[Physico-chemical mechanisms of transport by micropinocytosis].
Blood plasma proteins adsorption on a capillar endoteliocyte membrane surface can be accompanied by the formation of protein clusters. Their superficial protein density is about 10(16) protein globules per m2. The surface density of free energy of such protein layer in a cluster is estimated according to total energy of individual protein globules hydrophobic contribution, and its value is approximately 5 mJ X m-2. It is identical to local variation quantity of the membrane free energy. An alternation of the free surface energy must lead to the appearance of chemically induced and bending moments and to the membrane distortion accompanied by the caveole forming. The blood hydrostatic pressure in capillar lumen (approximately 33 X 10(2)N X m-2) creates the membrane isotropic tension which is proportional to its value and to caveole radius. The latter according to Laplas' equation closes the caveole into the vesicula with the radius approximately 40 nm. The transport of free vesicula by cytoplasmic currents to the basal surface of an endoteliocyte results in exocytosis (which proceeds approximately 0.1 s) with a release of the vesicula surface free energy (approximately 10(-16) J). The capillar endotelium vesicular transport is the indivisible endocytosis-exocytosis process characterized by "the turnover" of the cell plasmic membrane matter without its loss.
D001692:Biological Transport; D001798:Blood Proteins / Q000378:metabolism*; D002199:Capillary Permeability; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008954:Models, Biological; D010873:Pinocytosis; D011485:Protein Binding
D001798:Blood Proteins
Fiziko-khimicheskie mekhanizmy transporta posredstvom mikropinotsitoza.