title: Phorbol myristate acetate stimulates pinocytosis and membrane spreading in mouse peritoneal macrophages.
abstract: Phorbol myristate acetate (PMA) at a concentration of 0.01 microgram/ml causes an approximately threefold increase in surface area of resident, proteose-peptone-elicited, and thioglycolate-broth-elicited mouse peritoneal macrophages. Resident and proteose-peptone-elicited macrophages, cultured for 24 h in the presence of PMA, increase their pinocytic rate twofold in response to addition of PMA (0.01 microgram/ml) to the medium. Thioglycolate-broth-elicited macrophages, cultured for 24 h in the absence of PMA, immediately increase their pinocytic rate 2- to 3.5-fold in response to a single challenge with PMA (0.01 microgram/ml). Cytochalasin B, colchicine, and podophyllotoxin have only modest inhibitory effects on the basal rate of pinocytosis and on PMA-induced cellular spreading, but completely block the stimulatory effects of PMA on pinocytosis in thioglycolate-broth-elicited macrophages. Cytochalasin D markedly inhibits both basal and PMA-stimulated pinocytosis in these cells. Thus, PMA is a useful tool for studying mechanisms of macrophage spreading and for enhancing the overall rate of pinosome formation.
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology; D002465:Cell Movement / Q000187:drug effects; D003078:Colchicine / Q000494:pharmacology; D003572:Cytochalasins / Q000494:pharmacology; D004705:Endocytosis; D006735:Horseradish Peroxidase / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D010704:Phorbols / Q000494:pharmacology*; D010873:Pinocytosis / Q000187:drug effects*; D011034:Podophyllotoxin / Q000494:pharmacology; D013268:Stimulation, Chemical; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D003572:Cytochalasins; D010704:Phorbols; D006735:Horseradish Peroxidase; D011034:Podophyllotoxin; D013755:Tetradecanoylphorbol Acetate; D003078:Colchicine