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Amino acids that centrally influence blood pressure and regional blood flow in conscious rats.

Takemoto Y - J Amino Acids (2012)

Bottom Line: This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow.Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements.Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology, Graduate School Biomedical Sciences, Hiroshima University, Kasumi-cho 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan.

ABSTRACT
Functional roles of amino acids have increasingly become the focus of research. This paper summarizes amino acids that influence cardiovascular system via the brain of conscious rats. This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow. This section includes a concise history of amino acid neurotransmitters in cardiovascular research and summarizes brain areas where chemical stimulations produce blood pressure changes mainly in anesthetized animals. This is followed by comments about findings regarding several newly examined amino acids with intracisternal stimulation in conscious rats that produce changes in blood pressure. The same pressor or depressor response to central amino acid stimulations can be produced by distinct mechanisms at central and peripheral levels, which will be briefly explained. Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements. Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows. They may have physiological roles in the healthy brain, but pathological roles in the brain with cerebral vascular diseases such as stroke where the blood-brain barrier is broken.

No MeSH data available.


Related in: MedlinePlus

Blood pressure is produced by cardiac output and total peripheral resistance.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368589&req=5

fig1: Blood pressure is produced by cardiac output and total peripheral resistance.

Mentions: Blood pressure (specified for arterial blood pressure here) is determined by cardiac output and total peripheral resistance (Figure 1). The heart works spontaneously and propels the blood into the aorta depending on blood volume returned from the vena cava. The brain modifies the cardiac work with cardiac parasympathetic and sympathetic neurons, adrenaline released from the adrenal gland via sympathetic activation, and an increase in venous return with increased sympathetic activity to the capacitance venous vessels. Another variable of peripheral blood flow resistances consists of a lot of acting sites, arterioles all over the body, which are located just before the vascular (capillary) bed of each organ (Figure 2). The brain can modify the size of arterioles with vascular sympathetic neurons and release of several vasoactive factors into the blood stream as mentioned below in detail. For proper delivery of the blood into the demanding organ, regulation of the arterioles could be essential. Vasomotor sympathetic neurons are tonic at rest but regulated by increasing or decreasing activities (Figure 3), resulting in optimal blood flow shift among different vascular beds for demanding organs, in theory.


Amino acids that centrally influence blood pressure and regional blood flow in conscious rats.

Takemoto Y - J Amino Acids (2012)

Blood pressure is produced by cardiac output and total peripheral resistance.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368589&req=5

fig1: Blood pressure is produced by cardiac output and total peripheral resistance.
Mentions: Blood pressure (specified for arterial blood pressure here) is determined by cardiac output and total peripheral resistance (Figure 1). The heart works spontaneously and propels the blood into the aorta depending on blood volume returned from the vena cava. The brain modifies the cardiac work with cardiac parasympathetic and sympathetic neurons, adrenaline released from the adrenal gland via sympathetic activation, and an increase in venous return with increased sympathetic activity to the capacitance venous vessels. Another variable of peripheral blood flow resistances consists of a lot of acting sites, arterioles all over the body, which are located just before the vascular (capillary) bed of each organ (Figure 2). The brain can modify the size of arterioles with vascular sympathetic neurons and release of several vasoactive factors into the blood stream as mentioned below in detail. For proper delivery of the blood into the demanding organ, regulation of the arterioles could be essential. Vasomotor sympathetic neurons are tonic at rest but regulated by increasing or decreasing activities (Figure 3), resulting in optimal blood flow shift among different vascular beds for demanding organs, in theory.

Bottom Line: This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow.Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements.Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurophysiology, Graduate School Biomedical Sciences, Hiroshima University, Kasumi-cho 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan.

ABSTRACT
Functional roles of amino acids have increasingly become the focus of research. This paper summarizes amino acids that influence cardiovascular system via the brain of conscious rats. This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow. This section includes a concise history of amino acid neurotransmitters in cardiovascular research and summarizes brain areas where chemical stimulations produce blood pressure changes mainly in anesthetized animals. This is followed by comments about findings regarding several newly examined amino acids with intracisternal stimulation in conscious rats that produce changes in blood pressure. The same pressor or depressor response to central amino acid stimulations can be produced by distinct mechanisms at central and peripheral levels, which will be briefly explained. Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements. Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows. They may have physiological roles in the healthy brain, but pathological roles in the brain with cerebral vascular diseases such as stroke where the blood-brain barrier is broken.

No MeSH data available.


Related in: MedlinePlus