Iodothyronine 5'-deiodinase is present in mouse sublingual gland.

Abstract:

:Homogenates from male ddy mouse sublingual glands were incubated with 100 nM [125I]rT3 in the presence of 2 mM dithiothreitol (DTT). Metabolites were analyzed by HPLC or Dowex-50 minicolumn assay. 3,3'-Diiodothyronine and I- were the only appreciable products. Iodide release from rT3 was compatible with the enzymatic nature. The Km and maximum velocity from three separate determinations were 326, 356, and 629 nM and 29.8, 42.1, and 31.3 pmol I- release/mg protein.min, respectively. The deiodinase activity was DTT dependent and had higher affinity for rT3 than for T4 or T3. 6-Propyl-2-thiouracil inhibited the deiodination, which was competitively overcome by DTT. Sublingual 5'-deiodinase activity was approximately 80% of that in the liver, while the submandibular gland showed no deiodination. Our results show the presence of 5'-deiodinase (type I) in mouse sublingual gland for the first time. Selective localization and abundance of the enzyme suggest a previously unrecognized role of the sublingual gland in thyroid hormone physiology.

journal_name

Endocrinology

journal_title

Endocrinology

authors

Tanaka K,Imura H

doi

10.1210/endo.132.3.8440180

subject

Has Abstract

pub_date

1993-03-01 00:00:00

pages

1195-8

issue

3

eissn

0013-7227

issn

1945-7170

journal_volume

132

pub_type

杂志文章