血管紧张素Ⅱ和醛固酮对培养的心脏成纤维细胞胶原代谢的影响

EFFECTS OF ANGIOTENSIN Ⅱ AND ALDOSTERONE ON COLLAGEN METABOLISM OF CULTURED CARDIAC FIBROBLASTS

为探讨血管紧张素Ⅱ (AngⅡ )和醛固酮 (Ald)对培养的心脏成纤维细胞胶原合成量、胶原酶活力的影响。培养SD大鼠心脏成纤维细胞 ,以天狼星红法测定胶原合成总量 ;竞争ELISA法测定Ⅰ型胶原含量 ;荧光分光光度法测定胶原酶活性。结果显示 :心脏成纤维细胞在 10 -9～ 10 -7mol/L的AngⅡ作用下 ,胶原合成总量较对照组有显著增加 ,其中AngⅠ型胶原含量也较对照组有显著增加 ;在此浓度范围内 ,AngⅡ显著抑制培养细胞分泌的前胶原酶活性 ;AngⅡ受体拮抗剂Saralasin可拮抗上述作用。实验观察到 ,在较高浓度下 ,Ald能增加培养细胞 2 4h (10 -7mol/L)和 48h(10 -8～ 10 -7mol/L)胶原总量 ;10 -8～ 10 -7mol/LAld作用 2 4h后 ,培养基中Ⅰ型胶原含量显著升高 ;Ald的此作用可被螺旋内酯拮抗 ;同时 ,10 -9～ 10 -7mol/LAld均可在 2 4h后使培养细胞分泌的前胶原酶活性受到抑制 ,10 -6mol/L的螺旋内酯不能拮抗此作用。提示 :AngⅡ和Ald均能不同程度地促进胶原合成 ,抑制胶原酶活力 ,使胶原沉积的净效应增加 ,从而加速心肌纤维化。

To explore the influence of angiotensinⅡ(AngⅡ) and aldosterone (Ald) on synthesis of collagen and activity of precollagenase secreted by cardiac fibroblasts Sirus Red method was employed to evaluate collagen synthesis of cultured cardiac fibroblasts; typeⅠ collagen was measured by competitive ELISA; collagenase activity was tested by fluorescence spectrophotometry At the doses of 10 -9 ～10 -7 mol/L, AngⅡ could enhance gross and typeⅠ collagen production in a dose dependent manner. Collagenase activity decreased with increasing concentration of AngⅡ These effects of AngⅡcould be completely abolished by its receptor antagonist, saralasin Ald might enhance gross and typeⅠ collagen production only at a higher concentration (10 -7 ～10 -8 mol/L), whereas lower concentration (10 -9 mol/L) had no effect on it. These effects of Ald could be abolished by spironolactone,a specific Ald receptor antagonist In addition, Ald could significantly decrease the activity of collagenase secreted from cultured cardiac fiboblasts at concentrations of 10 -9 ～10 -7 mol/L within 24h,which could not be antagonized by 10 -6 mol/L spironolactone The results suggested that AngⅡand Ald enhance cardiac fibroblasts collagen synthesis and inhibit collagenase activity ,resulting in net collagen accumulation resulted and acceleration of cardiac fibrosis