Phosphorylation of phospholemman (PLM) on ser68 has been proposed to at least partially mediate cyclic AMP (cAMP) mediated relaxation of arterial smooth muscle. We evaluated the time course of the phosphorylation of phospholemman (PLM) on ser68, myosin regulatory light chains (MRLC) on ser19, and heat shock protein 20 (HSP20) on ser16 during a transient forskolininduced relaxation of histamine-stimulated swine carotid artery. We also evaluated the dose response for forskolin- and nitroglycerin-induced relaxation in phenylephrine-stimulated PLM-/- and PLM+/+ mice. The time course for changes in ser19 MRLC dephosphorylation and ser16 HSP20 phosphorylation was appropriate to explain the forskolin-induced relaxation and the recontraction observed upon washout of forskolin. However, the time course for changes in ser68 PLM phosphorylation was too slow to explain forskolin-induced changes in force. There was no difference in the phenylephrine contractile dose response or in forskolin-induced relaxation dose response observed in PLM-/- and PLM+/+ aortae. In aortae precontracted with phenylephrine, nitroglycerin induced a slightly, but significantly greater relaxation in PLM-/- compared to PLM+/+ aortae. These data are consistent with the hypothesis that ser19 MRLC dephosphorylation and ser16 HSP20 phosphorylation are involved in forskolininduced relaxation. Our data suggest that PLM phosphorylation is not significantly involved in forskolin-induced arterial relaxation.

• Klíčová slova
• Cyclic AMP, FXYD protein, HSP20, Myosin light chain, Vascular smooth muscle,
• MeSH
• AMP cyklický metabolismus   MeSH
• aorta metabolismus   účinky léků   MeSH
• arteriae carotides metabolismus   účinky léků   MeSH
• časové faktory MeSH
• fosfoproteiny genetika   metabolismus   nedostatek   MeSH
• fosforylace MeSH
• kolforsin farmakologie   MeSH
• lehké řetězce myosinu metabolismus   MeSH
• membránové proteiny genetika   metabolismus   nedostatek   MeSH
• myši knockoutované MeSH
• myši MeSH
• nitroglycerin farmakologie   MeSH
• prasata MeSH
• proteiny tepelného šoku HSP20 metabolismus   MeSH
• vazodilatace účinky léků   MeSH
• vazodilatancia farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH