The American Pit Bull Terrier is often referred to as a Bulldog by fanciers, so, I am sure some people would refer to them as American Pit Bulldogs. However, it isn't a whole different breed.
The American Bulldog breed was originally registered as American Pit Bulldogs, but the name was later changed to reduce confusion.
Also, many fanciers and dogmen refer to a game-bred APBT as a bulldog.