“…Overall, the 1 -adrenoceptors cause vasoconstriction, relaxation of gastrointestinal smooth muscle, salivary secretion, and hepatic glycogenolysis (Pocock andRichards, 2006, Rang et al, 2007). 1 -Adrenoceptors are mainly coupled to G q/11 -protein with consequent activation of phospholipase C. Phospholipase C promotes the hydrolysis of phosphatidylinositol bisphosphate producing inositol trisphosphate and diacylglycerol (Docherty, 1998, Zhong and Minneman, 1999, García-Sáinz et al, 2000, Guimarães and Moura, 2001, which act as second messengers. Inositol trisphosphate mediates intracellular Ca 2+ release from non mitochondrial pools and, consequently, the activation of other Ca 2+ and calmodulin sensitive pathways such as CaMKII, whilst diacylglycerol activates PKC (Guimarães andMoura, 2001, Westfall andWestfall, 2006).…”