title: Calcium distribution within human erythrocytes during endocytosis.
abstract: In order to study 45Ca movements within erythrocytes, a method was devised that had minimal deleterious effect on the treated erythrocytes. Agents that induce endocytosis in intact erythrocytes (primaquine, vinblastine, and chlorpromazine) caused a prompt movement of 45Ca from cytosol to membrane-associated sites. This drug-induced movement of 45Ca to membrane sites was blocked by depleting erythrocytes of adenosine triphosphate (ATP) or by incubating them with known inhibitors of endocytosis, NaF of N-ethylmaleimide (NEM). It appears that endocytosis in intact human erythrocytes involves the movement and redistribution of 45Ca from cytosol to membrane-associated sites. Therefore, in the erythrocyte, as in perhaps other cells, movement of Ca from one site to another may modulate important cellular biologic functions.
mesh_terms: D000255:Adenosine Triphosphate / Q000097:blood; D002118:Calcium / Q000097:blood*; D002746:Chlorpromazine / Q000494:pharmacology; D004705:Endocytosis / Q000187:drug effects*; D004912:Erythrocytes / Q000502:physiology; D006801:Humans; D011319:Primaquine / Q000494:pharmacology; D014747:Vinblastine / Q000494:pharmacology
chemical_list: D014747:Vinblastine; D000255:Adenosine Triphosphate; D011319:Primaquine; D002118:Calcium; D002746:Chlorpromazine