Functional Analysis of Tissue Renin-Angiotensin System Using “Gain and Loss of Function” Approaches: In Vivo Test of in Vitro Hypothesis

The study of the effect of autocrine-paracrine vasoactive modulators (e.g., renin-angiotensin) on VSMC biology is very difficult in vivo because in vivo studies are limited. Recent progress in in vivo gene transfer technologies have provided us with the opportunity to study cellular responses to the manipulation of the individual components (i.e., by overexpression or inhibition). Currently, many researchers have developed many in vivo gene transfer techniques for cardiovascular application, including viral gene transfer and liposomal gene transfer. By using in vivo gene transfer approaches, the roles of the tissue renin-angiotensin system have been identified. Such an approach may increase our understanding of the biology and pathobiology of autocrine-paracrine system. This review has discussed the potential utility of in vivo gene transfer methods.