Exacerbated effects of prorenin on hypothalamic magnocellular neuronal activity and vasopressin plasma levels during salt-sensitive hypertension.

EXACERBATED EFFECTS OF PRORENIN ON HYPOTHALAMIC MAGNOCELLULAR NEURONAL ACTIVITY AND VASOPRESSIN PLASMA LEVELS DURING SALT-SENSITIVE HYPERTENSION. Am J Physiol Heart Circ Physiol. 2019 Jul 05;: Authors: Pitra S, Worker CJ, Feng Earley Y, Stern JE Abstract Accumulating evidence supports that the brain renin-angiotensin system (RAS) including prorenin (PR) and its receptor (PRR), two newly discovered RAS players, contribute to sympathoexcitation in salt-sensitive hypertension. Still, whether PR also contributed to elevated circulating levels of neurohormones such as vasopressin (VP) during salt-sensitive hypertension, and if so, what are the precise underlying mechanisms, remains to be determined. To address these questions, we obtained patch-clamp recordings from hypothalamic magnocellular neurosecretory neurons (MNNs) that synthesize the neurohormones oxytocin (OT) and VP in acute hypothalamic slices obtained from sham and DOCA-salt treated hypertensive rats. We found that focal application of PR markedly increased membrane excitability and firing responses in MNNs of DOCA-salt, compared to sham rats. This effect included a shorter latency to spike initiation and increased numbers of spikes in response to depolarizing stimuli, and was mediated by a more robust inhibition of A-type K+channels in DOCA-salt compared to sham rats. On the other hand, the afterhyperpolarizing potential (AHP) mediated by the activation of SK Ca2+-dependent K...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research