Hormonal Regulation of DNA Polymerase ß Activity in Rat Thyroid Gland
Our previous studies provided the evidence that rat adrenal gland and testis contain three species of DNA polymerase, α, ß, and γ (1,2). Among them, the ß-enzyme activity in the endocrine organs was modulated by pituitary trophic hormones. Namely, the manipulation of hypophysectomy reduced the level of ß-enzyme activity and changed its molecular size. These changes were reversed by the administration of the pituitary trophic hormone to the hypophysectomized rat. Therefore, DNA polymerase ß activity may be strongly regulated by the feedback mechanism in these endocrine organs. Here we extended our work to another endocrine organ, the thyroid gland, which is regulated by TSH and shows some extent of autoregulation under the depletion of TSH.
KeywordsThyroid Gland Endocrine Organ Molecular Weight Form Sucrose Gradient Centrifugation High Molecular Weight Form
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