蛋白激酶C激活剂对缺氧性动脉高压大鼠离体肺动脉环反应性？…

观察缺氧性动脉高压大鼠离体肺动脉环对蛋白激酶激活剂豆蔻酸佛波酰乙酰的反应性变化。方法取缺氧２周并已经形成肺动脉高压的大鼠和正常对照组大鼠肺动脉环，观察在离体情况下对０．５μｍｏｌ／ＬＰＭＡ的最大张力反应及达到二分之一最大张力所需的时间，并描绘两肺动脉环对０．０１－１０．０μｍｏｌ／ＬＰＭＡ的浓度－反应曲线。

The increased reactivity of isolated pulmonary artery rings from rats with hypoxia-induced pulmonary hypertension to activator of protein kinase C]

OBJECTIVE: To observe the reactivity of isolated pulmonary artery rings from rats with chronic hypoxic pulmonary hypertension (HPH) to protein kinase.C (PKC) activator. METHODS: Pulmonary artery rings from adult rats exposed to normobaric hypoxia for two weeks and normal rats were isolated for measurement of isometric contractions to PMA, the specific activator of PKC. Responses were examined as follows: (1) The maximal response (P(1)) to 0.5 micromol/L PMA and the time required to achieve a half-maximal response to 0.5 micromol/L PMA (t(1/2)); (2) Dose-response curve in response to PMA (0.01 - 10.0 micromol/L) and the dose of PMA that produced a contractile response as 50% of the maximal response (P(0)) to 80 mmol/L KCl (EC(50) KCl). RESULTS: P(1) of hypoxic group (34.3 +/- 2.4) P(0)% was greater than that of normal group (26.2 +/- 2.9) P(0)%, n = 6, P < 0.05)], t(1/2) and EC(50) KCl of hypoxic group (27 +/- 7) min, and (0.7 +/- 0.1) micromol/L] were smaller than those of normal group (32 +/- 5) min, n = 6, P < 0.05, and (6.0 +/- 0.2) micromol/L, n = 12, P < 0.05]. CONCLUSIONS: The reactivity of pulmonary artery rings from hypoxic rats to PMA was enhanced, which indicates that protein kinase C may have an important role in the development of HPH.