%0 Journal Article %1 Foerster2004 %A Foerster, K. %A Kaeferstein, T. %A Groner, F. %A Engelhardt, S. %A Matthes, J. %A Koch, W. J. %A Lohse, M. J. %A Herzig, S. %D 2004 %J Naunyn Schmiedebergs Arch Pharmacol %K Adrenergic Animals Blockers/metabolism Calcium Cardiac Channel Channels/drug Isoproterenol/*pharmacology Isradipine/metabolism Mice Myocytes, Transgenic beta-1/drug beta-2/drug beta-Agonists/*pharmacology effects/*physiology Receptor %N 5 %P 490-5 %T Calcium channel function and regulation in beta 1- and beta 2-adrenoceptor transgenic mice %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15083268 %V 369 %X Cardiac effects of catecholamines on the L-type calcium channel depend on beta-adrenoceptor subtype (beta(1)- vs. beta(2)-adrenoceptor). Chronic overexpression of these receptors leads to hypertrophy and early death at moderate (beta(1)) or excessive (beta(2)) levels of overexpression respectively. In order to examine the role of L-type calcium channels in altered cardiomyocyte calcium homeostasis found with beta(1)-adrenoceptor overexpression, and to understand the quantitative differences between beta-adrenoceptor subtypes regarding calcium channel regulation, we examined single channels in myocytes obtained from beta(1)- and beta(2)-adrenoceptor transgenic mice. The effects of the agonist isoproterenol were investigated and compared with acute receptor stimulation in the respective non-transgenic littermates. Channels from beta(1)-adrenoceptor transgenic mice have normal baseline activity, and channel number is not reduced. This contrasts to previous findings with beta(2)-adrenoceptor transgenic mice, where channel activity is depressed. Isoproterenol is unable to stimulate channel activity in both transgenic models. In conclusion, the L-type calcium channel is not likely to be involved in alterations of calcium handling of beta(1)-adrenoceptor transgenic myocytes. Furthermore, chronic beta(1)-adrenoceptor overexpression does not depress channel activity, giving another example of the difference between beta(1)- and beta(2)-adrenoceptor signal transduction.

@article{Foerster2004, abstract = {Cardiac effects of catecholamines on the L-type calcium channel depend on beta-adrenoceptor subtype (beta(1)- vs. beta(2)-adrenoceptor). Chronic overexpression of these receptors leads to hypertrophy and early death at moderate (beta(1)) or excessive (beta(2)) levels of overexpression respectively. In order to examine the role of L-type calcium channels in altered cardiomyocyte calcium homeostasis found with beta(1)-adrenoceptor overexpression, and to understand the quantitative differences between beta-adrenoceptor subtypes regarding calcium channel regulation, we examined single channels in myocytes obtained from beta(1)- and beta(2)-adrenoceptor transgenic mice. The effects of the agonist isoproterenol were investigated and compared with acute receptor stimulation in the respective non-transgenic littermates. Channels from beta(1)-adrenoceptor transgenic mice have normal baseline activity, and channel number is not reduced. This contrasts to previous findings with beta(2)-adrenoceptor transgenic mice, where channel activity is depressed. Isoproterenol is unable to stimulate channel activity in both transgenic models. In conclusion, the L-type calcium channel is not likely to be involved in alterations of calcium handling of beta(1)-adrenoceptor transgenic myocytes. Furthermore, chronic beta(1)-adrenoceptor overexpression does not depress channel activity, giving another example of the difference between beta(1)- and beta(2)-adrenoceptor signal transduction.}, added-at = {2010-12-14T18:12:02.000+0100}, author = {Foerster, K. and Kaeferstein, T. and Groner, F. and Engelhardt, S. and Matthes, J. and Koch, W. J. and Lohse, M. J. and Herzig, S.}, biburl = {https://www.bibsonomy.org/bibtex/2bdb6eba39d600a77aecb1fcdde54e189/pharmawuerz}, endnotereftype = {Journal Article}, interhash = {73518939175d6f94d23364982c76d14d}, intrahash = {bdb6eba39d600a77aecb1fcdde54e189}, issn = {0028-1298 (Print) 0028-1298 (Linking)}, journal = {Naunyn Schmiedebergs Arch Pharmacol}, keywords = {Adrenergic Animals Blockers/metabolism Calcium Cardiac Channel Channels/drug Isoproterenol/*pharmacology Isradipine/metabolism Mice Myocytes, Transgenic beta-1/drug beta-2/drug beta-Agonists/*pharmacology effects/*physiology Receptor}, month = May, note = {Foerster, Katharina Kaeferstein, Tomas Groner, Ferdi Engelhardt, Stefan Matthes, Jan Koch, Walter J Lohse, Martin J Herzig, Stefan Research Support, Non-U.S. Gov't Germany Naunyn-Schmiedeberg's archives of pharmacology Naunyn Schmiedebergs Arch Pharmacol. 2004 May;369(5):490-5. Epub 2004 Apr 9.}, number = 5, pages = {490-5}, shorttitle = {Calcium channel function and regulation in beta 1- and beta 2-adrenoceptor transgenic mice}, timestamp = {2010-12-14T18:22:39.000+0100}, title = {Calcium channel function and regulation in beta 1- and beta 2-adrenoceptor transgenic mice}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15083268}, volume = 369, year = 2004 }