Immunohistochemical localization of inducible and endothelial constitutive nitric oxide synthase in neoplastic and autoimmune thyroid disorders.
OBJECTIVE
To investigate the distribution of nitric oxide synthase in tissues derived from patients with autoimmune or neoplastic disorders of the thyroid gland in order to test whether the expression of inducible nitric oxide synthase or endothelial constitutive nitric oxide synthase (two subtypes of EC 1.14.13.39) may be related to the inflammatory activity or degree of neoplasia.


METHODS
The expression of nitric oxide synthases was examined by immunohistochemistry in tissues from patients with either Hashimoto's thyroiditis (n=6), hyperplastic glands (Graves' disease) (n=7), adenomas (n=8), multinodular goitres (n=7), papillary carcinomas (n=4) or follicular carcinomas (n=5).


RESULTS
Expression of inducible nitric oxide synthase was found in 22 of the tissues and was not specific for any of the examined thyroid disorders. Expression of endothelial constitutive nitric oxide synthase was found in some of the epithelial cells in all the tissues. There was no correlation between the intensity and distribution of the immunostaining and the thyroid disorders.


CONCLUSIONS
Demonstration of nitric oxide synthase cannot be used for diagnostic purposes. The expression of endothelial constitutive nitric oxide synthase in all tissues indicates that the enzyme may be of importance for the function or growth of the thyroid epithelial cells.
Kayser
L
L
Department of Medical Anatomy, Section A, Panum Institute, Copenhagen, Denmark. l.kayser@mai.ku.dk
Francis
D
D
Broholm
H
H
D018263:Adenocarcinoma, Follicular / Q000201:enzymology; D000236:Adenoma / Q000201:enzymology; D002291:Carcinoma, Papillary / Q000201:enzymology; D004847:Epithelial Cells / Q000201:enzymology; D006042:Goiter / Q000201:enzymology*; D006111:Graves Disease / Q000201:enzymology*; D006801:Humans; D007150:Immunohistochemistry; D019001:Nitric Oxide Synthase / Q000032:analysis*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D013961:Thyroid Gland / Q000201:enzymology*; D013964:Thyroid Neoplasms / Q000201:enzymology*; D013967:Thyroiditis, Autoimmune / Q000201:enzymology*
C496319:NOS2 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III