Reduced colonic motility has been observed in aged rats with a parallel reduction in acetylcholine (Ach)-induced myosin light chain (MLC₂₀) phosphorylation. MLC₂₀ phosphorylation during smooth muscle contraction is maintained by a coordinated signal transduction cascade requiring both PKC and RhoA. Caveolae are membrane microdomains that permit rapid and efficient coordination of different signal transduction cascades leading to sustained smooth muscle contraction of colon. Here we show that normal physiological contraction can be reinstated in aged colonic smooth muscle cells (CSMC) upon transfection with wild-type caveolin-1 through the activation of both the RhoA/Rho-kinase and PKC pathways. Our data demonstrate that impaired contraction in aging is an outcome of altered membrane translocation of PKC and RhoA with a concomitant reduction in the association of these molecules with the caveolae specific protein, caveolin-1 resulting in a parallel decrease in MYPT and CPI-17 phosphorylation. Decreased MYPT and CPI-17 phosphorylation activates MLCP phosphatase activity resulting in MLC₂₀ dephosphorylation which may be responsible for decreased colonic motility in aged rats. Importantly, transfection of CSMC from aged rats with wild type YFP-Cav-1 cDNA restored translocation of RhoA, PKC and phosphorylation of MYPT, CPI-17 and MLC_20, thereby restoring the contractile response to levels comparable to young adult rats. Thus, we propose that caveolin 1 gene transfer may represent a promising therapeutic treatment to correct the age related decline in colonic smooth muscle motility.