G protein-coupled receptor kinases: gotta real kure for heart failure?
- S F Steinberg
- Journal of the American College of Cardiology
The effects of alterations in calcium in the perfusion media were studied on b-adrenergic coupling in isolated hearts from 3 different transgenic mice: cardiac-specific overexpressed a1 subunit of L-type calcium channel, overexpressed Gaq, and phospholamban knockout. Isolated hearts from all 3 models, when studied at [Ca] of 2 mmol/L in the perfusate, showed the usual blunted or no response to b-adrenergic stimulation. Lowering [Ca] to 0.75 to 1.5 mmol/L unloaded the hearts of calcium and restored to nearly normal the responsiveness to b-agonist stimulation.