Enhancement of DNA Polymerase β Activity in the Pituitary Gland by Hormonal Feedback

A. Nagasaka; S. Yoshida; Rumi Masunaga; S. Kato; Motoko Kotake; A. Nakai; T. Kawabe; T. Tsujimura; Asako Inagaki; K. Iwase

doi:10.1055/s-2007-1002132

Hormone and Metabolic Research, Table of Contents

Horm Metab Res 1993; 25(8): 403-406
DOI: 10.1055/s-2007-1002132

Originals Basic

Enhancement of DNA Polymerase β Activity in the Pituitary Gland by Hormonal Feedback

A. Nagasaka¹ , S. Yoshida² , Rumi Masunaga¹ , S. Kato¹ , Motoko Kotake¹ , A. Nakai¹ , T. Kawabe¹ , T. Tsujimura³ , Asako Inagaki³ , K. Iwase³

¹Department of Internal Medicine, Fujita Health University School of Medicine, Toyoake, Aichi
²Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Showa-ku, Nagoya, Japan
³Department of Surgery, Fujita Health University School of Medicine, Toyoake, Aichi

Abstract

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Summary

The activity of DNA polymerase β (β-enzyme) in bovine and rat pituitary glands was remarkably higher in the anterior than in the posterior lobe. In sucrose gradient centrifugation, the activity in the anterior lobe of the bovine pituitary gland appeared at the sedimentation constant, 3.3 S, while that of rat pituitary gland appeared at 3.3 S, 7.3 S and 12 S, respectively. The activity in each fraction increased in the anterior lobes of rat pituitaries that were stimulated to release TSH by decreased thyroid hormone levels induced by an antithyroid drug. These results suggest that the activity of the β-enzyme is high in the cells of the anterior lobe which are hyperfunctioned to produce pituitary thyreotrophic hormone and may be controlled by hormonal feedback regulation.

Key words

DNA Polymerase - Pituitary Gland - Hypothyroidism

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