If a database is participating in replication, particular care needs to be taken if you want to unload and reload the databases.
For instructions for unloading and reloading databases involved in SQL Remote replication, see Upgrading SQL Remote.
Replication is based on the transaction log. When a database is unloaded and reloaded, the old transaction log is no longer available. For this reason, good backup practices are especially important when participating in replication.
For the steps involved in unloading a databases involved in replication, see Rebuilding databases involved in synchronization or replication.