Department of Applied Physics, The Hebrew University of Jerusalem, Jerusalem, Israel.
Department of Physics, Kazan Federal University, 18 Kremlevskaya St., 420008, Kazan, Russia.
Eur Biophys J. 2022 Jul;51(4-5):353-363. doi: 10.1007/s00249-022-01602-3. Epub 2022 May 9.
Dielectric spectroscopy has been used in the study and development of non-invasive glucose monitoring (NIGM) sensors, including the range of microwave frequencies. Dielectric relaxation of red blood cell (RBC) cytosolic water in the microwave frequency band has been shown to be sensitive to variations in the glucose concentration of RBC suspensions. It has been hypothesized that this sensitivity stems from the utilization of D-glucose by RBCs. To verify this proposition, RBCs were pretreated with inhibitors of D-glucose uptake (cytochalasin B and forskolin). Then their suspensions were exposed to different D-glucose concentrations as measured by microwave dielectric spectroscopy (MDS) in the 500 MHz-40 GHz frequency band. After incubation of RBCs with either inhibitor, the dielectric response of water in the cytoplasm, and specifically its relaxation time, demonstrated minimal sensitivity to the change of D-glucose concentration in the medium. This result allows us to conclude that the sensitivity of MDS to glucose uptake is associated with variations in the balance of bulk and bound RBC cytosolic water due to intracellular D-glucose metabolism, verifying the correctness of the initial hypothesis. These findings represent a further argument to establish the dielectric response of water as a marker of glucose variation in RBCs.
介电谱学已被用于研究和开发非侵入性血糖监测（NIGM）传感器，包括微波频率范围。已经表明，在微波频段，红细胞（RBC）胞质水的介电弛豫对 RBC 悬浮液中葡萄糖浓度的变化敏感。有人假设这种敏感性源于 RBC 对 D-葡萄糖的利用。为了验证这一假设，用 D-葡萄糖摄取抑制剂（细胞松弛素 B 和 forskolin）预处理 RBC。然后，通过微波介电谱（MDS）在 500 MHz-40 GHz 频率范围内测量它们的悬浮液暴露于不同的 D-葡萄糖浓度。在用任一抑制剂孵育 RBC 后，细胞质中水的介电响应，特别是其弛豫时间，对介质中 D-葡萄糖浓度的变化表现出最小的敏感性。该结果使我们能够得出结论，MDS 对葡萄糖摄取的敏感性与由于细胞内 D-葡萄糖代谢导致的胞质水的体相和结合相之间平衡的变化有关，从而验证了初始假设的正确性。这些发现进一步证明了水的介电响应作为 RBC 中葡萄糖变化的标志物的正确性。
