Premium
Effect of chronic gestational treatment with caffeine or theophylline on Group I metabotropic glutamate receptors in maternal and fetal brain
Author(s) -
León D.,
Albasanz J. L.,
Ruíz M. A.,
Iglesias I.,
Martín M.
Publication year - 2005
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2005.03211.x
Subject(s) - metabotropic glutamate receptor , theophylline , caffeine , medicine , endocrinology , fetus , glutamate receptor , receptor , metabotropic glutamate receptor 5 , biology , pharmacology , pregnancy , genetics
Pregnant rats were treated throughout the gestational period with either caffeine or theophylline, and its effect on the metabotropic glutamate receptor (mGluRs) signal transduction pathway was studied in both maternal and fetal brain. In maternal brain, radioligand binding assays showed that chronic treatment with methylxanthines caused a significant decrease in the total number of mGluRs. This decrease was accompanied by an increase in receptor affinity. Immunodetection showed that mGluR 1a and phospholipase C β 1 (PLCβ 1 ) were significantly decreased in response to chronic methylxanthine treatment, whereas αG q/11 was not affected. A loss was also detected of PLC stimulation mediated by (S)‐3,5‐dihydroxyphenylglycine (DHPG), a selective Group I mGluR agonist, suggesting desensitization of the mGluR/PLC pathway. In fetal brain, a loss in total mGluRs was observed in fetuses from mothers treated with caffeine or theophylline, without variation in receptor affinity. A decrease in mGluR 1a , αG q/11 and PLCβ 1 levels was also observed in response to treatment. However, changes detected in this immature tissue were not associated with variations in PLC activity. These results suggest that chronic caffeine or theophylline treatment down‐regulates several mGluR/PLC transduction pathway components in both maternal and fetal brain, causing a loss of receptor responsiveness only in maternal brain.