Several authors have studied the dependence of galaxy properties on environment in order to understand which mechanisms operate in the galaxy evolution. Recently, some of them have proposed that intermediate densities could be sites where local environment influences the transition of galaxies onto the red-sequence, as opposed to mechanisms that operate on cluster scales. Based on the evidence that interacting and merging systems are frequent at intermediate densities, we use the SDSS-DR4 data to analyse the role of close galaxy interactions as an environmental process which could contribute to lead evolutionary transformations. We explore the properties of galaxy pairs at different local and global density environments, comparing them with those of isolate galaxies in an unbiased control sample (CS).