title: Effect of Caffeine Chronically Consumed During Pregnancy on Adenosine A1and A2AReceptors Signaling in Both Maternal and Fetal Heart from Wistar Rats.
abstract: Background:Caffeine is the most widely consumed psychoactive substance in the world, even during pregnancy. Its stimulatory effects are mainly due to antagonism of adenosine actions by blocking adenosine A1and A2Areceptors. Previous studies have shown that caffeine can cross the placenta and therefore modulate these receptors not only in the fetal brain but also in the heart.Methods:In the present work, the effect of caffeine chronically consumed during pregnancy on A1and A2Areceptors in Wistar rat heart, from both mothers and their fetuses, were studied using radioligand binding, Western-blotting, and adenylyl cyclase activity assays, as well as reverse transcription polymerase chain reaction.Results:Caffeine did not significantly alter A1R neither at protein nor at gene expression level in both the maternal and fetal heart. On the contrary, A2AR significantly decreased in the maternal heart, although mRNA was not affected. Gi and Gs proteins were also preserved. Finally, A1R-mediated inhibition of adenylyl cyclase activity did not change in the maternal heart, but A2AR mediated stimulation of this enzymatic activity significantly decreased according to the detected loss of this receptor.Conclusions:Opposite to the downregulation and desensitization of the A1R/AC pathway previously reported in the brain, these results show that this pathway is not affected in rat heart after caffeine exposure during pregnancy. In addition, A2AR is downregulated and desensitized in the maternal heart, suggesting a differential modulation of these receptor-mediated pathways by caffeine.
authors.affiliation: Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha , Ciudad Real, Spain .
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Iglesias
authors.affiliation: Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha , Ciudad Real, Spain . ; Facultad de Medicina de Ciudad Real; Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla-La Mancha , Ciudad Real, Spain .
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Albasanz
authors.affiliation: Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha , Ciudad Real, Spain . ; Facultad de Medicina de Ciudad Real; Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla-La Mancha , Ciudad Real, Spain .
authors.forename: Mairena
authors.initials: M
authors.lastname: Martín