Central administration of the β-arrestin-biased agonist TRV027 increased aversion to saline and significantly reduced blood pressure and heart rate in mice with DOCA-salt hypertension.
Does intracerebroventricular TRV027 lower blood pressure and alter fluid intake in a mouse model of DOCA-salt hypertension?
Central administration of the AT1R β-arrestin-biased agonist TRV027 increases saline aversion and lowers blood pressure in a mouse model of salt-sensitive hypertension, suggesting a potential therapeutic role for selective AT1R β-arrestin pathway activation.
Activation of central AT 1 Rs (angiotensin type 1 receptors) is required for the increased blood pressure, polydipsia, and salt intake in deoxycorticosterone acetate (DOCA)–salt hypertension. TRV120027 (TRV027) is an AT 1 R-biased agonist that selectively acts through β-arrestin. We hypothesized that intracerebroventricular administration of TRV027 would ameliorate the effects of DOCA-salt. In a neuronal cell line, TRV027 induced AT 1a R internalization through dynamin and clathrin-mediated endocytosis. We next evaluated the effect of chronic intracerebroventricular infusion of TRV027 on fluid intake. We measured the relative intake of water versus various saline solutions using a 2-bottle choice paradigm in mice subjected to DOCA with a concomitant intracerebroventricular infusion of either vehicle, TRV027, or losartan. Sham mice received intracerebroventricular vehicle without DOCA. TRV027 potentiated DOCA-induced water intake in the presence or absence of saline. TRV027 and losartan both increased the aversion for saline—an effect particularly pronounced for highly aversive saline solutions. Intracerebroventricular Ang (angiotensin) II, but not TRV027, increased water and saline intake in the absence of DOCA. In a separate cohort, blood pressure responses to acute intracerebroventricular injection of vehicle, TRV, or losartan were measured by radiotelemetry in mice with established DOCA-salt hypertension. Central administration of intracerebroventricular TRV027 or losartan each caused a significant and similar reduction of blood pressure and heart rate. We conclude that administration of TRV027 a selective β-arrestin biased agonist directly into the brain increases aversion to saline and lowers blood pressure in a model of salt-sensitive hypertension. These data suggest that selective activation of AT 1 R β-arrestin pathways may be exploitable therapeutically.
Zanaty et al. (2020) studied Deoxycorticosterone acetate (DOCA)-salt hypertension. TRV120027 (TRV027) vs. Vehicle or losartan was evaluated on Relative intake of water versus saline solutions and blood pressure. Central administration of the β-arrestin-biased agonist TRV027 increased aversion to saline and significantly reduced blood pressure and heart rate in mice with DOCA-salt hypertension.