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AIM There is a characteristic neurohumoral activation in heart failure (HF). However, few studies have been performed to examine the role of the central nervous system in the activation of sympathetic outflow during HF. In this paper we review some of our studies, with particular emphasis on examining the role of the paraventricular nucleus (PVN) in the(More)
The paraventricular nucleus (PVN) of the hypothalamus is a central site known to modulate sympathetic outflow. Excitatory and inhibitory neurotransmitters within the PVN dictate final outflow. The goal of the present study was to examine the role of the interaction between the excitatory neurotransmitter glutamate and the inhibitory neurotransmitter GABA in(More)
Neuronal activity in the hypothalamic paraventricular nucleus (PVN), as well as sympathetic outflow from the PVN, is basally restrained by a GABAergic inhibitory tone. We recently showed that two complementary GABA(A) receptor-mediated modalities underlie inhibition of PVN neuronal activity: a synaptic, quantal inhibitory modality (IPSCs, I(phasic)) and a(More)
The paraventricular nucleus (PVN) of the hypothalamus is an important site of integration in the central nervous system for sympathetic outflow. Both glutamate and nitric oxide (NO) play an important role in the regulation of sympathetic nerve activity. The purpose of the present study was to examine the interaction of NO and glutamate within the PVN in the(More)
OBJECTIVES We investigated whether Angiotensin II (Ang II) modulates peripheral chemoreflex function through carotid body (CB) chemoreceptors in chronic heart failure (CHF). METHODS We measured renal sympathetic nerve activity (RSNA) in response to graded hypoxia before and after intravenous administration of Ang II (20 ng/kg/min, i.v. 30 min) or AT1(More)
The purpose of this study was to determine if the renal sympathetic nerve discharge (RSND), mediated by the paraventricular nucleus of the hypothalamus (PVN), is altered in streptozotocin (STZ) induced diabetic rats. Two to three weeks prior to the start of the experiment the diabetic group was treated with a single injection of STZ (65 mg/kg ip) in a 2%(More)
We sought to identify the areas that have altered neuronal activity within the hypothalamus of rats with heart failure (HF) by mapping neuronal staining of c-Fos protein (Fos) 6-8 weeks following coronary artery ligation (HF group; n=17) or sham surgery (sham-operated control group, n=15). Fos-like immunoreactivity was observed in the paraventricular(More)
We hypothesized that gene transfer of neuronal nitric oxide synthase (nNOS) into the rostral ventrolateral medulla (RVLM) improves baroreflex function in rats with chronic heart failure (CHF). Six to eight weeks after coronary artery ligation, rats showed hemodynamic signs of CHF. A recombinant adenovirus, either Ad.nNOS or Ad.beta-Gal, was transfected into(More)
One characteristic of heart failure (HF) is increased sympathetic activation. The paraventricular nucleus (PVN) of the hypothalamus (involved in control of sympathetic outflow) has been shown to have increased neuronal activation during HF. This study examined the influence of endogenous GABA input (inhibitory in nature) into the PVN on renal sympathetic(More)
1. A number of neurohumoral processes are activated in heart failure (HF), including an increase in the plasma concentration of noradrenaline. 2. Few studies have been performed to examine the role of the central nervous system (CNS) in the activation of sympathetic outflow during HF. In the present paper we review the limited studies performed to examine(More)