Effect of 9-Tetrahydrocannabinol on Herpes Simplex Virus Type 2 Vaginal Infection in the Guinea Pig

Abstract

The present investigation was undertaken to determine whether .DELTA.9-tetrahydrocannbinol (.DELTA.9-THC) decreases host resistance to herpes simplex virus type 2 vaginal infection in the guinea pig. The guinea pig was selected as the host since it has been shown to express a spectrum of primary herpes genitalis which is similar to that in humans. Animals were administered .DELTA.9-THC or vehicle intraperitoneally on Days 1-4, 8-11, and 15-18. Herpes simplex virus was introduced intravaginally on Day 2. Host resistance to virus infection was assessed by comparing frequncy and severity of lesions, virus shedding, and animal mortalities. Virus-infected animals treated with drug at doses of 4 and 10 mg/kg exhibited significantly greater severity of genital disease during the 30-day period of study when compared to virus-inoculated vehicle controls. A direct relationship was noted between dose of .DELTA.9-THC and cumulative mortalities on Day 14 following primary infection. These results indicate that .DELTA.9-THC decreases host resistance to herpes simplex virus type 2 vaginal infection in the guinea pig.