[Effect of cyclic nucleotides (cAMP) on experimental HSV-I keratitis]

The authors report an experimental study on the effect of cAMP on HSV-I keratitis. Rabbit corneas developed typical dendritic keratitis on the 3rd day after inoculation of HSV-I. On the 9th day, the cAMP level in plasma significantly decreased from 174.9 +/- 20.2 to 52.1 +/- 18.2 pmol/ml, while the cGMP level increased. The cAMP level in aqueous humour also decreased, with an increase in cGMP level increased. The cAMP level in aqueous humour also decreased, with an increase in cGMP level. cAMP was used subconjunctivally for treatment of HSV-I keratitis. 48 hours after injection, the cAMP level in aqueous humour markedly rose from 11.1 +/- 2.0 to 35.6 +/- 12.9 pmol/ml and 6 days later to 65.0 +/- 30.9 pmol/ml, with concurrent decrease in cGMP level, and the ratio of cAMP/cGMP increased from 1.6 +/- 0.6 to 15.3 +/- 4.6. In the group of treatment by acyclovir, the level of cAMP in aqueous humour increased by 9.5 times after 3 days of treatment, with no remarkable effect on the cGMP level. These results showed that cAMP was equally effective as ACV in treatment of experimental HSV 1 keratitis. The antiviral action of cAMP was discussed and the pharmacological effect of cAMP approached.