ABSTRACT
AT 18 and AT 2 receptor (Mukoyama et al., 1993; Sandberg et a/., 1992; Yo hida et a/., 1992; Kakar eta/., 1992; Kambaya hi et al. , 1993). ln other pecie , including human , there i only one form of the AT 1 receptor (Sandberg, 1994 ). Mo t of the known action of Ang II involve the AT 1 receptor that i coupled to Gq. Several signaling y tern are involved in the intracellular event following stimulation of the AT 1 receptor and the e include phospholipa e C-mediated pathway , mitogen-activated protein ldna es, and protein tyro ine pho phorylation (Schmitz and Berk, 1997; Berk and Cor on, 1997; Bottari et al., 1993). The action of the AT 2 receptor and its intracellular signaling pathways are being elucidated. The AT2 receptor a ociate with the Gai protein family and i known to inhlbit mitogen-activated protein ldnase activity and protein pho phata e 2A and timulate potassium channel activity (Huang et al. , 1996; Kang et al., 1994; Zhang and Pratt, 1996; ahmias and Stro berg, 1995). Tran genic mice with a disrupted AT2 receptor have increased blood pre ure and orne alteration in behavior (Icillkj et al. , 1995; Hein et al. , 1995). lntere tingly, cardiac-specific over-expre ion of the AT 2 receptor ignificantly attenuates the pre or re pon e to Ang II through a negative chronotropic action (Masald eta/., 1998).
