Browsing by Author "Beneš, Jan"
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- ItemBeta3 adrenoceptors substitute the role of M 2 muscarinic receptor in coping with cold stress in the heart: Evidence from M 2KO mice(Technická Univerzita v Liberci, 2012) Beneš, Jan; Nováková, Martina; Rotková, Jana; Farár, Vladimír; Květňanský, Richard; Riljak, V.; Mysliveček, Jaromír B.We investigated the role of beta3-adrenoceptors (AR) in cold stress (1 or 7 days in cold) in animals lacking main cardioinhibitive receptors - M2 muscarinic receptors (M 2KO). There was no change in receptor number in the right ventricles. In the left ventricles, there was decrease in binding to all cardiostimulative receptors (beta1-, and beta2-AR) and increase in cardiodepressive receptors (beta3-AR) in unstressed KO in comparison to WT. The cold stress in WT animals resulted in decrease in binding to beta1- and beta2-AR (to 37%/35% after 1 day in cold and to 27%/28% after 7 days in cold) while beta3-AR were increased (to 216% of control) when 7 days cold was applied. MR were reduced to 46% and 58%, respectively. Gene expression of M2 MR in WT was not changed due to stress, while M3 was changed. The reaction of beta1- and beta2-AR (binding) to cold was similar in KO and WT animals, and beta3-AR in stressed KO animals did not change. Adenylyl cyclase activity was affected by beta3-agonist CL316243 in cold stressed WT animals but CL316243 had almost no effects on adenylyl cyclase activity in stressed KO. Nitric oxide activity (NOS) was not affected by BRL37344 (beta3-agonist) both in WT and KO animals. Similarly, the stress had no effects on NOS activity in WT animals and in KO animals. We conclude that the function of M2 MR is substituted by beta3-AR and that these effects are mediated via adenylyl cyclase rather than NOS. © Springer Science+Business Media, LLC 2011.
- ItemThe restructuring of dopamine receptor subtype gene transcripts in c-fos KO mice(Pergamon-Elsevier Science Ltd, 2012) Beneš, Jan; Mravec, Boris; Križanova, Oľga; Květňanský, Richard; Mysliveček, Jaromír B.Although c-Fos protein is one of the principal molecules in intracellular signaling, c-fos gene disruption is associated with alterations in neuronal functions that do not correspond to its importance in function. The aim of the study was to evaluate the changes of dopaminergic system together with acetylcholinesterase (AChE) in c-fos disruption (KO). KO male mice showed an increase in D 1-like receptor (279% of WT) and D 2-like receptor (345% of WT) binding sites in the cortex. On the gene expression level (assessed by real-time PCR), lower quantities of D 1R-mRNA (0.64) and D 5R-mRNA (0.6) were found in females when compared to males in the frontal cortex, higher D 2R-mRNA in the parietal (1.43) and temporal (2.64) cortex and lower AChE-mRNA (0.67). On the contrary, female striatum contained higher level of D 2R-mRNA (1.62) and AChE-mRNA (1.57) but lower level of D 3R-mRNA (0.73). Hypothalamic D 1R-mRNA, D 2R-mRNA and D 4R-mRNA were higher in females (1.38, 1.63, and 1.68, respectively). Disruption of c-fos increased selectively D 5R-mRNA (1.31) in male parietal cortex, D 2R-mRNA (1.72) in male temporal cortex, and cerebellar D 2R-mRNA in both males (1.43) and females (1.42), respectively. In females, we found rather decrease in DR-mRNA. Multiple correlations in mRNA quantities (in WT mice) were found, which changed considerably upon c-fos KO. Main interactions in WT were inter-regional, CNS of KO underwent an extensive restructuring comprising intraregional interactions in the frontal cortex, hypothalamus, and cerebellum. These changes in DR (between others) could be considered as one of the adaptive mechanisms in c-fos KO mice. © 2012 Elsevier Inc.