“…It has been shown that ET-1, angiotensin II (AT 1 -receptor stimulation), and phenylephrine (α 1 -adrenoceptor stimulation) share the common signaling pathway coupled to heterotrimeric G q proteins resulting in activation of PKC and MLCK in the heart (10,15,16). Namely, activation of G q proteins leads to generation of DAG that stimulates PKC activity to lead to phosphorylation of both troponin I (13,23,24) and MLC-2 (13,23) in cardiac myocytes.…”