缺氧幼猪离体肺小动脉^3H—磷酸肌醇及组织多胺含量的变化

Changes of polyamine contents in lung,arterial and ventricular tissues and phosphoinositide turnover in isolated pulmonary arterial tissue of normoxic and chronic hypoxic swines

实验结果：（１）平原幼猪离体肺小动脉组织在缺氧或缺氧＋组胺刺激时，［￣３Ｈ］－ＩＰｓ积累分别比其相应常氧对照高８．６倍和２３．１倍（Ｐ＜０．０１）；慢性缺氧组离休肺动脉刺激诱导的［￣３Ｈ］－ＩＰｓ积累与平原组显著不同。提示ＰＩＰ＿２降解参与缺氧性肺血管收缩细胞内信息传递：慢性缺氧可以改变动脉内刺激诱导的ＰＩＰ＿２的降解程度。（２）缺氧动物的肺、肺小动脉壁及右心室肌多胺含量显著高于平原组，并与肺动脉高压的发生，肺小动脉壁增厚和右心肥大相平行。

The results showed:1.Mean pulmonary arterial pressure and medial thick-ness of pulmonary arterioles wall were increased significantly in swine exposed to hypoxiaeither for 7 or 21 days.These changes were closely paralleled to the increases of polya-mine contents in lung and small pulmonary arterial tissues.Swines of both hypoxic groupsshowed significant increases in weight,Hermann-Wilson's index and polyamine contentsin right ventricle.2.After stimulations of hypoxia and hypoxic histamine,the accumula-tions of[￣3H]-inositol phosphates( IPs)of isolated tissue of small pulmonary artery wererespectively enhanced 8. 6 and 2 3.1 folds vs respective normoxia control in sea level group(P<0.01).In both hypoxic groups hypoxic histamine induced marked increases in accu-mulation of[￣3H]-IPs but in the 21-day hypoxic group hypoxic stimulation faileind toinduce the effect.These results suggest that polyamines may act as important intracellularregulators of hypoxic pulmonary vascular remodeling and right ventriculat hypertrophydeveloped in response to chronic hypoxia in swine.Hypoxia and/or some vasoactive sub-tancs might induce phosphatidylinositol-4,5-bisphosphate turnover which maybe is animportant machanism in the hypoxic pulmonary vasoconstriction. Chronic hypoxia maychange the reactivity of phosphoinositide system in smooth muscle of small pulmonaryarterial wall.