Iontophoresis of 6-hydroxydopamine (6-HD) to the rabbit eye, followed by topical instillation of 2% epinephrine, induces ocular shedding of herpes simplex virus type 1 (HSV-1) reliably and with a high frequency in latently infected rabbits. Rabbit eyes inoculated with HSV-1 (McKrae strain) showed dendritic lesions indicative of acute HSV infection and subsequently shed virus spontaneously at least once during days 20 to 39 postinoculation (P.I.). Two iontophoretic conditions were employed. Group A (3 rabbits, 60.3 days P.I.) received iontophoresis of 1.0% 6-HD at 0.75 mAmp for 3 min. Group B (three rabbits, 67.3 days P.I.) received iontophoresis of 0.1% 6-HD at 0.5 mAmp for 8 min. Following iontophoresis, 2% epinephrine was instilled topically once on the day of iontophoresis and twice daily for four consecutive days. Tear film was collected on Dacron swabs and titered on African green monkey kidney cells by a plaque assay procedure. In group A, 100% (6/6) of the eyes shed virus, and the average duration of shedding was 4.0 days. The titers ranged from 2.0 to 7.7×104plaque-forming units (PFU) per eve. The highest daily average titer, 9.89×103PFU/eye, occurred on day 5 following iontophoresis. In Group B, 100% (6/6) of the eyes also shed virus, and the average duration of shedding was 5.3 days. The viral titer of the tear film ranged from 5.0 to 1.4×105PFU/eye. The highest daily average titer, 4.68×103PFU/eye, also occurred on day 5 following iontophoresis. There were no statistically significant differences in the kinetic and quantitative results of HSV-1 shedding between the two iontophoretic conditions. This is thefirstreport of thequantitationof HSV-1 in the tear film after iontophoresis of 6-HD is used to super-sensitize the eyes to adrenergic agents, followed by topical application of 2% epinephrine to induce viral shedding.