中图分类号:R329.28文献标识码:A
文章编号:1005-3271(2000)03-0169-03
Effects of arginine vasopressin on collagen synthesis in rat cardiac fibroblasts
YANG Xue-dong,ZHAO Lian-you, LI Xue, XU Hai-li, QIAO Huai-yu, PENG Yu-hong, CHEN Yong- qing, FAN Yan-hong
(Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xi`an 710038, Shaanxi, China)
abstract: AIM: Arginine vasopressin(AVP) modulate cardiac fibroblasts(CFs) collagen synthesis was tested. METHODS: CFs of neonatal SD rat were isolated by trypsin digestion method and growth-arrested CFs were stimulated with 25 ml/L fetal calf serum in the presence of varying concentrations of AVP and 10-7mol/L V1 receptor antagonist [d(CH2)5Tyr2(Me)]AVP. Collagen synthesis was measured by 3H-proline incorporation. Collagen content of CFs culture medium was estimated by hydroxyproline chromatogragy. RESULTS: ①AVP increases 3H-proline incorporation in CFs in a concentration-dependent manner. 3H-proline incorporation value of 10-7mol/L and 10-6 mol/L AVP group(541±96 cpm/5000 cells, 565±72 cpm/5000 cells, respectively) were higher than that of control group(both P<0.01). 3H-proline incorporation value of 10-7mol/L AVP+10-7mol/L [d(CH2)5Tyr2(Me)]AVP group(268±64 cpm/5000 cells) was lower than that of 10-7mol/L AVP group(P<0.01). ②AVP increases A value of CFs culture medium in a concentration-dependent manner. A value of 10-7mol/L and 10-6mol/L AVP group (0.22±0.01, 0.24±0.01, respectively) were higher than that of control group 0.20±0.01 (both P<0.01). A value of 10-7mol/L AVP+10-7mol/L [d(CH2)5Tyr2(Me)]AVP group(0.19±0.01) were lower than that of 10-7mol/L AVP group(P<0.01). CONCLUSION: AVP increases collagen synthesis in rat CFs, which seems to be mediated through V1 receptor.
Keywords:arginine vasopressin; collagen synthesis; cardiac fibroblasts; rat
众多资料表明,心肌纤维化参与了高血压病心室重塑过程[1]。心肌纤维化可引起心功能障碍,表现在心肌僵硬度增加、心肌缺血和室性心律失常,是导致慢性心力衰竭的一个决定因子[2~4]。目前认为,心室负荷过重或血流动力学因素不是诱导心肌纤维化的主要因素,而体液因素在心肌纤维化发生、发展中发挥重要作用[5]。精氨酸加压素(AVP)是下丘脑分泌的神经内分泌多肽,具有明显的升高血压、抗利尿作用,其受体广泛存在心血管系统组织细胞中。现已证实,AVP和高血压病发生、发展密切相关[6],但AVP是否参与诱导心肌纤维化,国内外尚无报道。作者观察了AVP对SD大鼠CFs胶原合成的影响,以探讨AVP在心肌纤维化发生、发展中的意义。
1材料和方法
1.1主要试剂精氨酸加压素(美国Peninsular Lab);DMEM培养液(GIBCO); 胰蛋白酶和[d(CH2)5Tyr2(Me)]AVP均购于美国Sigma公司;胎牛血清(浙江金华市清湖犊牛利用研究所);3H-脯氨酸(中国原子能研究院同位素研究所);闪烁液为18.1 mmol/L PPO和271.7 μmol/L POPOP的二甲苯溶液。
1.2CFs分离、培养和鉴定
1.2.1CFs分离和培养 在无菌条件下取下出生后2~3 d的SD大鼠(第四军医大学实验动物中心提供)的心室,剪碎,DMEM冲洗,用1.25 g/L胰酶在37℃分离细胞,每5 min收集1次细胞。1000 r/min,离心2次,每次5 min,将所得全部细胞置于含100 ml/L胎牛血清的DMEM培养液的100 ml培养瓶中,在50 ml/L CO2,37℃孵箱中培养60~90 min,采用差速贴壁法分离CFs[7]。CFs贴壁速度较快,倒掉细胞悬液,贴壁的细胞主要是CFs。待CFs生长接近融合时以1∶3传代。实验采用3~4代CFs。
1.2.2CFs的鉴定 倒置显微镜下观察:细胞呈梭形、多角形,细胞质透明,细胞核明显大,呈椭圆形,常含有2~3个核。SABC法免疫组织化学染色:纤维连接蛋白染色阳性,血管平滑肌肌动蛋白染色阴性,符合成纤维细胞染色特征。
1.3CFs 3H-脯氨酸掺入的测定取对数生长期的CFs,2.5 g/L胰酶消化,用含100 ml/L胎牛血清的DMEM调节细胞悬液浓度为2.5×104个/ml,加入96孔培养板中,每孔加入200 μl,静置培养至细胞接近融合。弃上清,加入无血清DMEM,继续培养24 h,使细胞维持生长静止状态。分别加入0,10-9,10-8,10-7,10-6mol/L AVP和10-7mol/L AVP+10-7mol/L [d(CH2)5Tyr2(Me)]AVP。培养48h后加入3H-脯氨酸92.5 MBq/L和维生素C 50 mg/L, 4 h后用2.5 g/L胰蛋白酶消化细胞呈细胞悬液,多头细胞收集器收集细胞至玻璃纤维滤纸上,烤干。将玻璃纤维滤纸置于闪烁计数管中,每管加入闪烁液0.5 ml,用液态闪烁计数仪测定放射性。
1.4CFs培养上清胶原含量的测定以羟脯氨酸比色法测定CFs培养上清胶原含量[8]。将对数生长期的CFs用2.5 g/L胰蛋白酶消化,用含100 ml/L胎牛血清的DMEM培养液调整细胞浓度为2.5×104个/ml,加入96孔培养板,每孔200 μl,静置培养至细胞接近融合。加入条件培养液干预同1.3。48 h后吸取培养上清50 μl,加入玻璃试管中,100℃烤干。加入50 μl 4 mol/L NaOH,轻轻震荡,在沸水中煮90 min,加入50 μl柠檬酸使pH值达6.0。加入1.0 ml氯氨T溶液,室温静置20 min。加入1.0 ml醛-过氯酸溶液,65℃水浴15 min,分光光度计在550 nm测定光吸收值A。
2结果
2.1AVP对CFs 3H-脯氨酸掺入的影响10-9,10-8 mol/L AVP组CFs 3H-脯氨酸掺入率分别为184±59,276±63 cpm/5000 cells,与对照组166±31 cpm/5000 cells无统计学差别(均P>0.05),10-7,10-6mol/L AVP组3H-脯氨酸掺入率分别为541±96,565±72 cpm/5000 cells,明显高于对照组(均P<0.01)。10-7mol/L[d(CH2)5Tyr2(Me)]AVP+10-7mol/L AVP组3H-脯氨酸掺入率为268±64 cpm/5000 cells,显著低于10-7mol/L AVP组(P<0.01, 图1)。
2.2AVP对CFs培养上清胶原含量的影响10-9,10-8 mol/L AVP组CFs培养上清A值分别为0.20±0.01和0.21±0.01,与对照组0.19±0.01比较无显著差异(均P>0.05)。10-7,10-6mol/L AVP组分别为0.22±0.01和0.24±0.01,明显高于对照组(均P<0.01)。10-7mol/L [d(CH2)5Tyr2(Me)]AVP+10-7mol/L AVP组CFs培养上清A值为0.19±0.01,明显低于 10-7mol/L AVP组(P<0.01,图2)。
图 1[d(CH2)5
