Yoshitaka Hirooka

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1. This paper reviews studies carried out in our laboratory in which we have used the c-fos functional mapping method, in combination with other methods, to determine the functional organization of central baroreceptor pathways as they operate in the conscious rabbit. 2. First, we showed that periods of induced hypertension or hypotension each result in a(More)
Nitric oxide (NO) and reactive oxygen species (ROS) play important roles in blood pressure regulation via the modulation of the autonomic nervous system, particularly in the central nervous system (CNS). In general, accumulating evidence suggests that NO inhibits, but ROS activates, the sympathetic nervous system. NO and ROS, however, interact with each(More)
The pressor region in the rostral part of the ventrolateral medulla (VLM) in the rabbit contains a high density of the AT1 subtype of angiotensin (Ang) II receptor. In this study in anaesthetized barodenervated rabbits, we determined the effect of microinjection into the rostral VLM of the AT1 receptor antagonist losartan and the AT2 receptor antagonist(More)
The involvement of reactive oxygen species such as superoxide is implicated in the pathogenesis of hypertension. The brain contains a high concentration of polyunsaturated fatty acids in its cell membranes. These fatty acids are targets of oxygen-derived free radicals. Thiobarbituric acid-reactive substances (TBARS), an indirect marker of oxidative stress,(More)
BACKGROUND Oxidative stress increases in hypertension. The aim of this study was to determine whether reactive oxygen species (ROS) are increased in the rostral ventrolateral medulla (RVLM) in the brainstem, where the vasomotor center is located, in stroke-prone spontaneously hypertensive rats (SHRSP), and, if so, to determine whether the increased ROS(More)
The information about the effect of mental activities on detailed cardiovascular responses is limited, though strong and chronic psychological stressors are risk factors of cardiovascular morbidity and mortality in humans. The responses of vascular resistance (VR) during fear-induced stress was studied by measuring the mean arterial pressure (MAP), heart(More)
OBJECTIVES Neuregulin-1 (NRG-1), located in the central nervous system (CNS), plays an important role in synaptic function, neurite outgrowth, and survival of neurons and glia acting on the ErbB receptor family. However, the functional role of NRG-1/ErbB signaling in the CNS and blood pressure regulation is unknown, particularly in the rostral ventrolateral(More)
Activation of the sympathetic nervous system has an important role in the pathogenesis of hypertension. However, the precise mechanisms involved are not fully understood. Oxidative stress may be important in hypertension as well as in other cardiovascular disorders. We investigated the role of oxidative stress, particularly in the rostral ventrolateral(More)
Rho-kinase is a signaling molecule that occurs downstream of the small GTPase Rho, which mediates various cellular functions. The Rho/Rho-kinase pathway plays an important role in pathophysiology and progression of various cardiovascular diseases such as hypertension, coronary vasospasm, angina pectoris, and restenosis after percutaneous coronary(More)
Recent studies have demonstrated that the Rho/Rho-kinase pathway plays an important role in various cellular functions, including actin cytoskeleton organization and vascular smooth muscle contraction. This pathway is also present in the central nervous system and is involved in the maintenance of dendritic spines and axon outgrowth and in the regulation of(More)