Thyroid hormone differentially regulates cellular development in neonatal rat heart and kidney.

Published

Journal Article

The role of thyroid hormone in the control of cardiac and renal cell development was examined in neonatal rats made hyperthyroid by administration of triiodothyronine (T3, 0.1 mg/kg s.c. on postnatal days 1-5) or hypothyroid by administration of propylthiouracil (PTU, 20 mg/kg s.c. given to dams on gestational day 17 through postnatal day 5 and to pups on postnatal days 1-5). Indices of total cell number (total DNA per tissue), cell packing density (DNA per g tissue), and relative cell size (protein/DNA ratio) were evaluated from birth through young adulthood. PTU administration led to primary shortfalls in cell number that were of similar magnitude in both tissues, but persisted somewhat longer in the kidney than in the heart. Deficits in cell packing density and cell size in the hypothyroid animals were secondary to the effect on cell number, displaying smaller magnitudes of effect and a lag in appearance and disappearance of the deficits compared to that for total DNA; indeed, the phase in which tissues were restoring their cell numbers was accompanied by increased cell packing density, reflecting a more rapid restitution of cell numbers than tissue weight or cell size. In contrast to the relatively similar effects of PTU on developing cardiac and renal cells, the effects of T3 were selective for the heart. Although T3 caused general growth impairment, it evoked marked cardiac overgrowth that was accompanied by a striking increase in cell number and a small increase in cell size. The cardiac hyperplasia is unique to the developing animal, as post-replicative heart cells in adult animals show only hypertrophy in response to thyroid hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

Full Text

Duke Authors

Cited Authors

  • Slotkin, TA; Seidler, FJ; Kavlock, RJ; Bartolome, JV

Published Date

  • March 1992

Published In

Volume / Issue

  • 45 / 3

Start / End Page

  • 303 - 312

PubMed ID

  • 1631783

Pubmed Central ID

  • 1631783

International Standard Serial Number (ISSN)

  • 0040-3709

Digital Object Identifier (DOI)

  • 10.1002/tera.1420450309

Language

  • eng

Conference Location

  • United States