What is the fine-grained topic of the following text: High local Mg concentrations near the intercellular junction also can affect the activities of local membrane-associated proteins (eg, sodium-potassium adenosine triphosphate [Na-K ATPase]) near the tight junction and affect its permeability (see Fig. Only return the topic.
The effects of high local Magnesium concentrations on the activities of local membrane-associated proteins and permeability of intercellular junctions.