Lijnen Paul, Petrov Victor, Rumilla Kandelaria, Fagard Robert
Department of Molecular and Cardiovascular Research, University of Leuven, Belgium.
J Renin Angiotensin Aldosterone Syst. 2002 Sep;3(3):160-6. doi: 10.3317/jraas.2002.036.
The aim of the present study was to investigate whether angiotensin II (Ang II), angiotensin III (Ang III) or Ang II (2-8), angiotensin IV (Ang IV) or Ang II (3-8) and Ang II (1-7), Ang II (4-8), Ang II (5-8) and Ang II (1-4) can stimulate collagen gel contraction in cardiac fibroblasts in serum-free conditions.
Cardiac fibroblasts (from male adult Wistar rats) from passage 2 were cultured to confluency and added to a hydrated collagen gel in a Dulbecco's Modified Eagle's Medium, with or without foetal bovine serum, for one, two or three days. The area of the collagen gels embedded with cardiac fibroblasts was determined by a densitometric analysis. Collagen gel contraction was characterised by a decrease in the gel area.
Ang II dose-dependently stimulated the contraction of collagen mediated by cardiac fibroblasts after one, two or three days of incubation in a serum-free medium. Telmisartan completely blocked the Ang II-induced collagen contraction by cardiac fibroblasts. PD 123319 and des-Asp(1)-Ile(8)-Ang II had no effect on the Ang II-induced collagen contraction by cardiac fibroblasts. Ang III also stimulated the contraction of collagen mediated by cardiac fibroblasts after one, two or three days of incubation in a serum-free medium. des-Asp(1)-Ile(8)-Ang II and telmisartan completely blocked the Ang III-induced collagen gel contraction by cardiac fibroblasts. des-Asp(1)-Ile(8)-Ang II, however, had no effect on the Ang II-induced collagen gel contraction by cardiac fibroblasts. Ang IV and Ang II (4-8), (5-8), (1-7) and (1-4), however, had no effect on collagen gel contraction by cardiac fibroblasts. Addition of telmisartan, PD 123319 or des-Asp(1)-Ile(8)-Ang II alone did not affect collagen gel contraction by cardiac fibroblasts.
Our data demonstrate that the effects of Ang II on the collagen gel contraction by adult rat cardiac fibroblasts in serum-free conditions are Ang II type 1(AT(1))-receptor- mediated, because they are abolished by the specific AT(1)-receptor antagonist, telmisartan, and not by the AT(2)-receptor antagonist PD 123319 or by the Ang III antagonist des-Asp(1)-Ile(8)-angiotensin. The Ang III- stimulated contraction of collagen by cardiac fibroblasts is completely blocked by the Ang III receptor antagonist, des-Asp(1)-Ile(8)-angiotensin II, and by telmisartan.
本研究旨在探讨血管紧张素II（Ang II）、血管紧张素III（Ang III）或Ang II（2 - 8）、血管紧张素IV（Ang IV）或Ang II（3 - 8）以及Ang II（1 - 7）、Ang II（4 - 8）、Ang II（5 - 8）和Ang II（1 - 4）在无血清条件下能否刺激心脏成纤维细胞中的胶原凝胶收缩。
将第2代雄性成年Wistar大鼠的心脏成纤维细胞培养至汇合状态，然后添加到含有或不含有胎牛血清的杜氏改良 Eagle 培养基中的水合胶原凝胶中，培养1天、2天或3天。通过密度分析确定嵌入心脏成纤维细胞的胶原凝胶面积。胶原凝胶收缩的特征是凝胶面积减小。
在无血清培养基中孵育1天、2天或3天后，Ang II剂量依赖性地刺激心脏成纤维细胞介导的胶原收缩。替米沙坦完全阻断了Ang II诱导的心脏成纤维细胞胶原收缩。PD 123319和去天冬氨酸（1）-异亮氨酸（8）-Ang II对Ang II诱导的心脏成纤维细胞胶原收缩没有影响。在无血清培养基中孵育1天、2天或3天后，Ang III也刺激心脏成纤维细胞介导的胶原收缩。去天冬氨酸（1）-异亮氨酸（8）-Ang II和替米沙坦完全阻断了Ang III诱导的心脏成纤维细胞胶原凝胶收缩。然而，去天冬氨酸（1）-异亮氨酸（8）-Ang II对Ang II诱导的心脏成纤维细胞胶原凝胶收缩没有影响。然而，Ang IV和Ang II（4 - 8）、（5 - 8）、（1 - 7）和（1 - 4）对心脏成纤维细胞的胶原凝胶收缩没有影响。单独添加替米沙坦、PD 123319或去天冬氨酸（1）-异亮氨酸（8）-Ang II不影响心脏成纤维细胞的胶原凝胶收缩。
我们的数据表明，在无血清条件下，Ang II对成年大鼠心脏成纤维细胞胶原凝胶收缩的作用是由1型Ang II（AT(1)）受体介导的，因为它们被特异性AT(1)受体拮抗剂替米沙坦消除，而不是被AT(2)受体拮抗剂PD 123319或Ang III拮抗剂去天冬氨酸（1）-异亮氨酸（8）-血管紧张素消除。心脏成纤维细胞中Ang III刺激的胶原收缩被Ang III受体拮抗剂去天冬氨酸（1）-异亮氨酸（8）-血管紧张素II和替米沙坦完全阻断。
