What is the significance of pinocytosis?

In higher organisms, pinocytosis plays a crucial role for the bulk transport of dissolved molecules. Since pinocytosis absorbs molecules in a nonspecific manner, it allows the transport of a large quantity of different molecules at the same time. Additionally, pinocytosis is involved in the removal of waste materials out of cells. For example, it assists in the process of kidneys removing water and waste products into urine and thus is important for fluid homeostasis as well. Pinocytosis is also significant as it is used by immune system cells such as dendritic cells and macrophages as a method of testing the extracellular fluid for the presence of antigens. Additionally, pinocytosis allows cells to take in nutrients such as ions, sugars, and amino acids that are dissolved in the extracellular fluid. This is important as cells can uptake their molecules and ions for their necessary functions.