TY - JOUR
T1 - Differential expression of A(2a), A1-adenosine and D2-dopamine receptor genes in rat peripheral arterial chemoreceptors during postnatal development
AU - Gauda, E. B.
AU - Northington, F. J.
AU - Linden, J.
AU - Rosin, D. L.
N1 - Funding Information:
The authors would like to thank Patrice Kerr and Guimei Wu for their excellent technical support. This work was supported by the NIH-NHLBI grant HL03365.
PY - 2000/7/28
Y1 - 2000/7/28
N2 - The sensitivity of peripheral arterial chemoreceptors in the carotid body to hypoxia increases with postnatal maturation. Carotid sinus nerve activity is augmented by adenosine binding to A(2a)-adenosine receptors and attenuated by dopamine binding to D2-dopamine receptors. In this study, we used in situ hybridization histochemistry to determine the change in the levels of mRNA expression for A(2a) and A1-adenosine receptors and D2- dopamine receptors in the rat carotid body. We also investigated the cellular distribution and possible colocalization of these receptor mRNAs and tyrosine hydroxylase (TH) mRNAs during the first 2 weeks of postnatal development. By using immunohistocytochemistry, we detected A(2a)-adenosine receptor protein in the carotid body and petrosal ganglion. We found that A(2a)-adenosine receptor mRNA and protein are expressed in the carotid body in animals at 0, 3, 6 and 14 postnatal days. The level of A(2a)-adenosine receptor mRNA expression significantly decreased by 14 postnatal days (P<0.02 vs. day 0) while D2-dopamine receptor mRNA levels significantly increased by day 3 and remained greater than D2-dopamine receptor mRNA levels at day 0 (P<0.001 all ages vs. day 0). TH mRNA was colocalized in cells in the carotid body with A(2a) adenosine receptor and D2-dopamine receptor mRNAs. A1-adenosine receptor mRNA was not expressed in the carotid body at any of the ages examined. In the petrosal ganglion, A1-adenosine receptor mRNA was abundantly expressed in numerous cells, A(2a)-adenosine receptor mRNA was expressed in a moderate number of cells while D2-dopamine receptor mRNA was seen in a few cells in the rostral petrosal ganglion. In conclusion, using in situ hybridization histochemistry, we have shown that mRNA for both the excitatory, A(2a)-adenosine receptor, and the inhibitory, D2-dopamine receptor, is developmentally regulated in presumably type I cells in the carotid body which may contribute to the maturation of hypoxic chemosensitivity. Furthermore, the presence A1-adenosine receptor mRNAs in cell bodies of the petrosal ganglion suggests that adenosine might also have an inhibitory role in hypoxic chemotransmission. (C) 2000 Elsevier Science B.V.
AB - The sensitivity of peripheral arterial chemoreceptors in the carotid body to hypoxia increases with postnatal maturation. Carotid sinus nerve activity is augmented by adenosine binding to A(2a)-adenosine receptors and attenuated by dopamine binding to D2-dopamine receptors. In this study, we used in situ hybridization histochemistry to determine the change in the levels of mRNA expression for A(2a) and A1-adenosine receptors and D2- dopamine receptors in the rat carotid body. We also investigated the cellular distribution and possible colocalization of these receptor mRNAs and tyrosine hydroxylase (TH) mRNAs during the first 2 weeks of postnatal development. By using immunohistocytochemistry, we detected A(2a)-adenosine receptor protein in the carotid body and petrosal ganglion. We found that A(2a)-adenosine receptor mRNA and protein are expressed in the carotid body in animals at 0, 3, 6 and 14 postnatal days. The level of A(2a)-adenosine receptor mRNA expression significantly decreased by 14 postnatal days (P<0.02 vs. day 0) while D2-dopamine receptor mRNA levels significantly increased by day 3 and remained greater than D2-dopamine receptor mRNA levels at day 0 (P<0.001 all ages vs. day 0). TH mRNA was colocalized in cells in the carotid body with A(2a) adenosine receptor and D2-dopamine receptor mRNAs. A1-adenosine receptor mRNA was not expressed in the carotid body at any of the ages examined. In the petrosal ganglion, A1-adenosine receptor mRNA was abundantly expressed in numerous cells, A(2a)-adenosine receptor mRNA was expressed in a moderate number of cells while D2-dopamine receptor mRNA was seen in a few cells in the rostral petrosal ganglion. In conclusion, using in situ hybridization histochemistry, we have shown that mRNA for both the excitatory, A(2a)-adenosine receptor, and the inhibitory, D2-dopamine receptor, is developmentally regulated in presumably type I cells in the carotid body which may contribute to the maturation of hypoxic chemosensitivity. Furthermore, the presence A1-adenosine receptor mRNAs in cell bodies of the petrosal ganglion suggests that adenosine might also have an inhibitory role in hypoxic chemotransmission. (C) 2000 Elsevier Science B.V.
KW - A(2a)-adenosine receptor
KW - Carotid body
KW - Development
KW - Gene expression
KW - Peripheral arterial chemoreceptors
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U2 - 10.1016/S0006-8993(00)02314-3
DO - 10.1016/S0006-8993(00)02314-3
M3 - Article
C2 - 10924669
AN - SCOPUS:0034725754
SN - 0006-8993
VL - 872
SP - 1
EP - 10
JO - Brain research
JF - Brain research
IS - 1-2
ER -