title: Nitric oxide enhances thyroid peroxidase activity in primary human thyrocytes.
abstract: Recent studies have demonstrated the production of the multi-functional messenger molecule nitric oxide (NO) by the thyroid gland. To examine a possible role for NO in thyroid function, we studied the acute and chronic effect of NO donors on thyroid peroxidase (TPO) activity in monolayer cultures of primary human thyrocytes, using a colorimetric assay technique. The presence of either S-nitrosoglutathione (GS-NO) or sodium nitroprusside (SNP) (10(-6)-10(-4) M) at the time of the assay caused a significant increase in TPO activity. Pre-incubation of thyrocytes with 10(-5) M GS-NO for 3 days had no effect on the level of TPO activity when the assay was performed in the absence of NO donors. However, GS-NO pre-incubation significantly enhanced the acute stimulatory effect of GS-NO and SNP on TPO activity. These results suggest a possible role for NO in the regulation of TPO activity and thus thyroid hormone synthesis.
authors.affiliation: Department of Cellular and Molecular Sciences, St. George's Hospital Medical School, London, United Kingdom. 1jm6n@virginia.edu
authors.forename: L J
authors.initials: LJ
authors.lastname: Millatt
authors.forename: A P
authors.initials: AP
authors.lastname: Johnstone
authors.forename: G S
authors.initials: GS
authors.lastname: Whitley
mesh_terms: D002478:Cells, Cultured; D005978:Glutathione / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D007453:Iodide Peroxidase / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D009603:Nitroso Compounds / Q000494:pharmacology; D026422:S-Nitrosoglutathione; D013961:Thyroid Gland / Q000166:cytology / Q000201:enzymology*
chemical_list: D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D009599:Nitroprusside; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D007453:Iodide Peroxidase; D019001:Nitric Oxide Synthase; D005978:Glutathione