website
Google Scholar
Abstract
The kinetics of erylhropoiesis in 5 6 month old Salmo salar L. was correlated to 4 combinations of environmental PO2 and pH/PCO2. Given single doses of 55Fe at the start of continuous flow bioassays, the incorporation was examined in circulating red blood cells (RBC) by autoradiography on blood smears. The proportions of immature, labelled immature and labelled mature erythrocytes were calculated on samples taken at intervals up to 52 days. Compared to control fish kept at a PO2 corresponding to 90% air saturation and pH PCO2 at 7.6/8 pH units/mmHg, oxygen depletion to 50% air saturation stimulated the proliferation of RBC stem cells and enhanced RBC maturation. Ceteris paribus, sustained hypercapnia at a PCO2 in the respiratory water raised to 23 mmHg (pH 7.1–7.2), stimulated proliferation but did not affect the output of mature RBC. Simultaneously lowered PO2 and raised PCO2 to the levels mentioned above obviously stressed the fish, as the effect of lowered PO2per se was not manifested. Radioactivity was traced to all clecdophorelically separable protein fractions from RBC hemolysates. The relevance of blood physiological criteria for probing the fitness or well being of fish in environmental respiratory stress conditions has been discussed.