Lowering of kininogen in rat blood by catecholamines

Summary Catecholamines lower the kininogen content of rat blood in vivo and in vitro. Blood cells are required: these are neither erythrocytes, lymphocytes, eosinophils nor platelets but could be neutrophils or basophils.The bovine protease inhibitor (Trasylol^®) inhibits the effects of l-adrenaline in vivo and in vitro but fails to affect the action of cellulose sulfate on rat plasma kininogen by more than a small extent.     

HKD5对人脐静脉内皮细胞游走及血管形成的抑制作用

目的:体外实验研究活化型高分子量激肽原（HKa）轻链富含组氨酸区域5 (HKD5)对人脐静脉内皮细胞（HUVECs）的粘附、游走及血管形成的影响。 方法:体外重组融合蛋白-活化型高分子量激肽原轻链富含组氨酸区域5 (GST-D5H)。WST-1法观察HUVECs细胞粘附能力；用改良Boyden Chamber膜侵袭系统观察HUVECs细胞游走(趋化)；用血管形成实验观察HUVECs细胞形成新生血管能力。 结果:GST-D5H作用后，HUVECs细胞粘贴率降低（P<0.05），游走穿膜细胞数明显低于对照组（P<0.01），诱导内皮细胞形成管腔数及长度均低于对照组（P<0.05）。 结论:GST-D5H能有效抑制HUVECs细胞粘附、游走，使该细胞粘附力降低，迁移性下降及血管形成数目减少或变细。     

Acute pulmonary edema and plasma kininogen consumption in the adrenaline-treated rat: Inhibition by acetylsalicylic acid and resistance to salicylate and indomethacin

Summary Pulmonary edema and plasma kininogen consumption caused by intravenously administered adrenaline, were inhibited in rats pretreated with acetylsalicylic acid, but not in rats pretreated with indomethacin or sodium salicylate. The possibility of a connection between this edema and mast cell-linked activation of kallikrein by adrenaline is discussed, as well as the possible role of acetylsalicylic acid acting as an acetylating inhibitor of these processes.     

Weitere Untersuchungen zur Existenz zweier kininbildender Systeme in menschlichem Plasma

Zusammenfassung In menschlichem Plasma werden zwei kininbildende Enzyme und zwei Kininogene nachgewiesen. Kininogenase II, durch Glaskontakt aktiviert, greift nur Kininogen II an. Kininogenase I, durch Säurebehandlung aktiviert und mit Serumkallikrein identisch, wirkt bevorzugt auf Kininogen I ein. Möglicherweise greift sie aber auch das Substrat II an.Die Darstellung von Kininogenase I- und II- sowie Kininogen I- und II-Präparaten aus menschlichem Plasma wird beschrieben.Während des Kontaktes von menschlichem Plasma mit Glas wird nicht nur das System II, sondern auch I aktiviert. Kininogenase I wird aber anschließend inaktiviert, noch bevor ihr Substrat umgesetzt ist. Die Inaktivierung kann durch Säurebehandlung nicht rückgängig gemacht werden.     

Effect of dihydralazine on the renal kallikrein-kinin system of the rat

Dihydralazine (0.1 mg/kg), injected intravenously into male Sprague-Dawley rats, caused a decrease in mean arterial blood pressure and an increase in renal plasma flow, while urine volume remained unchanged. Dihydralazine had no effect on kallikrein excretion in the urine and on kallikrein activity in the renal cortex. No correlation was found between renal kallikrein and either renal plasma flow or mean arterial blood pressure. The excretion of kinins in the urine rose markedly after the administration of dihydralazine; no correlation between urinary kinins and urinary or renal kallikrein was observed. Dihydralazine had no influence on the kininogen content of blood-free renal cortex. The enzymatic activity of kininase II in renal cortex was not impaired by dihydralazine. It is suggested that the increased formation of kinins within the kidney could be involved in the vasodilating and blood pressure lowering effect of dihydralazine.     

Angiotensinogen and Kininogen: Cloning and Sequence Analysis of the Cdnas

The primary structures of the angiotensinogen precursor and the low molecular weight (LMW) kininogen precursors have been deduced by determining the nucleotide sequences of cloned DNAs complementary to their mRNAs. The angiotensinogen precursor consists of a mature angiotensinogen of 453 amino acid residues and a putative signal peptide of 24 amino acid residues. An angiotensin moiety is located at the amino-terminal part of angiotensinogen, preceded directly by the signal peptide and followed by a large carboxyI-terminal sequence that contains two internally homologous sequences and three potential glycosylation sites. The LMW kininogen precursors are encoded by two very similar but distinct mRNAs and composed of 436 and 434 amino acid residues. Both kininogens contain two internally homologous sequences in which all amino acid differences between the two kininogens are located. This suggests that these homologous regions may be biologically significant in relation to the existence of two LMW kininogens.     

Cleaved high molecular weight kininogen, a novel factor in the regulation of matrix metalloproteinases in vascular smooth muscle cells

We previously reported that Brown Norway Katholiek rats, which feature a deficiency of plasma kininogens, develop severe abdominal aortic aneurysm. Increased activity of matrix metalloproteinases (MMPs) in the aortic wall, leading to degradation of extracellular matrix components, is considered to play a crucial role in aneurysm formation. Using an in vitro model of vascular smooth muscle cells (VSMCs), cultured from the rat aorta, we investigated whether the cleaved form of high molecular weight kininogen, designated HKa, affects the expression of MMP-9 and MMP-2 and their tissue inhibitors (TIMPs). Treatment of VSMCs with HKa reduced in a concentration-dependent manner IL-1α-induced release of MMP-9 and MMP-2, associated with decreased MMP enzymatic activity levels in conditioned media, as demonstrated by gelatin zymography and fluorescein-labeled gelatin substrate assay, respectively. Real-time PCR revealed that HKa reduced corresponding MMP-9 mRNA levels. Further investigations showed that this effect did not result from a modified rate of MMP-9 mRNA degradation. TIMP-1 mRNA levels, already increased as a result of cytokine-stimulation, were significantly enhanced by HKa. Furthermore, we found elevated basal mRNA expression levels of MMP-2 and TIMP-2 in VSMCs derived from kininogen-deficient Brown Norway Katholiek rats. These results demonstrate for the first time that HKa affects the regulation of MMPs in VSMCs.     

Kininogen D5和TRAIL融合蛋白的克隆表达及生物学活性的研究

用重组PCR技术得到Kininogen D5和TRAIL的融合编码序列,将该DNA片段克隆到原核表达载体pMAL-c2,重组质粒转化大肠杆菌BL21,IPTG诱导蛋白表达,得到MBP-KT和MBP-TK,经AmyloseResin亲和层析柱层析,得到初步纯化的融合蛋白.结果表明MBP-KT对胰腺癌细胞1990有明显的杀伤作用其作用的ED5.为20 ng/ml,而MBP-TK对1990的抑制作用不明显;同时,MBP-KT和MBP-KD5对内皮细胞ECV304有明显的抑制作用,MBP/KT作用于ECV304的ED50为0.1μg/ml,MBP/KD5作用于ECV304的ED50为9.5μg/ml,但是MBP-TK和TRAIL几乎无作用,表明融合蛋白KT既具抗肿瘤作用又有抗新生血管的作用.本研究为进一步开发靶向性杀伤肿瘤药物奠定了基础.     

组织激肽释放酶、激肽原在子痫前期患者胎盘中表达的研究

目的:研究胎盘中组织激肽释放酶、激肽原表达水平,探讨组织激肽释放酶-激肽系统在子痫前期发病中的作用。方法:采集子痫前期患者(轻度9例,重度11例)及正常妊娠妇女的新鲜胎盘标本各20例。用酶免疫分析法检测胎盘中活化型组织激肽释放酶水平,用免疫组化技术对各组胎盘中激肽原表达进行定位、定量分析。结果:子痫前期患者胎盘中活化型组织激肽释放酶水平为(2.40±0.88)×10-4ku/mg,显著低于正常妊娠妇女的(3.61±1.25)×10-4ku/mg(P<0.01),激肽原于胎盘绒毛间隙毛细血管内皮细胞表面表达,子痫前期患者胎盘组织的表达阳性率显著低于正常妊娠妇女(P<0.05),而子痫前期轻度组与重度组之间组织激肽释放酶和激肽原的表达均无显著性差异(P>0.05;P>0.05)。结论:胎盘组织激肽释放酶、激肽原低表达可能是子痫前期发生的重要原因。