Real-time Microwave Exposure Induces Calcium Efflux in Primary Hippocampal Neurons and Primary Cardiomyocytes.

OBJECTIVE:To detect the effects of microwave on calcium levels in primary hippocampal neurons and primary cardiomyocytes by the real-time microwave exposure combined with laser scanning confocal microscopy. METHODS:The primary hippocampal neurons and primary cardiomyocytes were cultured and labeled with probes, including Fluo-4 AM, Mag-Fluo-AM, and Rhod-2, to reflect the levels of whole calcium [Ca2+], endoplasmic reticulum calcium [Ca2+]ER, and mitochondrial calcium [Ca2+]MIT, respectively. Then, the cells were exposed to a pulsed microwave of 2.856 GHz with specific absorption rate (SAR) values of 0, 4, and 40 W/kg for 6 min to observe the changes in calcium levels. RESULTS:The results showed that the 4 and 40 W/kg microwave radiation caused a significant decrease in the levels of [Ca2+], [Ca2+]ER, and [Ca2+]MIT in primary hippocampal neurons. In the primary cardiomyocytes, only the 40 W/kg microwave radiation caused the decrease in the levels of [Ca2+], [Ca2+]ER, and [Ca2+]MIT. Primary hippocampal neurons were more sensitive to microwave exposure than primary cardiomyocytes. The mitochondria were more sensitive to microwave exposure than the endoplasmic reticulum. CONCLUSION:The calcium efflux was occurred during microwave exposure in primary hippocampal neurons and primary cardiomyocytes. Additionally, neurons and mitochondria were sensitive cells and organelle respectively.