Lack of Aquaporin 3 in bovine erythrocyte membranes correlates with low glycerol permeation |
| |
Authors: | Campos Elisa Moura Teresa F Oliva Abel Leandro Paula Soveral Graça |
| |
Institution: | aREQUIMTE, Dep. Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal;bInstituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal;cResearch Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal;dDep. Bioquímica e Biologia Humana, Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal |
| |
Abstract: | In general, erythrocytes are highly permeable to water, urea and glycerol. However, expression of aquaporin isoforms in erythrocytes appears to be species characteristic. In the present study, human (hRBC) and bovine (bRBC) erythrocytes were chosen for comparative studies due to their significant difference in membrane glycerol permeability.Osmotic water permeability (Pf) at 23 °C was (2.89 ± 0.37) × 10−2 and (5.12 ± 0.61) × 10−2 cm s−1 for human and bovine cells, respectively, with similar activation energies for water transport. Glycerol permeability (Pgly) for human ((1.37 ± 0.26) × 10−5 cm s−1) differed in three orders of magnitude from bovine erythrocytes ((5.82 ± 0.37) × 10−8 cm s−1) that also showed higher activation energy for glycerol transport. When compared to human, bovine erythrocytes showed a similar expression pattern of AQP1 glycosylated forms on immunoblot analysis, though in slight higher levels, which could be correlated with the 1.5-fold larger Pf found. However, AQP3 expression was not detectable. Immunofluorescence analysis confirmed the absence of AQP3 expression in bovine erythrocyte membranes.In conclusion, lack of AQP3 in bovine erythrocytes points to the lipid pathway as responsible for glycerol permeation and explains the low glycerol permeability and high Ea for transport observed in ruminants. |
| |
Keywords: | Aquaporin 3 Glycerol permeability Water transport Erythrocyte Bovine |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|