1A. (Used with permission from the American Journal of Physiology, Kanika et al. 9) Basal intacorporal pressure/blood pressure (ICP/BP) ratio one week after injection of 100 µg of plasmid (pVAX, pVAX-Vcsa1, pVAX-hSMR3B or pVAX-hSlo). The bar represents the mean basal ICP/BP from 5 animals in each group, and the error bars the standard error of the mean (SEM). * = significantly different basal ICP/BP from negative control, pVAX (Students t-test, P<0.05). 1B. Representative sections through the corpora cavernosum of rat tissue, stained with hematoxylin and eosin (HE stain). Left panel, animals treated with 100 µg pVAX (control), middle panel 100 µg pVAX-Vcsa1 and right panel 100 µg pVAX-hSMR3B. Sections of each panel are enlarged, and the presence of blood cells within the vascular spaces enhanced to demonstrate vasocongestion.