Lew R A, Baertschi A J
Department of Physiology, University of Virginia, Charlottesville 22908.
Am J Physiol. 1992 Oct;263(4 Pt 2):H1071-7. doi: 10.1152/ajpheart.1992.263.4.H1071.
Coculture of endothelial cells with atrial cells (R. A. Lew and A. J. Baertschi. Biochem. Biophys. Res. Commun. 163: 701-709, 1989) increased atrial natriuretic factor (ANF) release to 205 +/- 15% (n = 33 experiments) of basal secretion (2.02 +/- 0.33 ng/ml). Stimulation of ANF release by endothelial cells was significantly reduced (P < 0.05) by addition of the calcium channel antagonist nicardipine (Nic, 100 nM; by 69 +/- 4%), the guanylate cyclase activator sodium nitroprusside (SNP, 1 microM; by 97 +/- 27%), or acetylcholine (ACh, 10 microM; by 55 +/- 13%). Endothelial cell-conditioned medium elicited a 62 +/- 10% (n = 10) increase in ANF release. Rat and porcine endothelin (0.1-100 nM) each elicited a dose-dependent increase in ANF release [up to 84 +/- 14% (n = 18) over baseline]. The activity of conditioned medium was not affected by heat or trypsin treatment, but was significantly reduced by addition of Nic or SNP and was attenuated by ACh. Stimulation of ANF by 1 nM synthetic rat or porcine endothelin was also unaffected by heat or trypsin but was significantly reduced by Nic, SNP, and ACh. Addition of endothelin-specific antiserum abolished the ANF stimulatory activity of endothelial cell-conditioned medium. Neither inhibition of superoxide anion by superoxide dismutase nor inhibition of endothelium-derived nitric oxide production by NG-monomethyl-L-arginine affected the ANF release from coculture. Thus endothelial cells release a heat-stable, diffusible ANF stimulatory factor, which is not endothelium-derived relaxing factor or superoxide anion but is biologically and immunologically similar to endothelin.
内皮细胞与心房细胞共培养（R. A. 卢和A. J. 贝尔奇。《生物化学与生物物理研究通讯》163: 701 - 709, 1989）使心房利钠因子（ANF）释放增加至基础分泌量（2.02 ± 0.33 ng/ml）的205 ± 15%（n = 33次实验）。添加钙通道拮抗剂尼卡地平（Nic，100 nM；降低69 ± 4%）、鸟苷酸环化酶激活剂硝普钠（SNP，1 μM；降低97 ± 27%）或乙酰胆碱（ACh，10 μM；降低55 ± 13%）后，内皮细胞对ANF释放的刺激作用显著降低（P < 0.05）。内皮细胞条件培养基使ANF释放增加62 ± 10%（n = 10）。大鼠和猪内皮素（0.1 - 100 nM）均引起ANF释放呈剂量依赖性增加[最高比基线增加84 ± 14%（n = 18）]。条件培养基的活性不受加热或胰蛋白酶处理的影响，但添加Nic或SNP可使其显著降低，ACh可使其减弱。1 nM合成大鼠或猪内皮素对ANF的刺激作用也不受加热或胰蛋白酶的影响，但Nic、SNP和ACh可使其显著降低。添加内皮素特异性抗血清可消除内皮细胞条件培养基的ANF刺激活性。超氧化物歧化酶对超氧阴离子的抑制或N G - 单甲基 - L - 精氨酸对内皮源性一氧化氮生成的抑制均不影响共培养体系中ANF的释放。因此，内皮细胞释放一种热稳定、可扩散的ANF刺激因子，它不是内皮源性舒张因子或超氧阴离子，但在生物学和免疫学上与内皮素相似。
