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Altered expression of adenosine A1 and A2A receptors in the carotid body and nucleus tractus solitarius of adult male and female rats following neonatal caffeine treatment.
- Source :
-
Brain research [Brain Res] 2009 Sep 01; Vol. 1287, pp. 74-83. Date of Electronic Publication: 2009 Jun 26. - Publication Year :
- 2009
-
Abstract
- Neonatal caffeine treatment (adenosine receptor antagonist, 15 mg/kg/day, between postnatal days 3 and 12) affects respiratory patterns in adult male but not female rats as shown by an increase in the respiratory frequency in the early phase of response to hypoxia and an increase in the tidal volume in the late phase of response. Here, we tested the hypothesis that these changes are correlated with modified expression of adenosine receptors in the chemoreflex pathway. Carotid bodies, nucleus tractus solitarii, and superior cervical ganglia were collected from 3-month-old male and female rats that were either naive (not manipulated during the neonatal period) or treated with caffeine (NCT) or water (NWT) between postnatal days 3 and 12 by gavage. Western blot analysis was used to assess the expression of adenosine A(1) and A(2A) receptors and tyrosine hydroxylase, the rate-limiting enzyme for dopamine synthesis. In male rats, there was a 37% increase in the level of A(2A) receptor and a 17% decrease in tyrosine hydroxylase in the carotid body of NCT (p<0.001) as compared to NWT rats. In the nucleus tractus solitarius, we found a 13% and 19% decrease in A(1) receptor expression in NWT and NCT rats (p<0.01), respectively, compared to naive rats. In the superior cervical ganglion, there was no change in A(1) receptor, A(2A) receptor, and tyrosine hydroxylase expression. In female rats, the only changes observed were decreases of 12% and 15% in A(1) receptor levels in the nucleus tractus solitarius of NWT and NCT rats (p<0.01), respectively, compared to naive rats. We conclude that NCT induces long-term changes in the adenosine receptor system. These changes may partially explain the modifications of the respiratory pattern induced by NCT in adults. The increased expression of the adenosine A(2A) receptor (specific to male rats), combined with the decreased tyrosine hydroxylase expression in the carotid body, suggests that NCT affects adenosine-dopamine interactions regulating chemosensory activity.
- Subjects :
- Adenosine A1 Receptor Antagonists
Adenosine A2 Receptor Antagonists
Age Factors
Animals
Animals, Newborn
Caffeine pharmacology
Carotid Body drug effects
Carotid Body enzymology
Female
Gene Expression Regulation, Developmental drug effects
Male
Rats
Rats, Sprague-Dawley
Sex Factors
Solitary Nucleus drug effects
Tyrosine 3-Monooxygenase antagonists & inhibitors
Tyrosine 3-Monooxygenase biosynthesis
Caffeine administration & dosage
Carotid Body metabolism
Gene Expression Regulation, Developmental physiology
Receptor, Adenosine A1 biosynthesis
Receptor, Adenosine A2A biosynthesis
Solitary Nucleus metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1872-6240
- Volume :
- 1287
- Database :
- MEDLINE
- Journal :
- Brain research
- Publication Type :
- Academic Journal
- Accession number :
- 19563784
- Full Text :
- https://doi.org/10.1016/j.brainres.2009.06.064