Recombinant adenoviruses are attractive vectors for renal gene transfer since they can efficiently transduce nondividing cells. However, despite the fact that renal glomeruli are easily accessible via the renal circulation, attempts to deliver foreign genes specifically into renal glomeruli, using adenoviral vectors, have had limited success in rodents. A simple intraarterial injection of adenoviral vectors into the renal circulation or incubation of the virus with the kidney for an extended period of time was found to be insufficient for this purpose. In this study, we have established an efficient gene transfer protocol to express foreign genes in rat renal glomerular cells, using adenoviral vectors. We demonstrated, for the first time, that rat glomerular endothelial cells could be efficiently transduced by slowly infusing a recombinant adenovirus (Ad.CBlacZ) into the right renal artery for a period of 15 min. High levels of lacZ expression were achieved in renal glomeruli without causing significant damage to renal glomeruli or other kidney structures. The virus-mediated expression lasted for at least 21 days. These data demonstrate the feasibility of using recombinant adenoviral vectors as a tool with which to study the effect of foreign gene expression on the structure and function of rat renal glomeruli in vivo.