tailieunhanh - Báo cáo khoa học: " Electrolyte Composition of Mink (Mustela vison) Erythrocytes and Active Cation Transporters of the Cell Membrane"

Tuyển tập các báo cáo nghiên cứu về bệnh thú y được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành thú y đề tài: Electrolyte Composition of Mink (Mustela vison) Erythrocytes and Active Cation Transporters of the Cell Membrane. | Acta vet. scand. 2001 42 261-270. Electrolyte Composition of Mink Mustela vison Erythrocytes and Active Cation Transporters of the Cell Membrane By O. Hansen and T. N. Clausen Department of Physiology Aarhus University Ẳrhus and Danish Fur Breeders Research Centre Tvis Holste-bro Denmark. Hansen O Clausen TN Electrolyte composition of mink Mustela vison erythrocytes and active cation transporters of the cell membrane. Acta vet. scand. 2001 42 261-270. - Red blood cells from mink Mustela vison were characterized with respect to their electrolyte content and their cell membranes with respect to enzymatic activity for cation transport. The intra- and extracellular concentrations of Na K Cl- Ca2 and Mg2 were determined in erythrocytes and plasma respectively. Plasma and red cell water content was determined and molal electrolyte concentrations were calculated. Red cells from male adult mink appeared to be of the low-K high-Na type as seen in other carnivorous species. The intracellular K concentration is slightly higher than the extracellular one and the plasma-to-cell chemical gradient for Na is weak though even the molal concentrations may differ significantly. Consistent with the high intracellular Na and low K concentrations a very low or no ouabain-sensitive Na K -ATPase activity and no K -activated pNPPase activity were found in the plasma membrane fraction from red cells. The Cl- and Mg2 concentrations expressed per liter cell water were significantly higher in red cells than in plasma whereas the opposite was the case with Ca2 . The distribution of Cl- thus does not seem compatible with an insidenegative membrane potential in mink erythrocytes. In spite of a steep calcium gradient across the red cell membrane neither a calmodulin-activated Ca2 -ATPase activity nor an ATP-activated Ca2 -pNPPase activity were detectable in the plasma membrane fraction. The origin of a supposed primary Ca2 gradient for sustaining of osmotic balance thus seems uncertain. .