King A P, Smith P, Heath D
Department of Pathology, University of Liverpool, UK.
J Pathol. 1995 Sep;177(1):71-81. doi: 10.1002/path.1711770112.
A group of rats was born in and spent the first 4 weeks of life at a simulated altitude of 3550 m. Two animals were killed immediately afterwards and the remaining 16 were allowed to recover for various times up to a maximum of 12 weeks at sea-level atmospheric pressure. On ultrastructural examination, the pulmonary arterioles of hypoxic rats showed muscularization, the new layer of mature smooth muscle cells containing abundant organelles and myofilaments. These cells were bounded by prominent elastic laminae. During the recovery period, the medial layer became progressively thinned, but the cells still retained some characteristics of smooth muscle by 12 weeks' recovery. When a similar group of ten hypoxic rats was allowed to recover for 12 weeks before being given monocrotaline, there was early enlargement of the residual smooth muscle cells in the media of pulmonary arterioles and within 5 weeks there was again a thick layer of medial smooth muscle. This was in contrast to the sparse, weakly muscularized arterioles seen in eight similarly treated rats born under normoxic conditions. The relevance is discussed of these findings to the rare occurrence of primary pulmonary hypertension in people who were born at high altitude but returned to sea-level during childhood.
一组大鼠出生并在模拟海拔3550米的环境中度过生命的前4周。之后立即处死2只动物，其余16只在海平面大气压下恢复不同时间，最长为12周。超微结构检查显示，缺氧大鼠的肺小动脉出现肌化，新的成熟平滑肌细胞层含有丰富的细胞器和肌丝。这些细胞由明显的弹性膜界定。在恢复期，中层逐渐变薄，但到恢复12周时，细胞仍保留一些平滑肌特征。当一组类似的10只缺氧大鼠在给予野百合碱前恢复12周时，肺小动脉中层残留的平滑肌细胞早期增大，5周内又出现一层厚厚的中层平滑肌。这与在常氧条件下出生的8只接受类似治疗的大鼠中所见的稀疏、弱肌化的小动脉形成对比。讨论了这些发现与出生在高海拔但童年时返回海平面的人群中罕见的原发性肺动脉高压发生情况的相关性。
