| Literature DB >> 10087338 |
J Gao1, R Wymore, R T Wymore, Y Wang, D McKinnon, J E Dixon, R T Mathias, I S Cohen, G J Baldo.
Abstract
1. Guinea-pig ventricle was used in the RNase protection assays to determine which alpha-isoforms of the Na+-K+ pumps are present, and ventricular myocytes were used in whole cell patch clamp studies to investigate the actions of alpha- and beta-adrenergic agonists on Na+-K+ pump current. 2. RNase protection assays showed that two isoforms of the alpha-subunit of the Na+-K+-ATPase are present in guinea-pig ventricle. The mRNA for the alpha1-isoform comprises 82 % of the total pump message, the rest being the alpha2-isoform. 3. We have previously shown that beta-adrenergic agonists affect Na+-K+ pump current (Ip) through a protein kinase A (PKA)-dependent pathway. We now show that these beta-effects are targeted to the alpha1-isoform of the Na+-K+ pumps. 4. We have also previously shown that alpha-adrenergic agonists increase Ip through a protein kinase C (PKC)-dependent pathway. We now show that these alpha-isoform effects are targeted to the alpha2-isoform of the Na+-K+ pumps. 5. These results suggest the effects of adrenergic activation on Na+-K+ pump activity in the heart can be regionally specific, depending on which alpha-isoform of the Na+-K+ pump is expressed.Entities:
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Year: 1999 PMID： 10087338 PMCID： PMC2269277 DOI： 10.1111/j.1469-7793.1999.0377v.x
Source DB: PubMed Journal: J Physiol ISSN： 0022-3751 Impact factor: 5.182