大鼠耐力训练增加血红素加氧酶1诱导的血管舒张

目的 观察大鼠急性耐力训练运动后血管收缩及舒张功能的变化并探讨其机制.方法 健康雄性SD大鼠在运动平板上进行跑步适应性训练2周后,进行一周耐力训练.训练方式为平板跑,运动5 d/周,耐力训练时平均运动距离2000～2300 m/d.同年龄安静饲养动物为对照.运动结束时取降主动脉在体外检测血管对80 mmol/L高钾溶液与1 μmol/L苯肾上腺素的收缩反应,以及血管对乙酰胆碱的舒张反应.阻断一氧化氮合酶(NOS)及血红素加氧酶1(HO-1)后再次观察血管对乙酰胆碱的舒张反应.部分主动脉环进行免疫组织化学检测血管内皮HO-1.同年龄静止饲养大鼠作为对照.结果 大鼠经1周耐力运动训练后,主动脉对高钾溶液的收缩反应未见明显变化,对苯肾上腺素引起的收缩反应显著减弱,对乙酰胆碱的舒张反应显著增强(P＜0.01).NOS阻断剂预孵后,正常不运动对照大鼠血管内皮依赖性舒张被阻断达(97.7±3.3)%,经过耐力训练的大鼠血管被阻断(78.8±2.1)%(与对照组比较,P＜0.01),耐力训练组尚存的内皮依赖性舒张可被HO-1阻断剂protoporphyrin Ⅸ Zinc(Ⅱ)进一步阻断.免疫组化结果显示主动脉血管HO-1显著增加.结论 急性耐力运动训练后血管内皮依赖性舒张功能增强,该作用可能与运动诱导的血管内皮中HO-1增加有关.     

运动对胰岛素抵抗大鼠内皮依赖性血管舒张功能干预效应的研究

目的　探讨运动对高脂膳食诱导胰岛素抵抗 (IR)大鼠内皮依赖性血管舒张功能(EDVR)的干预效应及其发生机制。　方法　特殊高脂膳食喂养 4周 ,建立 IR动物模型。游泳运动前后以钳夹技术观察 IR大鼠胰岛素敏感性、大鼠离体主动脉条对乙酰胆碱 (Ach)依赖性血管舒张功能的反应及其大鼠主动脉的一氧化氮合成酶 -一氧化氮 -环岛苷酸 (NOS- NO- c GMP)环功能状态。　结果　 (1 )运动后 IR大鼠葡萄糖输注率 (GIR)显著高于非运动 IR大鼠 (P<0 .0 5 ) ,正常大鼠运动前后GIR水平无明显变化。(2 ) IR大鼠运动后离体主动脉条对 Ach依赖性血管舒张功能反应显著改善 ,最大舒张反应升高达 1 9.4 3% (P<0 .0 1 ) ,正常大鼠运动后离体主动脉条对 Ach依赖性血管舒张功能反应也明显改善 ,最大舒张反应升高达 1 4 .78% (P<0 .0 5 )。 (3) IR大鼠运动后主动脉 NO及 c GMP水平增加 (P<0 .0 5 )。大鼠主动脉条对 Ach依赖性血管舒张反应与 NO浓度呈显著负相关 (r=- 0 .6 4 9,P<0 .0 5 )。　结论　运动能改善 IR大鼠胰岛素敏感性及内皮依赖性血管舒张功能 ,运动可增加 IR大鼠主动脉 NO及 c GMP水平 ,提示运动是一个从改善血管内皮功能入手 ,干预治疗 IR的新举措     

肾血管性高血压大鼠血管内皮细胞功能的变化

目的观察肾血管性高血压(RVH)大鼠血管内皮细胞功能的变化并探讨其机制。方法体重为160~180g健康雄性Wistar大鼠随机分成2组高血压模型(RVH)组及对照(C)组。术后4周,用颈动脉直接插管法测定大鼠血压,应用生物测定法观察大鼠离体主动脉舒缩反应及美蓝(MB)、L-NAME、硝普钠(SNP)、左旋精氨酸(L-Arg)对其的影响。结果RVH大鼠离体胸主动脉环对苯肾上腺素(PHE)引起的收缩反应比对照组明显增高,去除内皮后可消除两组差异。鸟苷酸环化酶抑制剂美蓝及NO合成酶抑制剂L-NAME可使对照组收缩反应增加较RVH组明显。RVH大鼠胸主动脉环由乙酰胆碱(Ach)引起的内皮依赖性舒张反应较对照组明显减弱,而对非内皮依赖性松弛剂硝普钠(SNP)的舒张反应两组间无显著差异。NO合成底物L-Arg能显著提高RVH大鼠内皮依赖性舒张反应。结论肾血管性高血压血管内皮依赖的收缩反应增强,舒张反应减弱。其机制是血管内皮产生和释放EDRF(NO)功能受损和(或)EDRF作用减弱,合成NO的底物L-Arg不足。     

肾血管性高血压大鼠血管内皮细胞功能的变化

目的观察肾血管性高血压(RVH)大鼠血管内皮细胞功能的变化并探讨其机制.方法体重为160～180 g健康雄性Wistar大鼠随机分成2组:高血压模型(RVH)组及对照(C)组.术后4周,用颈动脉直接插管法测定大鼠血压,应用生物测定法观察大鼠离体主动脉舒缩反应及美蓝(MB)、L-NAME、硝普钠(SNP)、左旋精氨酸(L-Arg)对其的影响.结果 RVH大鼠离体胸主动脉环对苯肾上腺素(PHE)引起的收缩反应比对照组明显增高,去除内皮后可消除两组差异.鸟苷酸环化酶抑制剂美蓝及NO合成酶抑制剂L-NAME可使对照组收缩反应增加较RVH组明显.RVH大鼠胸主动脉环由乙酰胆碱(Ach)引起的内皮依赖性舒张反应较对照组明显减弱,而对非内皮依赖性松弛剂硝普钠(SNP)的舒张反应两组间无显著差异.NO合成底物L-Arg能显著提高RVH大鼠内皮依赖性舒张反应.结论肾血管性高血压血管内皮依赖的收缩反应增强,舒张反应减弱.其机制是血管内皮产生和释放EDRF(NO)功能受损和(或)EDRF作用减弱,合成NO的底物L-Arg不足.     

奥美沙坦酯干预对急性心肌梗死大鼠血管内皮功能的影响

目的 探讨奥美沙坦酯对大鼠急性心肌梗死(AMI)后血管内皮功能的干预效应.方法 结扎SD大鼠左冠状动脉前降支制作AMI模型,共33只,将术后24 h存活的24只大鼠随机分为单纯AMI组、奥美沙坦酯1 mg·kg-1·d-1组(奥美沙坦酯Ⅰ组)和奥美沙坦酯3 mg·kg-1·d-1组(奥美沙坦酯Ⅱ组),每组8只,另设假手术组7只为对照组.术后20～24 h内起灌胃给药,AMI组和假手术组灌以等体积助溶剂(0.5%羧甲基纤维素钠),喂养2周,离体做胸主动脉条片对去氧肾上腺素的收缩反应、对乙酰胆碱和硝普钠的舒张反应.结果 与假手术组比较,AMI组胸主动脉条片对乙酰胆碱的内皮依赖性舒张反应显著降低,分别为(6.15±0.03)×10-8mol/L和(4.45±0.21)×10-7 mol/L(P＜0.05).奥美沙坦酯干预后,胸主动脉内皮依赖性舒张改善,其奥美沙坦酯Ⅰ、奥美沙坦酯Ⅱ组分别为(2.65±0.12)×10-7 mol/L和(1.66±1.0)×10-7mol/L,与AMI组比较,差异有统计学意义(P＜0.05).而各组对去氧肾上腺素的收缩反应和对硝普钠的非内皮依赖性舒张反应比较,差异无统计学意义(均为P＞0.05).结论 大鼠AMI后2周即出现显著内皮依赖性舒张功能减退,早期应用奥美沙坦酯干预能显著改善该紊乱的内皮功能.     

老年大鼠主动脉内皮依赖性舒张反应的研究

为探讨血管老化对血管内皮依赖性舒张反应的影响,本实验观察了离体青年和老年大鼠主动脉对乙酰胆碱(ACh)和硝普钠(SNP)的舒张反应及血管组织环化-磷酸鸟苷(cGMP)含量的变化。结果发现,老年大鼠主动脉对ACh的内皮依赖性舒张反应减弱(P<0.01),而对SNP的非内应依赖性舒张反应无明显受损;老年大鼠主动脉组织的基础cGMP含量和ACh刺激后的cGMP含量均低于青年大鼠(P<0.01)。提示血管老化引起的内皮依赖性舒张反应减弱可能与内皮功能不全、内皮衍生的舒张因子生成或释放减少有关。     

自发性高血压大鼠主动脉血管功能的变化

目的探讨自发性高血压大鼠(SHR)血管舒缩功能变化及其可能机制.方法以32周龄SHR大鼠(n=7)为研究对象,年龄、性别配对的WKY(n=7)大鼠作对照组.观察离体胸主动脉环对不同血管活性物质的舒缩反应.结果 SHR主动脉环对乙酰胆碱(ACh)诱导的内皮依赖性舒张反应明显减弱;对ACh的内皮依赖性收缩反应明显高于WKY.L-NAME加强ACh的收缩作用;对硝普钠(SNP)的收缩反应在两组间无差别.结论 SHR大鼠存在内皮功能障碍,表现为内皮依赖性舒张作用减弱,其机制与内皮合成NO减少及内皮依赖性收缩作用增强有关.     

内皮剥脱后家兔胸主动脉舒张反应的变化

本实验在家兔胸主动脉内皮剥脱模型上，观察血管舒张反应的变化及其与血管平滑肌细胞增殖的关系。结果发现．内皮剥脱后血管对乙酰胆碱的内皮依赖性舒张反应明显降低。术后２周和４周时分别为对照组的２７．７±９．９％和５１．１±１１．４％；实验组和对照组血管对去甲肾上腺素的收缩反应和硝普钠的舒张反应均无显著性差异。内皮剥脱后血管平滑肌细胞显著增殖，内膜增厚。这些结果提示，内皮剥脱后血管的内皮依赖性舒张功能受损，内皮源性舒张因子产生可能减少；血管平滑肌细胞增殖可能与这些变化有关．     

U50,488H对高脂大鼠血管内皮功能的影响

目的 探讨κ-阿片受体（κ-OR）选择性激动剂U50,488H对高脂大鼠血管内皮功能的影响及其机制。方法 成年SD大鼠分别饲以正常和高脂饲料14周,腹腔隔日注射U50,488H和κ-OR阻断剂nor-BNI,麻醉后下腔静脉取血,检测总胆固醇（TC）及低密度脂蛋白（LDL）的水平。透射电子显微镜观察动脉内皮细胞和平滑肌细胞的超微结构改变。观察胸主动脉对内皮依赖性血管舒张剂乙酰胆碱（ACh）及内皮非依赖性血管舒张剂（SNAP）的舒张反应。结果 高脂饲料喂养可引起大鼠血清TC和LDL显著升高;主动脉血管内皮依赖性舒张功能显著降低。透射电镜下可见动脉内皮细胞和平滑肌细胞的超微结构出现损伤。U50,488H可显著减轻高脂血症引起的血管内皮依赖性舒张功能障碍和动脉内皮细胞与平滑肌细胞超微结构损伤,κ-OR阻断剂nor-BNI可以阻断U50,488H的上述作用。结论 高脂血症大鼠存在内皮功能障碍,U50,488H可通过激活κ-OR改善高脂血症导致的内皮结构改变和功能障碍。     

自发性高血压大鼠主动脉血管功能的变化

目的 探讨自发性高血压大鼠(SHR)血管舒缩功能变化及其可能机制。方法 以32周龄级极大鼠(n＝7)为研究对象，年龄、性别配对的wKY(n＝7)大鼠作对照组。观察离体胸主动脉环对不同血管活性物质的舒缩反应。结果 SHR主动脉环对乙酰胆碱(ACh)诱导的内皮依赖性舒张反应明显减弱；对ACh的内皮依赖性收缩反应明显高于wKY。L-NAME加强ACh的收缩作用；对硝普钠(SNP)的收缩反应在两组间无差别。结论 SHR大鼠存在内皮功能障碍，表现为内皮依赖性舒张作用减弱，其机制与内皮合成NO减少及内皮依赖性收缩作用增强有关。     

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.     

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.     

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.     

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.