Long-term pharmacogenetic activation of vagal preganglionic neurons significantly reduced systolic arterial pressure to 159.8 mmHg compared to 177.6 mmHg in spontaneously hypertensive rats.
Does long-term activation of vagal preganglionic neurons reduce blood pressure in spontaneously hypertensive rats?
Long-term activation of vagal parasympathetic pathways reduces resting arterial pressure and restores autonomic balance in an animal model of neurogenic hypertension.
Absolute Event Rate: 159.8% vs 177.6%
p-value: p=<0.001
BACKGROUND: Arterial hypertension is associated with autonomic nervous system dysfunction. Different interventional strategies have been implemented in recent years for the reduction of sympathetic activity in patients with hypertension. However, the therapeutic benefit of increasing vagal tone in hypertensive patients remains largely unexplored. OBJECTIVE: Here, we describe the effects of long-term activation of vagal neural pathways on arterial pressure, heart rate arterial pressure variability and spontaneous baroreflex sensitivity in spontaneously hypertensive rats (SHR) and normotensive Wistar rats. METHODS: Brainstem vagal preganglionic neurons residing in the dorsal vagal motor nucleus (DVMN) were targeted with a lentiviral vector to induce the expression of an artificial G(s) protein-coupled receptor termed designer receptors exclusively activated by designer drugs (DREADD-Gs). The transduced neurons were activated daily by systemic administration of otherwise inert ligand clozapine-n-oxide. Arterial pressure measurements were recorded in conscious freely moving animals after 21 consecutive days of DVMN stimulation. RESULTS: Resting arterial pressure was significantly lower in SHRs expressing DREADD-Gs in the DVMN, compared with control SHRs expressing enhanced green fluorescent protein. No changes in arterial pressure were detected in Wistar rats expressing DREADD-Gs compared with rats expressing enhanced green fluorescent protein in the DVMN. Pharmacogenetic activation of DREADD-Gs-expressing DVMN neurons in SHRs was accompanied with increased baroreflex sensitivity and a paradoxical decrease in cardio-vagal components of heart rate and systolic arterial pressure variability in SHRs. CONCLUSION: These results suggest that long-term activation of vagal parasympathetic pathways is beneficial in restoring autonomic balance in an animal model of neurogenic hypertension and might be an effective therapeutic approach for the management of hypertension.
Moreira et al. (2018) studied Hypertension (n=24). Pharmacogenetic activation of DVMN neurons (DREADD-Gs + CNO) vs. Control vector (eGFP) + CNO was evaluated on Systolic arterial pressure (SAP) in mmHg (p=<0.001). Long-term pharmacogenetic activation of vagal preganglionic neurons significantly reduced systolic arterial pressure to 159.8 mmHg compared to 177.6 mmHg in spontaneously hypertensive rats.