GRK2 and hydrops fetalis: The unaltered PKA-dependent phosphorylation of PLN was associated with an increase in protein phosphatase 1 (PP1; to 159 ± 31%; P < 0.05; Fig. 6D.i), protein phosphatase 2a (PP2a, to 198 ± 38%; P < 0.01; Fig. 6D.ii) and G-protein receptor kinase 2 (GRK-2; to 161 ± 32%; P < 0.05; Fig. 6E) expression HF.