Interactions between an alpha2-adrenergic antagonist and a beta3-adrenergic agonist on the expression of XXXX and @entity5485 in rats.

@entity3160 @entity47322 @entity5484 @entity5485
This experimental trial was devised to assess whether selective beta3-adrenergic receptor (AR) stimulation and simultaneous blockade of alpha2-AR would affect thermoregulation. With this purpose, the individual and combined administration of a beta-AR agonist, @entity47322 , and an alpha2-AR antagonist, @entity3160 , were evaluated. @entity3160 produced a marked decrease (p < 0.001) in body temperature one hour after administration (5 mg kg(-1), i.p.) and blocked the thermogenic effect of @entity47322 (1 mg kg(-1), i.p.) when simultaneously administered. Uncoupling protein-2 expression in skeletal muscle was downregulated (p < 0.05) by @entity47322 , while @entity3160 had no effect. White adipose tissue @entity5484 and muscle @entity5485 were not modified by either @entity47322 or @entity3160 administration. Liver @entity5484 mRNA expression was significantly decreased by @entity3160 (p < 0.05). However, this downregulation does not seem to explain the reduction in temperature produced by @entity3160 given the fact that @entity47322 produced a similar downregulation of hepatic @entity5484 (p < 0.05). The present work indicates that alpha2-AR antagonism blocks the thermogenic effects mediated by beta3-AR stimulation, contrary to our expectations, suggesting a possible interplay between both mechanisms. Moreover, these effects are not apparently explained by changes in @entity5484 and @entity5485 .
