Is there an optimal haematocrit for rainbow trout, Oncorhynchm mykiss (Walbaum)? An interpretation of recent data based on blood viscosity measurements
| Autor: | R. E. Weber, Rufus M. G. Wells |
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| Rok vydání: | 1991 |
| Předmět: |
biology
animal diseases Blood viscosity Oxygen transport Anatomy Aquatic Science biology.organism_classification body regions Trout Animal science hemic and lymphatic diseases Rainbow trout Hemorheology cardiovascular diseases Ecology Evolution Behavior and Systematics circulatory and respiratory physiology |
| Zdroj: | Journal of Fish Biology. 38:53-65 |
| ISSN: | 1095-8649 0022-1112 |
| DOI: | 10.1111/j.1095-8649.1991.tb03090.x |
| Popis: | The viscosity of blood from rainbow trout was measured following manipulation of haematocrit by bleeding, hypoxia. exercise, and anaesthesia. Blood viscosity when measured at high shear rate (225 s 1) was proportional to haematocrit, but the dependence of viscosity on shear rate was far less for swollen erythrocytes from exercised and anaesthetized trout. Erythrocyte swelling was most marked in exercised and anaesthetized trout, and is a confounding factor when considering the effect of haematocrit on viscosity. The viscosity of blood with variable haematocrit, but constant mean cell Hb concentration, indicated that the relative oxygen transport capacity in trout was optimal at a haematocrit of 30%. Data from this, and earlier studies show that haematocrit in trout is variable and labile, yet none of the haematocrit values following manipulations are less than 85% of optimal. Optimal haematocrit is however, significantly higher than measured values from either cannulated or acutely venesected resting trout. |
| Databáze: | OpenAIRE |
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