The effects of hypoxia on catecholamine dynamics in the rat carotid body
James J. Brokaw, John T. Hansen, Douglas S. Christie
The catecholamine content of the rat carotid body was assayed using high performance liquid chromatography with electrochemical detection. The concentration of dopamine (DA) was found to predominate over that of norepinephrine (NE) by a small margin (31 pmol/carotid body pair DA; 23 pmol/carotid body pair NE). The turnover rates of carotid body DA and NE were determined from the time-dependent decline in their concentrations following the blockade of synthesis with α-methyl-p-tyrosine. Values were obtained (DA t 1 2 = 1.9 h; NE t 1 2 = 2.3 h) which suggested a rapid turnover of carotid body catecholamines. Exposure of rats to conditions of severe hypoxia (5% O2-95% N2) failed to significantly alter either the content or turnover of carotid body catecholamines. By contrast, the concentration of carotid body DOPAC, a reflection of DA utilization, was significantly elevated following hypoxic conditions. Further, in vivo tyrosine hydroxylase activity was assessed by measuring the accumulation of carotid body DOPA after inhibiting l-aromatic amino acid decarboxylase with NSD-1015. Basal tyrosine hydroxylase activity (∼ 14-16 pmol/carotid body pair/h) also was significantly increased by acute hypoxic exposure. These results, in part, suggest that rat carotid body DA may act as a neurotransmitter whose synthesis and release are coupled to stimulus demand.
Journal of the Autonomic Nervous System
Carotid Body
Aromatic-L-Amino-Acid Decarboxylases
High Pressure Liquid Chromatography
tyrosine hydroxylase activity
Brokaw, J. J., Hansen, J. T., & Christie, D. S. (1985). The effects of hypoxia on catecholamine dynamics in the rat carotid body. Journal of the Autonomic Nervous System, 13(1), 35-47. https://doi.org/10.1016/0165-1838(85)90004-9
The effects of hypoxia on catecholamine dynamics in the rat carotid body. / Brokaw, James J.; Hansen, John T.; Christie, Douglas S.
In: Journal of the Autonomic Nervous System, Vol. 13, No. 1, 1985, p. 35-47.
Brokaw, JJ, Hansen, JT & Christie, DS 1985, 'The effects of hypoxia on catecholamine dynamics in the rat carotid body', Journal of the Autonomic Nervous System, vol. 13, no. 1, pp. 35-47. https://doi.org/10.1016/0165-1838(85)90004-9
Brokaw JJ, Hansen JT, Christie DS. The effects of hypoxia on catecholamine dynamics in the rat carotid body. Journal of the Autonomic Nervous System. 1985;13(1):35-47. https://doi.org/10.1016/0165-1838(85)90004-9
Brokaw, James J. ; Hansen, John T. ; Christie, Douglas S. / The effects of hypoxia on catecholamine dynamics in the rat carotid body. In: Journal of the Autonomic Nervous System. 1985 ; Vol. 13, No. 1. pp. 35-47.
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title = "The effects of hypoxia on catecholamine dynamics in the rat carotid body",
abstract = "The catecholamine content of the rat carotid body was assayed using high performance liquid chromatography with electrochemical detection. The concentration of dopamine (DA) was found to predominate over that of norepinephrine (NE) by a small margin (31 pmol/carotid body pair DA; 23 pmol/carotid body pair NE). The turnover rates of carotid body DA and NE were determined from the time-dependent decline in their concentrations following the blockade of synthesis with α-methyl-p-tyrosine. Values were obtained (DA t 1 2 = 1.9 h; NE t 1 2 = 2.3 h) which suggested a rapid turnover of carotid body catecholamines. Exposure of rats to conditions of severe hypoxia (5{\%} O2-95{\%} N2) failed to significantly alter either the content or turnover of carotid body catecholamines. By contrast, the concentration of carotid body DOPAC, a reflection of DA utilization, was significantly elevated following hypoxic conditions. Further, in vivo tyrosine hydroxylase activity was assessed by measuring the accumulation of carotid body DOPA after inhibiting l-aromatic amino acid decarboxylase with NSD-1015. Basal tyrosine hydroxylase activity (∼ 14-16 pmol/carotid body pair/h) also was significantly increased by acute hypoxic exposure. These results, in part, suggest that rat carotid body DA may act as a neurotransmitter whose synthesis and release are coupled to stimulus demand.",
keywords = "carotid body, catecholamines, hypoxia, metabolism, turnover, tyrosine hydroxylase activity",
author = "Brokaw, {James J.} and Hansen, {John T.} and Christie, {Douglas S.}",
journal = "Autonomic Neuroscience: Basic and Clinical",
T1 - The effects of hypoxia on catecholamine dynamics in the rat carotid body
AU - Brokaw, James J.
AU - Hansen, John T.
AU - Christie, Douglas S.
N2 - The catecholamine content of the rat carotid body was assayed using high performance liquid chromatography with electrochemical detection. The concentration of dopamine (DA) was found to predominate over that of norepinephrine (NE) by a small margin (31 pmol/carotid body pair DA; 23 pmol/carotid body pair NE). The turnover rates of carotid body DA and NE were determined from the time-dependent decline in their concentrations following the blockade of synthesis with α-methyl-p-tyrosine. Values were obtained (DA t 1 2 = 1.9 h; NE t 1 2 = 2.3 h) which suggested a rapid turnover of carotid body catecholamines. Exposure of rats to conditions of severe hypoxia (5% O2-95% N2) failed to significantly alter either the content or turnover of carotid body catecholamines. By contrast, the concentration of carotid body DOPAC, a reflection of DA utilization, was significantly elevated following hypoxic conditions. Further, in vivo tyrosine hydroxylase activity was assessed by measuring the accumulation of carotid body DOPA after inhibiting l-aromatic amino acid decarboxylase with NSD-1015. Basal tyrosine hydroxylase activity (∼ 14-16 pmol/carotid body pair/h) also was significantly increased by acute hypoxic exposure. These results, in part, suggest that rat carotid body DA may act as a neurotransmitter whose synthesis and release are coupled to stimulus demand.
AB - The catecholamine content of the rat carotid body was assayed using high performance liquid chromatography with electrochemical detection. The concentration of dopamine (DA) was found to predominate over that of norepinephrine (NE) by a small margin (31 pmol/carotid body pair DA; 23 pmol/carotid body pair NE). The turnover rates of carotid body DA and NE were determined from the time-dependent decline in their concentrations following the blockade of synthesis with α-methyl-p-tyrosine. Values were obtained (DA t 1 2 = 1.9 h; NE t 1 2 = 2.3 h) which suggested a rapid turnover of carotid body catecholamines. Exposure of rats to conditions of severe hypoxia (5% O2-95% N2) failed to significantly alter either the content or turnover of carotid body catecholamines. By contrast, the concentration of carotid body DOPAC, a reflection of DA utilization, was significantly elevated following hypoxic conditions. Further, in vivo tyrosine hydroxylase activity was assessed by measuring the accumulation of carotid body DOPA after inhibiting l-aromatic amino acid decarboxylase with NSD-1015. Basal tyrosine hydroxylase activity (∼ 14-16 pmol/carotid body pair/h) also was significantly increased by acute hypoxic exposure. These results, in part, suggest that rat carotid body DA may act as a neurotransmitter whose synthesis and release are coupled to stimulus demand.
KW - carotid body
KW - catecholamines
KW - hypoxia
KW - metabolism
KW - turnover
KW - tyrosine hydroxylase activity
JO - Autonomic Neuroscience: Basic and Clinical
JF - Autonomic Neuroscience: Basic and Clinical