Nitric oxide enhances thyroid peroxidase activity in primary human thyrocytes.
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.
Millatt
L J
LJ
Department of Cellular and Molecular Sciences, St. George's Hospital Medical School, London, United Kingdom. 1jm6n@virginia.edu
Johnstone
A P
AP
Whitley
G S
GS
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*
D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D009599:Nitroprusside; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D007453:Iodide Peroxidase; D019001:Nitric Oxide Synthase; D005978:Glutathione