Autoimplantation of astrocytes into RVLM causes prolonged sympathoinhibition in hypertensive rats

Backgrounds Long considered merely a mechanical support to neurons, astrocytes have been shown to protect and mediate neural function. In stroke‐prone spontaneously hypertensive rats (SHRSP), hypertensive model rats with sympathoexcitation, we previously demonstrated that astrocytes were decreased in the rostral ventrolateral medulla (RVLM). We hypothesized that astrocytes in the RVLM inhibits the activation of sympathetic nervous system (SNS), and examined whether the increase in astrocytes by autoimplantation of astrocytes into the RVLM inhibits the activation of SNS in SHRSP. Methods and Results We divided SHRSP into two groups, astrocyte‐autoimplanted (SHRSP‐A) and control. Astrocytes differentiated from neural stem cell were microinjected into bilateral RVLM of SHRSP‐A group. Telemetrically measured mean arterial pressure (MAP) and urinary norepinephrine excretion (uNE), a parameter of the activation of SNS, were significantly lower in the SHRSP‐A at 14 days after autoimplantation than in the SHRSP‐A at pre‐autoimplantation (MAP; 104±9 mmHg vs. 156±14 mmHg, uNE; 1.1±0.2μg vs. 1.9±0.3μg, n=5 for each, p<0.01 for each). These inhibitions of MBP and activity of SNS were continued for 12 weeks. The mortality rate was significantly lower in the SHRSP‐A than in control. Conclusion Autoimplantation of astrocytes into the RVLM of SHRSP causes prolonged sympathoinhibition in SHRSP.