Calcium is an important chemical for the metabolic functions of the cell. It is very important in the cellular process that the amount of calcium is balanced both inside and outside the cell. Calcium balance within the cell is achieved through channels and ATP-dependent pumps in the cell membrane. The plasma membrane calcium pump is the most important ATP-dependent pump that maintains calcium balance within the cell by removing calcium from the cell. The maximum calcium removal rate of PMCA (Vmax) and the amount of calcium released from the pump (Km) are the parameters that are effective in maintaining the calcium balance within the cell. In this study, the kinetic parameters of the PMCA pump of Hyperparathyroid patients were calculated. For this purpose, erythrocytes isolated from the blood of Hyperparathyroid patients were studied. The hemoglobins in the erythrocytes were emptied. These erythrocytes were closed again and erythrocyte ghosts with only cell membranes were obtained. In this study, erythrocyte ghosts were loaded with a buffer containing Indo 1 FF AM calcium indicator and calcium before being closed again. Calcium concentrations in erythrocyte ghosts were calculated from fluorescence intensities under a fluorescent microscope. From the calcium concentrations measured over time, the kinetic parameters of PMCA were calculated from the Michaelis-Menten equation. In Hyperparathyroid patients, Km = 0.45 uM, Vmax = 0.21 uM. According to these results, the PMCA pumice of Hyperparathyroid patients works faster and pumps more Ca out of the cell compared to the control group.

Keywords: Calcium, Indo 1 FF AM, Michaelis- Menten, PMCA