[Structural changes of extra pulmonary artery and pulmonary arterioles of rats during chronic hypoxia and their significance].
The structural changes of extra pulmonary artery (PA) and pulmonary arterioles and their effects on the pulmonary arterial pressure (PAP) under chronically hypobaric hypoxia (5000 m) were studied. The results showed that (1) The endothelial edema of extra PA and pulmonary arterioles gradually reduced and the endothelial proliferation took place along with the prolongation of hypoxic exposure followed by the recovery of endothelium-dependent relaxation evoked by Ach from depression. This result suggested that the release of E-DRFs from endothelium increased with the structural changes of endothelium in the course of hypoxic exposure, which may be a reason why PAP did not increase any more after 21 to 40 of days exposure. However, the strengthened contraction of PA, the proliferation of cells on the vascular wall, and the muscularity of pulmonary arterioles being related to the hypoxic endothelium may produce a negative effect on decrease of PAP, resulting in persistently higher PAP. (2) The structural changes of pulmonary arteriole endothelium were more severe than those of extra PA endothelium, indicating that pulmonary arterioles might be more sensitive to the stimulation of hypoxia.
Song
W
W
Institute of Basic Medical Sciences, CAMS, Beijing.
Cai
Y
Y
Deng
X
X
Gong
Y
Y
Dong
G
G
D000532:Altitude Sickness / Q000150:complications*; D000818:Animals; D001160:Arterioles / Q000473:pathology; D004730:Endothelium, Vascular / Q000648:ultrastructure*; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000473:pathology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D011651:Pulmonary Artery / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar