TY - JOUR
T1 - The impact of adenosine on the release of acetylcholine, dopamine, and norepinephrine from the cat carotid body
AU - Fitzgerald, Robert S.
AU - Shirahata, MacHiko
AU - Wang, Hay Yan Jack
AU - Balbir, Alexander
AU - Chang, Irene
N1 - Funding Information:
This study was financially supported by awards from the NHLBI: HL 50712 and HL 72293.
Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2004/9/9
Y1 - 2004/9/9
N2 - Exogenously administered adenosine provokes an increase in respiration in both animal models and in man. Administered near the carotid body adenosine increases neural output from the carotid body in rats and cats. Hypoxia has the same effect. Hypoxia also provokes a release of acetylcholine (ACh), dopamine (DA), and norepinephrine (NE) from the carotid body. The present study aimed to determine the effect of exogenous adenosine on the release of ACh, DA, and NE from the carotid bodies of cats. After a recovery period (from surgery) carotid bodies were first incubated for 10 (DA, NE) or 15 (ACh) min in Eppendorf tubes containing 85 μL of a physiological salt solution equilibrated with 40% O2/5% CO2 at 37°C (hyperoxia). At the end of the incubation period the medium was drawn off, and measured for ACh, DA, and NE using HPLC-ECD methods. Next 85 μL of the medium and the tubes were equilibrated with a hypoxic gas mixture (4% O2/5% CO2) and the carotid bodies were incubated for 10 (DA, NE) or 15 (ACh) min, at the end of which the medium was drawn off and measured for ACh, DA, and NE. In the ACh studies there followed a post-hypoxic hyperoxic exposure (40% O2/5% CO2). ACh tubes were then made 100 μM with respect to adenosine, and the hyperoxic, hypoxic, and post-hypoxic hyperoxic challenges were repeated. One of the two DA, NE tubes had the 100 μM adenosine from the start. Adenosine significantly increased the release of ACh, but significantly decreased the hypoxia-induced release of DA. Potential mechanisms for these changes are reviewed.
AB - Exogenously administered adenosine provokes an increase in respiration in both animal models and in man. Administered near the carotid body adenosine increases neural output from the carotid body in rats and cats. Hypoxia has the same effect. Hypoxia also provokes a release of acetylcholine (ACh), dopamine (DA), and norepinephrine (NE) from the carotid body. The present study aimed to determine the effect of exogenous adenosine on the release of ACh, DA, and NE from the carotid bodies of cats. After a recovery period (from surgery) carotid bodies were first incubated for 10 (DA, NE) or 15 (ACh) min in Eppendorf tubes containing 85 μL of a physiological salt solution equilibrated with 40% O2/5% CO2 at 37°C (hyperoxia). At the end of the incubation period the medium was drawn off, and measured for ACh, DA, and NE using HPLC-ECD methods. Next 85 μL of the medium and the tubes were equilibrated with a hypoxic gas mixture (4% O2/5% CO2) and the carotid bodies were incubated for 10 (DA, NE) or 15 (ACh) min, at the end of which the medium was drawn off and measured for ACh, DA, and NE. In the ACh studies there followed a post-hypoxic hyperoxic exposure (40% O2/5% CO2). ACh tubes were then made 100 μM with respect to adenosine, and the hyperoxic, hypoxic, and post-hypoxic hyperoxic challenges were repeated. One of the two DA, NE tubes had the 100 μM adenosine from the start. Adenosine significantly increased the release of ACh, but significantly decreased the hypoxia-induced release of DA. Potential mechanisms for these changes are reviewed.
KW - Acetylcholine
KW - Adenosine
KW - Adenosine receptors
KW - Carotid body
KW - Dopamine
KW - Hypoxia
KW - Norepinephrine
UR - http://www.scopus.com/inward/record.url?scp=4444360393&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4444360393&partnerID=8YFLogxK
U2 - 10.1016/j.neulet.2004.06.019
DO - 10.1016/j.neulet.2004.06.019
M3 - Article
C2 - 15337254
AN - SCOPUS:4444360393
SN - 0304-3940
VL - 367
SP - 304
EP - 308
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 3
ER -