花生四烯酸的细胞色素P450酶代谢在高血压研究中的进展

花生四烯酸(AA)在体内含量丰富,其代谢产物具有重要的生理和病理作用.目前已知,花生四烯酸在受体依赖的PLA2激活后由细胞膜释放,可经过三条途径进行代谢:一是环氧化酶途径,终产物有前列腺素(prostaglandin)、前列环素(prostacyclin,PGI2)和血栓素A2(thrombixaneA2,TXA2);二是脂氧化酶途径,形成HPETES(hydroperoxyeicosatetraenoic acids)、HETES(hydroxyeicosatetraenoic acids)和leukotrienes等;第三就是细胞色素P450酶(CYP)途径,花生四烯酸经此途径的代谢也有三种方式,(1)丙烯氧化反应,生成5-,8-,9-,11-,12-,15-HETE,其中除12(R)-HETE外,其它也可以经脂氧化酶途径产生,(2)表氧化反应,主要由血管内皮细胞生成EETs(epoxyeicosatrienoic acid),包括5,6-,8,9-,11,12-和14,15-EET及其下级产物DHETs(dihydroxyeicosatetraenoic acids),(3)ω-和ω-1-羟化反应,生成20-和19-HETE[1].     

细胞色素P450表氧化酶经线粒体途径抗内皮细胞凋亡的机制研究

目的:研究细胞色素P450表氧化酶对肿瘤坏死因子诱导的内皮细胞抗凋亡的机制。方法:原代培养主动脉内皮细胞(BAECs)2周后,分别转染细胞色素P450表氧化酶基因rAAV-F87V。用肿瘤坏死因子(TNF-α)和放线菌素D(ActD)诱导凋亡,用Western blot法分别检测细胞胞质及线粒体的细胞色素C的含量。以ELISA方法检测Caspase-3、-8、-9的活性。结果:Western Blot结果表明,转染CYP P450表氧化酶后细胞胞质的细胞色素C明显减少,线粒体的细胞色素C明显增加。ELISA结果显示Caspase-3、-8、-9的活性均较对照组明显降低(均P0.05)。结论:细胞色素P450表氧化酶基因rAAV-F87V抑制内皮细胞凋亡是通过抑制线粒体途径发挥作用的。     

细胞色素P450表氧化酶通过PI3K/AKT及ERK/MAPK途径抗内皮细胞凋亡的机制

目的:研究细胞色素P450表氧化酶对肿瘤坏死因子(TNF)-α诱导内皮细胞抗凋亡的机制。方法:在原代培养的牛主动脉内皮细胞(BAECs)中,分别转染细胞色素P450表氧化酶基因rAAV-F87V2周,证实其在内皮细胞中高效表达。用TNF-α(10ng/ml)和放线菌素D(ActD)(5ng/ml)诱导凋亡,流式细胞计数观察其凋亡变化,用Western blot法检测蛋白激酶B(AKT)及细胞外信号调节蛋白激酶(ERK)的磷酸化水平,用流式细胞计数的方法观察空白组及转染F87V组加入AKT抑制剂、LY294002、芹菜素及PD98059后的细胞凋亡比例。结果:与对照组比较,转染细胞色素P450表氧化酶基因后BAECs能高效表达P450表氧化酶基因F87V(P<0.05);流式计数凋亡细胞数,转染表氧化酶较对照组明显减少(P<0.05);转染CYP P450表氧化酶后,AKT及ERK的磷酸化增加;磷脂酰肌醇3激酶(PI3K)、丝裂原活化蛋白激酶(MAPK)和MKK的抑制剂后转染F87V组较对照组凋亡细胞比例明显减少(P<0.05)。结论:细胞色素P450表氧化酶基因rAAV-F87V能通过MAPK(ERK1/2)与PI3K/AKT途径发挥抗凋亡作用。     

高效液相色谱法测定15-羟化二十烷四烯酸

近年来的研究表明,在脑、肾、肺、血管等组织中,花生四烯酸(AA)可以被细胞色素P450(CYP450)或15脂氧化酶代谢为15-羟化二十烷四烯酸(15- HETE)、20-羟化二十烷四烯酸(20- HETE)、环氧二十碳四烯酸(EETs)等多种生物活性物质。最近研究证明,15- HETE与许多疾病如骨组织、血管疾病的发生发展有关。鉴于15-HETE在体     

花生四烯酸细胞色素P450表氧化酶在自发性高血压大鼠血压的调节中的作用

背景与目的花生四烯酸细胞色素P450（CYP）表氧化酶代谢花生四烯酸产生表氧化廿烷酸（EETs），又称为内皮源性超极化因子（EDHFs），在局部微循环的调节中起着重要作用。然而EETs在血压的调节中是否起作用还不清楚。本研究通过对成年自发性高血压大鼠导入花生四烯酸细胞色素表氧化酶基因来观察其血压变化，从而进一步明确EETs在血压调节中的作用。方法：将含人类细胞色素P450表氧化酶CYP2J2 cDNA的真核细胞表达质粒pcDNA．2J2经静脉注射（3mg／kg）人雄性成年自发性高血压大鼠，并以pcDNA3．1对照。然后用尾部血压计测量血压。并在注射后3周和4周时处死动物，检测CYP2J2在不同组织中的表达情况。结果：注射质粒后对照组血压一直无显著性变化，而pcDNA．2J2治疗组大鼠血压显著降低（P〈0．05），这一降压效应持续两周以上。Western blotting显示在实验组动物肺、肝和肾的总蛋白中通过特异性抗-CYP2J2抗体可检测出显著量的人类CYP2J2蛋白的表达。结论：本实验显示对成年自发性高血压大鼠导人人类CYP2J2基因，使CYP2J2可以在动物组织中高表达，从而引起相对持久的降压作用，这些结果提示花生四烯酸细胞色素P450表氧化酶通过产生EDHFs参与了动物血压的调节作用。     

细胞色素P450表氧化酶对内皮细胞凋亡及NF—κB表达的影响

目的研究细胞色素P450表氧化酶对肿瘤坏死因子诱导的内皮细胞凋亡及NF-KB活性的影响。方法在原代培养的牛主动脉内皮细胞中，分别转染细胞色素P450表氧化酶基因rAAV-2J2，rAAV-2C11，rAAV—F87V两周后，用肿瘤坏死因子（TNF-d）（10ng／ml）和放线菌素D（ActD）（5ng／ml）诱导凋亡，通过DNA ladder观察细胞凋亡，同时ELISA法测定NF-κB的活性。结果与对照组相比，转染细胞色素P450表氧化酶基因后能抑制内皮细胞的凋亡，同时诱导细胞凋亡后，转染CYP450各基因组NF-KB中P65的活性较对照组明显降低。结论细胞色素P450表氧化酶能明显的抑制肿瘤坏死因子诱导的内皮细胞凋亡，并通过抑制NF-κB的核转位发挥抗凋亡作用。     

花生四烯酸细胞色素P450表氧化酶代谢产物环氧二十碳三烯酸生物学作用

对于花生四烯酸经细胞色素P450表氧化酶作用生成的环氧二十碳三烯酸(EETs),最初在心血管及肾脏系统中被广泛研究,并发现EETs的舒张血管、抑制血小板的聚集、抑制血管平滑肌细胞的炎症反应及平滑肌细胞的迁移、增强纤维蛋白的溶解等作用,为预防及治疗许多心血管疾病如高血压、动脉粥样硬化等提供了新的研究方向。近来研究发现EETs具有促进机体肿瘤细胞的增殖、迁移等作用,其有可能使EET成为肿瘤治疗的新靶点。深入研究EETs的生物学作用及其作用机制,将为临床治疗某些疾病提供新的思路。     

花生四烯酸细胞色素P450表氧化酶代谢产物环氧二十碳三烯酸生物学作用

对于花生四烯酸经细胞色素P450表氧化酶作用生成的环氧二十碳三烯酸（EETs）,最初在心血管及肾脏系统中被广泛研究,并发现EETs的舒张血管、抑制血小板的聚集、抑制血管平滑肌细胞的炎症反应及平滑肌细胞的迁移、增强纤维蛋白的溶解等作用,为预防及治疗许多心血管疾病如高血压、动脉粥样硬化等提供了新的研究方向。近来研究发现EETs具有促进机体肿瘤细胞的增殖、迁移等作用,其有可能使EET成为肿瘤治疗的新靶点。深入研究EETs的生物学作用及其作用机制,将为临床治疗某些疾病提供新的思路。     

EETs的心血管效应及心肌保护

研究表明,环氧-二十碳三烯酸(EETs)是花生四烯酸经细胞色素P450氧化代谢途径的产物之一,可作用于多种心血管细胞的离子通道,具有强大的心血管效应,本文就其心血管效应及心肌保护的意义作一综述.     

EETs的心血管效应及心肌保护

研究表明，环氧-二十碳三烯酸(EETs)是花生四烯酸经细胞色素P450氧化代谢途径的产物之一，可作用于多种心血管细胞的离子通道，具有强大的心血管效应，本文就其心血管效应及心肌保护的意义作一综述。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.