title: Suppression of cytoplasmic Ca2+ response and protein secretion by oxidizing agents.
abstract: The influence of the oxidizing agents (H2O2, KO2 and Vitamin K) on the action of vasopressin to guinea pig hepatocytes was investigated from the view-point of cytoplasmic Ca2+ concentration and protein secretion. 10 nmol/l vasopressin brought about increase in prothrombin secretion along with increase in the cytoplasmic Ca2+ concentration compared to the non-stimulation level. The pretreatment of the cells with 1 mumol/l of the oxidizing agents, however, led to suppression of Ca2+ elevation and inhibited the vasopressin-induced prothrombin secretion completely, while no leak if lactic dehydrogenase (LDH), Na+ and K+ were detected. The same results of the inhibition in fibrinogen and albumin secretion were observed. These results suggested a possibility that the oxidizing agents such as the peroxides act on some site of cellular signal transduction system in cell membrane to reduce the cytoplasmic Ca2+ level and to suppress the vasopressin-induced secretion.
authors.affiliation: Department of Biochemistry, Toho University School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tomono
authors.forename: T
authors.initials: T
authors.lastname: Urayama
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006168:Guinea Pigs; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D011516:Prothrombin / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013481:Superoxides / Q000494:pharmacology; D014812:Vitamin K / Q000494:pharmacology
chemical_list: D013481:Superoxides; D014812:Vitamin K; C039316:potassium superoxide; D011516:Prothrombin; D012964:Sodium; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D011188:Potassium; D002118:Calcium