During vertebrate evolution, structural changes in red blood cells (RBC) and hemoglobin (Hb), have probably resulted in the importance of blood carbon dioxide transport. The chloride/bicarbonate exchange across the RBC membrane, which is an integral part of the blood CO2 transport process in vertebrates, has been examined on two different species of teleost fish, Euthynnus alletteratus and Thunnus thynnus, at several oxygenation states of erythrocyte HOS (high-oxygenation state, about 90 % of saturation) and LOS (low-oxygenation state, about 15 % of saturation). The results were compared with those observed in human RBC under the same experimental conditions and with the chicken (Gallus gallus) erythrocytes, which have particular modifications at the N-terminus of the band 3 protein (B3). In fish the kinetic measurements have shown a different anion transport in several oxygenation states of erythrocytes, indicating that also at lower levels of vertebrate evolution there exists a modulation of the anionic flow affected by oxygen. The functional correlation of anion transport to changes of parts of the hemoglobin sequence responsible for alterations in the interactions with the cytoplasmic domain of band 3 protein (cdb3) allowed us to suggest a hypothesis about fish physiology. The highest values of kinetic measurements observed in fish have been attributed to the metabolic need of the RBC in response to the removal of CO2 that in teleosts is also of endogenous origin.
- MeSH
- dospělí MeSH
- druhová specificita MeSH
- erytrocyty - protein 1 vyměňující anionty fyziologie MeSH
- erytrocyty metabolismus MeSH
- hemoglobiny chemie metabolismus MeSH
- iontový transport fyziologie MeSH
- kur domácí MeSH
- kyslík krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- oxid uhličitý krev MeSH
- rybí proteiny fyziologie MeSH
- tuňák metabolismus MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- zvířata MeSH
The effects of gemfibrozil (GFZ), an antihyperlipidemic agent, on the anionic transport of the human red blood cells (RBC) during the oxygenation-deoxygenation cycle were examined. Gemfibrozil clearly plays a role in the modulation of the anionic flux in erythrocytes; in fact it causes a strong increment of anions transport when the RBCs are in the high-oxygenation state (HOS). Such an effect is remarkably reduced in the lowoxygenation state (LOS). With the aim of identifying the dynamics of fibrate action, this effect has been investigated also in human ghost and chicken erythrocytes. These latter, in fact, are known to possess a B3 (anion transporter or Band 3) modified at the cytoplasmic domain (cdb3) which plays a significant role in the metabolic modulation of red blood cells. The results were analyzed taking into account the well-known interactions between fibrates and both conformational states of hemoglobin i.e. the T state (deoxy-conformation) and the R state (oxy-conformation). The effect of gemfibrozil on anionic influx appears to be due to a wide interaction involving a “multimeric” Hb-GFZ-cdb3 macromolecular complex.
- Klíčová slova
- Sulfate transport, Oxygenation - deoxygenation,
- MeSH
- dospělí MeSH
- erytrocytární membrána MeSH
- erytrocyty metabolismus účinky léků MeSH
- financování organizované MeSH
- gemfibrozil farmakologie MeSH
- hemoglobiny metabolismus MeSH
- hypolipidemika farmakologie MeSH
- indikátory a reagencie MeSH
- kalibrace MeSH
- kinetika MeSH
- konformace proteinů MeSH
- lidé středního věku MeSH
- lidé MeSH
- proteinfosfatasy metabolismus MeSH
- pufry MeSH
- sírany krev MeSH
- spotřeba kyslíku fyziologie účinky léků MeSH
- vanadáty farmakologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
„Proteinase-activated“ receptor-2 (PAR-2) is a G protein-coupled transmembrane receptor with seven transmembrane domains activated by trypsin. It has been shown in the pancreatic tissue that PAR-2 is involved in duct/acinary cells secretion, arterial tonus regulation and capillary liquid content turnover under physiological conditions. These above mentioned structures play an important role during the development of acute pancreatitis and are profoundly influenced by a high concentration of trypsin enzyme after its secretion into the interstitial tissue from the basolateral aspect of acinar cells. Among the other factors, it is the increase of interstitial trypsin concentration followed rapidly by PAR-2 action on pancreatic vascular smooth muscle cells that initiates ischemic changes in pancreatic parenchyma and that finally leads to necrosis of the pancreas. Consequent reperfusion perpetuates changes leading to the acute pancreatitis development. On the contrary, PAR-2 action on both exocrine and duct structures seems to play locally a protective role during acute pancreatitis development. Moreover, PAR-2 action is not confined to the pancreas but it contributes to the systemic vascular endothelium and immune cell activation that triggers the systemic inflammatory response syndrome (SIRS) contributing to an early high mortality rate in severe disease.
- MeSH
- biologická adaptace fyziologie genetika MeSH
- Elasmobranchii fyziologie moč MeSH
- elektroforéza metody využití MeSH
- interpretace statistických dat MeSH
- laktátdehydrogenasy fyziologie genetika metabolismus MeSH
- malátdehydrogenasa fyziologie genetika metabolismus MeSH
- močovina chemie metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
