Adenylyl cyclase and G protein receptor kinase expression during development of heart failure

We examined alterations in left ventricular (LV) G protein receptor kinase (GRK) and adenylyl cyclase (AC) isoform expression during the development of pacing-induced congestive heart failure (CHF). AC isoform and GRK expression were assessed 4 (mild CHF) and 28 (severe CHF) days after initiation of pacing. LV beta-adrenergic receptor (beta-AR) number and G protein content were unchanged by mild CHF. LV AC isoform mRNA content was unaltered by mild CHF, but there were increases in total GRK activity (P