title: Hypothalamic nitric oxide synthase gene expression is regulated by thyroid hormones.
abstract: We investigated the effects of thyroid status on nitric oxide synthase (NOS) gene expression in the rat hypothalamic paraventricular (PVN) and supraoptic nuclei (SON). Propylthiouracil (PTU)-induced hypothyroidism in male rats produced a highly significant reduction in NOS gene transcripts in the PVN and SON, as assessed by quantitative in situ hybridization histochemistry with a specific oligodeoxynucleotide probe. The addition of T3 (40 micrograms/kg) to the PTU-containing diet completely prevented the reduction in NOS transcripts. Hyperthyroidism, induced by adding 160 micrograms/kg T3 to the food, more than doubled the prevalence of NOS transcripts in the PVN and SON after a similar time. Up-regulation of NOS gene transcripts induced by the osmotic stimulus of chronic salt loading was markedly attenuated by PTU-induced hypothyroidism. These results demonstrate a major effect of thyroid status on regulation of NOS gene expression in the hypothalamus.
authors.affiliation: Department of Medicine, University of Bristol, Bristol Royal Infirmary, United Kingdom.
authors.forename: Y
authors.initials: Y
authors.lastname: Ueta
authors.forename: A
authors.initials: A
authors.lastname: Levy
authors.forename: H S
authors.initials: HS
authors.lastname: Chowdrey
authors.forename: S L
authors.initials: SL
authors.lastname: Lightman
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D007031:Hypothalamus / Q000201:enzymology*; D008297:Male; D008969:Molecular Sequence Data; D019001:Nitric Oxide Synthase; D011441:Propylthiouracil / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013963:Thyroid Hormones / Q000502:physiology*; D013972:Thyrotropin / Q000235:genetics; D013973:Thyrotropin-Releasing Hormone / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D013963:Thyroid Hormones; D013973:Thyrotropin-Releasing Hormone; D011441:Propylthiouracil; D013972:Thyrotropin; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases