BDNF Downregulates Adrenergic β-Receptor-Mediated Hypotensive Mechanisms in the Paraventricular Nucleus of the Hypothalamus.

BDNF Downregulates Adrenergic β-Receptor-Mediated Hypotensive Mechanisms in the Paraventricular Nucleus of the Hypothalamus. Am J Physiol Heart Circ Physiol. 2019 Oct 11;: Authors: Thorsdottir D, Cruickshank NC, Einwag Z, Hennig GW, Erdos B Abstract Brain-derived neurotrophic factor (BDNF) is upregulated in the paraventricular nucleus of the hypothalamus (PVN) in response to hypertensive stimuli such as stress and hyperosmolality, and BDNF, acting in the PVN plays a key role in elevating sympathetic activity and blood pressure. However, downstream mechanisms mediating these effects remain unclear. We tested the hypothesis that BDNF increases blood pressure in part by diminishing inhibitory hypotensive input from nucleus of the solitary tract (NTS) catecholaminergic neurons projecting to the PVN. Male Sprague-Dawley rats received bilateral PVN injections of viral vectors expressing either green fluorescent protein (GFP) or BDNF and bilateral NTS injections of vehicle or anti-dopamine-β-hydroxylase-conjugated saporin (DSAP), a neurotoxin that selectively lesions noradrenergic and adrenergic neurons. BDNF overexpression in the PVN without NTS lesioning significantly increased mean arterial pressure (MAP) in awake animals by 18.7±1.8 mmHg. DSAP treatment also increased MAP in the GFP group by 9.8±3.2mmHg but failed to affect MAP in the BDNF group, indicating a BDNF-induced loss of NTS catecholaminergic hypotensive effects. In additio...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research