Giannopoulos G, Smith S K
Life Sci. 1982 Aug 23;31(8):795-802. doi: 10.1016/0024-3205(82)90707-x.
Explants of fetal rabbit lung were established on the 25th day of gestation. These were maintained in serum-free medium for periods up to 10 days. During this time, the cultures exhibited morphological changes typical of terminal lung differentiation. Morphological evidence was also obtained for synthesis and secretion of pulmonary surfactant in these explants. beta-Adrenergic receptors were identified in these lung explants. Exposure of the explants to 10(-7)M dexamethasone on the third day of culture resulted in a significant increase in the number of beta-adrenergic receptors in the tissue without a change in receptor affinity. The effect of dexamethasone in organ culture was dose-dependent, a maximum increase in receptor number being observed within 48 hours of incubation with a hormone concentration of 1 x 10(-7)M. Exposure of the explant tissue to 1 x 10(-7)M triiodothyronine resulted in no significant increase in the concentration of beta-adrenergic receptors and no change in receptor affinity. These results suggest that glucocorticoids may potentiate the effects of beta-adrenergic agents in the fetal lung by increasing the numbers of their receptors. The effects of triiodothyronine upon the fetal lung do not appear to be mediated by this mechanism.
在妊娠第25天获取胎兔肺组织外植体。将这些外植体在无血清培养基中培养长达10天。在此期间，培养物呈现出终末肺分化的典型形态学变化。还获得了这些外植体中肺表面活性物质合成和分泌的形态学证据。在这些肺外植体中鉴定出了β-肾上腺素能受体。在培养的第三天将外植体暴露于10(-7)M地塞米松，导致组织中β-肾上腺素能受体数量显著增加，而受体亲和力没有变化。地塞米松在器官培养中的作用是剂量依赖性的，在与1×10(-7)M激素浓度孵育48小时内观察到受体数量最大增加。将外植体组织暴露于1×10(-7)M三碘甲状腺原氨酸，导致β-肾上腺素能受体浓度没有显著增加，受体亲和力也没有变化。这些结果表明，糖皮质激素可能通过增加β-肾上腺素能药物的受体数量来增强其在胎肺中的作用。三碘甲状腺原氨酸对胎肺的作用似乎不是通过这种机制介导的。
