Lysosomal enzyme secretion from human placental villi is increased by serum albumin and IgG.
Human serum albumin and IgG increased the secretion of the lysosomal enzyme, beta-hexosaminidase, from human placental villi in a dose- and time-dependent manner. Release was also enhanced by bovine serum albumin and ovalbumin. beta-Hexosaminidase secretion was not increased by the non-endocytosable substrate, IgG-Sepharose, indicating that the signal for release is not given by the interaction of protein with the cell surface. Experiments with 125I-labelled albumin and IgG showed that both proteins were actively internalised by placental villi giving credence to the idea that secretion is triggered after uptake.
D002824:Chorionic Villi / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006596:Hexosaminidases / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G; D008247:Lysosomes / Q000201:enzymology*; D010047:Ovalbumin / Q000494:pharmacology; D010873:Pinocytosis; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D012709:Serum Albumin / Q000494:pharmacology*; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D001619:beta-N-Acetylhexosaminidases
D007074:Immunoglobulin G; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D010047:Ovalbumin; D006596:Hexosaminidases; D001619:beta-N-Acetylhexosaminidases