Hydrogen peroxide generation and its regulation in FRTL-5 and porcine thyroid cells. 1992

U Björkman, and R Ekholm
Department of Anatomy, University of Goteborg, Sweden.

Hydrogen peroxide acts as electron acceptor in the oxidative reactions (iodination and coupling) by which the thyroid hormones are formed. Regulation of the generation of H2O2 was studied in monolayer cultures of the FRTL-5 rat thyroid cell line and in primary monolayer cultures of porcine thyroid cells. Both cell types were grown in a medium containing either a six-hormone mixture, including TSH (6H), or a five-hormone mixture without TSH (5H) for 1 to several days before the experiment. The production of H2O2 was measured with the homovanillic acid fluorescence assay and expressed as picomoles of H2O2 formed per min/microgram DNA. In FRTL-5 cells grown in 6H medium, only a weak and varying stimulation of H2O2 production was induced by TSH at high concentration (greater than 10 mU/ml), and no stimulation was seen by TSH at low concentration or by 8-bromo-cAMP, whereas forskolin had a good stimulatory effect. In FRTL-5 cells grown in 5H medium for 1-3 days, all three substances were potent stimulators. In porcine thyrocytes examined in the same way, none of the three presumptive stimulators had any effect in 6H cultures, and only TSH (at high concentration) had a weak effect in 5H medium. ATP, a stimulator of the Ca2+/phosphatidylinositol cascade via a P2-purinergic receptor, had no effect on H2O2 generation in FRTL-5 cells in 6H medium. Phorbol myristate acetate (PMA), a direct activator of protein kinase-C, induced a weak stimulation in these cells. In FRTL-5 cells in 5H medium, both ATP and PMA evoked a strong, and similar, enhancement of H2O2 production. In porcine cells in 6H medium, ATP evoked a moderate and PMA a strong stimulation; the effects in 5H were similar to the corresponding effects in 6H medium. The observations are interpreted to show that in FRTL-5 cells the regulation of H2O2 generation uses both the cAMP cascade and the Ca2+/phosphatidylinositol cascade, whereas in porcine thyrocytes the cAMP route is unimportant. In FRTL-5 cells the Ca2+/phosphatidylinositol cascade may be influenced by the cAMP system.

UI MeSH Term Description Entries
D010716 Phosphatidylinositols Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids. Inositide Phospholipid,Inositol Phosphoglyceride,Inositol Phosphoglycerides,Inositol Phospholipid,Phosphoinositide,Phosphoinositides,PtdIns,Inositide Phospholipids,Inositol Phospholipids,Phosphatidyl Inositol,Phosphatidylinositol,Inositol, Phosphatidyl,Phosphoglyceride, Inositol,Phosphoglycerides, Inositol,Phospholipid, Inositide,Phospholipid, Inositol,Phospholipids, Inositide,Phospholipids, Inositol
D002118 Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002460 Cell Line Established cell cultures that have the potential to propagate indefinitely. Cell Lines,Line, Cell,Lines, Cell
D006861 Hydrogen Peroxide A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials. Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D000242 Cyclic AMP An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH. Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic
D000255 Adenosine Triphosphate An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter. ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D013552 Swine Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA). Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D013755 Tetradecanoylphorbol Acetate A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA. Phorbol Myristate Acetate,12-Myristoyl-13-acetylphorbol,12-O-Tetradecanoyl Phorbol 13-Acetate,Tetradecanoylphorbol Acetate, 4a alpha-Isomer,12 Myristoyl 13 acetylphorbol,12 O Tetradecanoyl Phorbol 13 Acetate,13-Acetate, 12-O-Tetradecanoyl Phorbol,Acetate, Phorbol Myristate,Acetate, Tetradecanoylphorbol,Myristate Acetate, Phorbol,Phorbol 13-Acetate, 12-O-Tetradecanoyl,Tetradecanoylphorbol Acetate, 4a alpha Isomer
D013961 Thyroid Gland A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively. Thyroid,Gland, Thyroid,Glands, Thyroid,Thyroid Glands,Thyroids

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