Makropinotsütoos

Makropinotsütoos is a form of endotsütoos, a cellular process where cells engulf large particles from their extracellular environment. It is distinct from phagotsütoos, which involves the specific engulfment of solid particles by specialized cells like macrophages and neutrophils. Instead, makropinotsütoos is characterized by the non-specific uptake of fluid-phase substances, including solutes, proteins, and even small extracellular vesicles. This process is often referred to as "cell drinking" due to its fluid-uptake nature.

The mechanism of makropinotsütoos involves the invagination of the plasma membrane, forming large vesicles. These vesicles, often referred to as makroinotsütoos vesicles, can be quite substantial in size, ranging from 0.5 to 5 micrometers in diameter. Unlike receptor-mediated endotsütoos, makropinotsütoos does not rely on specific receptors on the cell surface to initiate uptake. Instead, it is often triggered by changes in the extracellular environment, such as the presence of certain growth factors or changes in ion concentration.

Makropinotsütoos plays a crucial role in various physiological processes. It is involved in nutrient uptake, waste removal, and the transport of molecules across cellular barriers. In some cases, it can also contribute to the immune response by capturing and presenting extracellular antigens. Furthermore, makropinotsütoos is utilized by certain pathogens for cellular entry. The study of makropinotsütoos is important for understanding cellular physiology, drug delivery mechanisms, and the pathogenesis of diseases.