Regulatory effect of lithium on thyroxine metabolism in murine neural and anterior pituitary tissue.

Abstract:

:The conversion of T4 to T3 in the brain and anterior pituitary gland contributes significantly to the T3 content of these tissues and appears to be an important modulator of thyroid hormone action. In the present study, the antimanic agent lithium was demonstrated in cultured neural and pituitary tissue to have a significant inhibitory effect on the activity of low Km (type II) iodothyronine 5'-deiodinase (I5'D), the enzyme mediating T3 formation. At medium lithium concentrations of 3.3-5 mM, 15'D activity was decreased 44 +/- 3% (P less than 0.001) in the NB41A3 mouse neuroblastoma cell line and 48 +/- 2% (P less than 0.001) in the GH3 rat pituitary tumor cell line. This inhibitory effect was only observed in intact cells. Significant inhibition of this enzymatic process was also noted in the anterior pituitary gland of thyroidectomized rats injected 3-24 h earlier with either 4 or 10 mmol/kg BW LiCl. This decrease in low Km I5'D activity was accompanied by significant decreases in the serum T3 concentration and the pituitary nuclear T3 content. Renal high Km (type I) I5'D activity was unaffected by lithium administration. These studies demonstrate that lithium, an agent of proven therapeutic benefit in patients with manic-depressive illness, can affect changes in T4 metabolism and cellular T3 content in neural and anterior pituitary tissue. Given the prominent mood changes that occur in patients with disordered thyroid function, this finding suggests that the therapeutic benefits of lithium in affective illness may be derived in part from alterations in thyroid hormone economy in the brain.

journal_name

Endocrinology

journal_title

Endocrinology

authors

St Germain DL

doi

10.1210/endo-120-4-1430

subject

Has Abstract

pub_date

1987-04-01 00:00:00

pages

1430-8

issue

4

eissn

0013-7227

issn

1945-7170

journal_volume

120

pub_type

杂志文章