Biological behaviour of 6-chloro-2',3'-dideoxyguanosine and 6-chloro-2',3'-dideoxyinosine in the brains of mice.

By using tissue and blood from mice and mice themselves, biological behavior of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) and 6-chloro-2',3'-dideoxyinosine (6-Cl-ddI) was examined in vitro and in vivo. Both compounds resemble each other in chemical structure. They are converted to ddG and ddI, respectively, by adenosine deaminase in the cells, and express their anti-HIV activity in vitro. According to our recent data about their biological behaviour in vivo; however, it was revealed that they are fairly different especially as the agent working in the brain. After injection of each drug into the body of mice, ddG, or metabolite of 6-Cl-ddG, was observed in the brain, while ddI was not found there.