title: Postnatal development of pulmonary alveoli: modulation in rats by thyroid hormones.
abstract: We studied the effect of thyroid hormones on the postnatal development of the gas exchange region of rat lungs. Treatment with triiodothyronine (T3, 0.1 microgram . g body wt-1 . day-1) accelerated the increase of the surface-to-volume ratio (S/V) and surface area (Sa) and decrease of the mean chord length (Lm) of the gas exchange structures of pups killed at age 7 days. Propylthiouracil (PTU, 100 micrograms twice daily) from age 1 to 13 days, with death at age 14 days, diminished the rise of S/V and Sa and the fall of Lm compared with diluent-injected pups. Providing drinking water with 0.01% PTU to dams from gestation day 20 (term 22 days) to postnatal day 14 also diminished the rise of S/V and fall of Lm. Treatment of pups nursed by dams drinking 0.01% PTU with thyroxine (0.1 microgram/g body wt) every other day from age 1 to 13 days significantly diminished the effect of PTU on S/V, Sa, and Lm. We conclude thyroid hormones can modulate the postnatal architectural development of the gas exchange region of the rat lung.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development* / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008176:Lung Volume Measurements; D011441:Propylthiouracil / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000254:growth & development*; D051381:Rats; D011919:Rats, Inbred Strains; D013963:Thyroid Hormones / Q000502:physiology*; D013974:Thyroxine / Q000494:pharmacology; D014284:Triiodothyronine / Q000494:pharmacology
chemical_list: D013963:Thyroid Hormones; D014284:Triiodothyronine; D011441:Propylthiouracil; D004247:DNA; D013974:Thyroxine