The film Throne of Blood is actually the story of Macbeth but transported to feudal Japan, and you are right to indicate that the title of this film emphasises the bloody nature of ambition and how blood seems to be an essential part in Macbeth's rise to power. In fact, it is interesting to note that Act I scene 2 involves a battle between Duncan and rebel forces aided by another nation. Power seems to be presented from the opening of the play as something that necessary involves murder and blood in order to either gain it or preserve it. In this sense, Duncan is not that much different from Macbeth, as both are shown to need to shed blood in order to gain or maintain their position of power.
If we have a look at Act I scene 2, which is when Duncan receives word from the Captain about the progress of the battle that is raging between his forces and the rebel forces, blood is mentioned at two points, starting at the first line, when Duncan draws attention to the Captain's state by saying "What bloody man is that?" In the Captain's response, he says that Macbeth's sword "smoked with bloody execution." Of course, note the way that blood is associated with Macbeth through this metaphor. This effectively foreshadows the close link that there will be between Macbeth and blood during the play.