They can't actually do anything useful with the lactate. But that doesn't mean that other cells, specialized cells of our body, cannot actually use the lactate for something special, for something useful. In fact, two specialized types of cells that can and do use lactate produced by red blood cell and skeleton muscle cells are cardiac muscle cells and liver cells. So what is the ultimate fate of lactate? Well, once lactate moves across the membrane of these erythrocytes and skeletal muscle cells and enters the bloodstream of our cardiovascular system, the blood plasma, it generally ends up in one of two locations cardiac muscle cells and liver cells. And so let's focus on the following diagram as we go along this text.