CCK-8对内毒素休克大鼠肺脏细胞因子的抑制效应

观察八肽胆囊收缩素(cholecystokinin-octapeptide,CCK-8）改善脂多糖(lipopolysaccharide,LPS）引起的大鼠内毒素性休克（endotoxic shock,ES）过程中血清及肺脏细胞因子的变化,探讨p38比裂素活化蛋白激酶（p38 mito-gen-activated protein kinase,p38 MAPK）的信号转导作用。用生理多道记录仪观察尾静脉注入LPS(p38 mito-gen-activated protein kinase,p38 MAPK）的信号转导作用。用生理多道记录仪观察尾静脉注入 LPS（8mg/kg i.v.）复制的SD大鼠ES模型、LPS注入前10min尾静脉注入CCK-8(40ug/kg i.v.）、单独注入CCK-8(40Uug/kg i.v.）或生理盐水（对照）的四组大鼠平均动脉血压（MAP）的改变,应用ELISA试剂盒检测血清和肺脏中炎性细胞因子（TNF-a、IL-1β和IL-6）的变化。用Western blot检测肺脏p38 MAPK的表达。结果显示：CCK-8可改善LPS引起的大鼠MAP的下降。与对照组相比,LPS可显著增加血清和肺脏TNF-a、IL-1β和IL-6含量;CCK-8可显著抑制LPS诱导的血清和肺脏TNF-a、IL-1β和IL-6的增加。CCK-8可增加ES大鼠肺脏磷酸化p38 MAPK的表达。结果提示CCK-8可改善ES大鼠MAP的降低,并对肺脏促炎性细胞因子过量产生有抑制作用,p38MAPK可能参与了其信号转导机制。     

外源性硫化氢对家兔内毒素休克诱发肺动脉高压的干预作用*

目的: 探讨外源性硫化氢(H₂S)对家兔内毒素休克(ES)诱发肺动脉血管反应性的影响。方法: 本实验采用家兔经颈静脉注射脂多糖(LPS,8 mg/0.8 ml/kg)复制家兔ES模型,并提前15 min腹腔注射H₂S供体硫氢化钠(NaHS,28 μmol/kg)进行干预。随机将新西兰大耳白家兔分为4组(n=8):溶剂对照组、LPS组、LPS+NaHS组和NaHS组。监测平均动脉压(MAP)和平均肺动脉压(MPAP)的变化;应用血管环张力测定技术,检测各组家兔离体肺动脉张力变化;应用光镜和扫描电镜分别观察肺动脉管壁结构及肺动脉内皮细胞超微结构变化。结果: ①注射LPS后家兔出现MAP降低、MPAP升高,成功复制家兔ES模型;与LPS组相比,LPS+NaHS组家兔MPAP在各个时间点均显著降低(P均﹤0.05);②与正常对照组相比,LPS组家兔肺动脉对苯肾上腺素(PE)的收缩反应增强,对乙酰胆碱(ACh)的舒张反应降低(P均﹤0.01);与LPS组相比,LPS+NaHS组家兔肺动脉对PE的收缩反应降低,而对ACh的舒张反应增强(P均﹤0.05)。③光镜下可见正常对照组家兔血管内皮细胞结构连续,内皮下弹力纤维完整,平滑肌层排列整齐;LPS组家兔部分肺动脉内皮细胞脱落,内皮下弹力纤维断裂,平滑肌层结构紊乱;与LPS组相比,LPS+NaHS组家兔肺动脉壁各层损伤减轻; NaHS组肺动脉壁各层形态结构接近正常对照组。扫描电镜检查发现LPS组家兔肺动脉部分内皮细胞缺失;LPS+NaHS组肺动脉内皮细胞形态接近对照组,仅可见细胞间隙稍增宽,未见细胞脱落。结论: 外源性H₂S可保护肺动脉内皮细胞,调节ES时肺动脉反应性的改变,从而降低ES家兔PAH。     

八肽胆囊收缩素对内毒素休克时海马损伤的影响及其机制初探

目的：观察八肽胆囊收缩素（CCK-8）对内毒素休克（ES）时海马损伤的影响,并探讨其可能的作用机制。方法：将日本大耳白兔经静脉注入内毒素的主要活性成分脂多糖（LPS,8mg／kg）复制ES模型。动物（32只）随机分为对照组、LPS组、CCK-8＋LPS组和非特异性CCK受体拮抗剂丙谷胺（Pro）＋LPS组（n=8）。监测平均动脉压（MAP）的变化,光、电镜观察海马的组织形态学改变,比色法检测海马NOS和SOD活性、N0和MDA含量的改变．用SD大鼠（12只,同上复制模型及分组）以免疫组织化学染色法观察海马iNOS和nNOS表达的变化。结果：与对照组相比,注入LPS后出现MAP显著而持续下降（P〈0．01）;海马部位神经元损伤明显;iNOS和nNOS表达增强,NOS活性、NO和MDA含量显著升高（P〈0．05、P〈0．01和P〈0．01）,SOD活性则降低（P〈0．01）。预先注入CCK-8可明显减轻上述变化,预先注入Pro则加剧以上变化。结论：CCK-8可减轻ES时脑内海马部位的损伤。其机制可能与其抗氧化作用和抑制NO的过量生成有关。     

内源性一氧化氮在内毒素引起的肺动脉高压和肺损伤中的作用

本实验观察了家兔静脉内注入内毒素的主要成分脂多糖(LPS)后平均动脉血压(MAP)、肺动脉压(PAP)及入、出肺血NO含量的变化,并观察了静脉内预注入NO生成抑制剂Nω-硝基-L-精氨酸(L-NNA)及诱生型NO生成抑制剂氨基胍(AG)后PAP和肺损伤的变化.结果观察到:家兔LPS注入后,MAP均明显下降,LPS注入后0.5、1、1.5、2h PAP明显增高(P<0.05).LPS注入后PAP的高峰期(1h)入肺血NO含量明显降低,出肺血NO无明显变化.与对照组相比,LPS注入后3h出肺血NO含量和5h入、出肺血NO含量均明显增多.相关分析表明,兔LPS注入前和LPS注入后1h PAP与入肺血NO含量呈明显的负相关,而LPS注入后 3h和5h两者相关不明显.静脉预注入L-NNA后,LPS处理组的动物PAP明显增高,入、出肺血丙二醛(MDA)含量也明显增高,动物生存率明显降低.肺组织光镜下可见肺萎陷和小血管淤血加重,白细胞明显增加.静脉预注入AG后,LPS处理组的动物MAP在3～5h明显增高,此时PAP无明显改变,但5h时血中MDA含量明显减低,5h时与LPS组相比肺萎陷和小血管淤血减轻,白细胞也明显减少.以上结果提示,内毒素入血后较早期阶段可出现PAP的升高,此时入肺血NO的减少是参与肺动脉压增高(PAH)的机制之一.家兔内毒素进入血后较早期阶段NO对减轻内毒素引起的PAH和肺损伤起重要作用,而较晚的时期当诱生型NO合酶(iNOS)诱生后释放的NO则参与内毒素引起的肺组织炎症反应和肺损伤.     

八肽胆囊收缩素对大鼠心功能的影响及受体机制

为探讨八肽胆囊收缩素 (CCK 8)对麻醉大鼠心功能的影响及受体机制 ,实验监测了左心室收缩压(LVP)、左心室收缩与舒张期内压变化的最大速率 (±LVdp/dtmax)、心率 (HR)和平均动脉压 (MAP)。结果如下 :小剂量CCK 8(0 4 μg/kg)可引起心动过速 ,MAP、LVP和±LVdp/dtmax轻度上升 ;中剂量CCK 8(4 μg/kg)和大剂量CCK 8(4 0 μg/kg)可引起心动过缓 ,MAP、LVP和±LVdp/dtmax显著增加 ;应用CCK 受体 (CCK R)拮抗剂丙谷胺 (1 0mg/kg)抑制以上变化 ;由逆转录 聚合酶链反应 (RT PCR)检测到心肌组织有CCK A受体 (CCK AR)和CCK B受体 (CCK BR)mRNA表达。以上结果提示 :CCK 8可激活心肌组织的CCK R ,引起剂量依赖性的心功能增加和心率改变。     

生理水平的胆囊收缩素可经胆碱能途径促胰酶分泌

Soudah等研究了生理浓度的胆囊收缩素(CCK)引起人胰腺分泌的作用机制。CCK-8在健康人体主要增加胰蛋白酶和脂酶的含量,阿托品可抑制CCK-8(10ng/kg.h)刺激分泌的胰蛋白酶含量的84.0±7.7%和脂酶含量的78.6±9.2%。而CCK-8剂量为40ng/kg.h时,阿托品的这种抑制作用要小得多(对胰蛋白酶和脂酶的     

胆囊收缩素受体拮抗剂加强大鼠的吗啡镇痛和羟甲芬太尼镇痛

已知大鼠脊髓蛛网膜下腔(i.t.)注射CCK-8能拮抗阿片μ受体介导的镇痛作用。本文给大鼠i.t.注射高选择性CCK-A受体拮抗剂devazepide和CCK-B受体拮抗剂L-365260阻断内源性释放的CCK-8,观察对阿片镇痛的影响。i.t.注射100ng devazepide或2.5ng L-365260可显著地增强吗啡镇痛(4mg/kg,sc),两者的剂量效应曲线均为钟形曲线;i.t.注射66ng devazepide或1.25ng L-365260也能显著地增强羟甲芬太尼(专一的阿片μ受体激动剂,OMF)的镇痛作用(32ng,i.t.),剂量效应曲线亦为钟形曲线。这两种CCK受体拮抗剂本身对病阈无影响。 以上结果表明,脊髓内有内源性CCK-8发挥对抗阿片镇痛作用;鉴于devazepide剂量大于L-365260剂量40-50倍,提示CCK-8在脊髓的抗阿片镇痛功能是通过CCK-B受体实现的。     

八肽胆囊收缩素对抗mu和Kappa型受体介导的镇痛作用

以往的资料表明,八肽胆襄收缩素(CCK-8)能对抗阿片镇痛,本实验进一步分析 CCK-8对抗哪一类型阿片受体激动剂的镇痛作用。给大鼠脊髓蛛网膜下腔(I.T.)注射 CCK-8(剂量4ng到1.0μg)既不产生痛敏也不产生镇痛。I.T.注射特异性的μ受体激动剂 PL01710 ng 或 k 受体激动剂 NDA P500 ng 引起的镇痛作用可被注射 CCK-8 4ng 所对抗。而L.T.注射δ受体激动剂 DPDPE(6.5,13.0和26.Oμg)引起的镇痛作用不能被 CCK-8(4ng,40ng I.T.)所对抗。但 CCK-8对抗 PL017和 NDAP 镇痛的作用可被 I.T.CCK 受体拮抗剂 proglumide(3μg)所翻转。以上结果表明,I.T.注射 CCK-8可有效地对抗μ和 k 受体介导的镇痛,并且这种对抗作用是经 CCK 受体介导而实现的。     

NO在CCK—8减轻肿瘤坏死因子诱导兔肺动脉反应性变化中的作用

为探讨八肽胆囊收缩素（CCK－8）缓解内毒素休克时肺动脉高压的作用机制,应用离体血管环张力测定技术及一氧化氮合酶（NOS）检测方法,观察了一氧化氮（NO）在CCK－8减轻肿瘤坏死因子－α（tumor necrosis factor-al-pha,TNF-α）的抑制肺动脉内皮依赖性舒张反应中的作用。结果显示：TNF－α（4000U／ml）孵育2h时,肺动脉对10^-6mol/L苯肾上腺素(phenylephrine,PE）和10^-6mol/L乙酰胆碱（ACh）的收缩反应及内皮依赖性舒张反应均无明显变化。TNF－α孵育7或14h时,肺动脉对10^-6mol/L ACh介导的内皮依赖性舒张反应降低,CCK－8（0.5μg/ml）可逆转TNF－α的上述作用,CCK－8本身对正常肺动脉反应性无明显影响。TNF－α、CCK－8对PE引起的收缩反应无显著影响。L－精氨酸（L－Arg）可使TNF－α7h内皮依赖性舒张作用恢复。氨基胍（AG）不影响各组肺动脉对10^-6mol/L ACh的内皮依赖性舒张反应,而使TNF－α组肺动脉环对10^-6mol/L PE的收缩反应显著增加。L－硝基精氨酸（L－NNA）使各组肺动脉环对10^-6mol/L ACh反应由舒张变为收缩,对10^-6mol/L PE的收缩反应显著增强。检测7h各组NOS活性,TNF－α组、TNF－α＋CCK－8组均较对照组显著增加,CCK－8组与对照组比较无显著差异。上述结果提示,CCK－8可逆转TNF－α对内皮依赖性舒张反应的抑制作用,此作用可能与NO有关。     

家兔中脑导水管周围灰质中注射八肽胆囊收缩素(CCK-8)拮抗吗啡镇痛和电针镇痛

家兔单侧PAG内注射CCK-83ng,能使静脉注射4mg/kg吗啡引起的镇痛作用降低73％或使电针镇痛效果降低67％。在1.5—6.0ng范围内呈量效关系。无硫的CCK-8无此作用。PAG内注射CCK受体拮抗剂proglumide 4μg可翻转CCK-8的抗吗啡镇痛作用。说明PAG部位注射外源性CCK-8可通过CCK受体对抗阿片镇痛。 PAG内注射CCK-8抗血清可显著增强静脉注射2mg/kg吗啡的镇痛效果。PAG内注射CCK抗血清本身也能引起痛阈轻度升高。说明PAG内有内源性的CCK-8发挥紧张性的抗阿片镇痛作用。     

内源性硫化氢在脂多糖引起的肺动脉高压中的作用

为观察硫化氢(hydrogen sulfide,H2s)在脂多糖(1ipopolysaccharide,LPS)引起的肺动脉高压中的作用,应用离体血管环张力测定方法测定肺动脉反应性,采用生物化学方法测定肺动脉组织中H2S产出率和胱硫醚-γ-裂解酶(cystathionine γ-lyase,CSE)活性,定量PCR方法测定肺动脉组织中CSE表达水平.结果如下:(1)与对照组相比,LPS可显著升高肺动脉平均压(mean pulmonary arterial pressure,mPAP)[(1.82±0.29)kPa vs(1.43±0.26)kPa,P<0.01],降低肺动脉组织中H2S产出率[(26.33±7.84)vs(42.92±8.73)pmoFg wet tissue per minute,P<0.01]和ACh诱导的肺动脉内皮依赖性舒张反应[(75.72±7.22)%vs(86.40±4.40)%,P<0.01];(2)NariS可部分逆转上述变化,而PPG加剧上述变化;(3)CSE活性和CSE mRNA表达的变化与H2S产出率的变化相同.结果提示,LPS对内皮依赖性舒张反应的抑制导致肺动脉高压的发生,此作用可能与H2S有关.     

A new simple mouse model for the in vivo evaluation of cholecystokinin (CCK) antagonists: comparative potencies and durations of action of nonpeptide antagonists

A new simple mouse assay for the in vivo evaluation of CCK antagonists which is based upon visual determination of the gastric emptying of a charcoal meal is described. CCK-8 (24 micrograms/kg s.c.) but not various other peptide and nonpeptide agents effectively inhibited gastric emptying in this test system. The effect of CCK-8 was antagonized by established peripheral CCK antagonists but not representative agents of various other pharmacological classes. The rank order of potency of the CCK antagonists were: L-364,718 (ED50 = 0.01 mg/kg, i.v.; 0.04 mg/kg, p.o.) greater than Compound 16 (ED50 = 1.5 mg/kg, i.v.; 2.0 mg/kg p.o.) greater than asperlicin (ED50 = 14.8 mg/kg i.v.) greater than proglumide (ED50 = 184 mg/kg i.v.; 890 mg/kg, p.o.). Duration of action studies based upon ED50 values determined at various time intervals after oral administration showed that L-364,718 and proglumide are considerably longer acting than Compound 16. Asperlicin (ED50 greater than 300 mg/kg, p.o.) was ineffective as a CCK antagonist when administered orally. These data provide the first direct comparisons of the in vivo potencies of current CCK antagonists and demonstrate the utility of a new simple mouse assay for the in vivo characterization of peripheral CCK antagonists.     

The participation of CCK-8-ergic mechanisms in the regulation of emotional behavior in rodents

Effects of CCK-8 receptor agonists caerulein and pentagastrin and CCK-8 receptor antagonist proglumide on exploratory and locomotor activity of mice and rats were studied. Systemic administration of caerulein (500 ng/kg 1 mcg/kg) decreased significantly the exploratory activity of mice in elevated plus-maze. This anxiogenic-like action of caerulein was attenuated by acute pretreatment with proglumide (1 and 15 mg/kg) but not with diazepam (up to 0.75 mg/kg). Proglumide slightly increased the exploratory activity of rats in plus-maze; on the other hand, caerulein and pentagastrin potently decreased the measures of exploration in this test. Caerulein (10-100 mcg/kg) and proglumide (1 and 15 mg/kg) inhibited 3H-pentagastrin binding in mice brain in in vivo experiments. The data obtained indicate that CCK-8-ergic mechanisms in brain play an important role in the generation of anxiety states in rodents.     

家兔中脑导水管周围灰质中注射八肽胆囊收缩素（CCK—8）拮抗吗啡镇痛和...

We have reported that intracerebroventricular (i. c. v.) injection of 1-4 ng of CCK-8 to the rat produced a remarkable antagonistic effect on morphine analgesia. In order to study the species specificity and the site of action, CCK-8 was microinjected into the PAG of the rabbit, and its influence on morphine analgesia and electroacupuncture analgesia was observed. The latency of the escape response (ERL) to radiant heat focused on the snout was measured as an index of the pain threshold. Microinjections were made via cannulae chronically implanted into the PAG. The drug solutions were delivered in a volume of 1 microliter, at a speed of 0.125 microliter/min. The ERL was measured for a period of 60 or 70 minutes at 10 min intervals. 1. CCK-8 administered unilaterally to the PAG of the rabbit at a dose of 3 ng antagonized the analgesia induced by morphine (4 mg/kg, i. v.) by 73% (P less than 0.001), and reduced the analgesic effect of electroacupuncture by 67% (P less than 0.001). These effects were dose-dependent within the range from 1.5 ng to 6.0 ng. The effect of CCK-8 was reversed by CCK receptor blocker proglumide (4 microliters, intra-PAG injection). Unsulfated CCK-8 (CCK-us) had no effect in this regard. These results indicate that in the PAG of the rabbit, exogenously administered CCK-8 was capable of antagonizing opioid analgesia by the activation of CCK receptors. 2. Two groups of rabbits were given with morphine (2 mg/kg, i. v.) and simultaneous injection of CCK-8 antiserum (CCK-AS, 1 microliter) or normal rabbit serum (NRS) into the PAG.(ABSTRACT TRUNCATED AT 250 WORDS)     

Capsaicin-, resiniferatoxin-, and olvanil-induced adrenaline secretions in rats via the vanilloid receptor.

The effects of capsaicin analogs on adrenaline secretion were investigated in rats. Capsaicin (20-100 microg/kg, i.v.) caused biphasic adrenaline secretion. Capsazepine (20 mg/kg, i.v.), a specific competitive antagonist of the vanilloid (capsaicin) receptor, strongly inhibited both phases of adrenaline secretion by capsaicin (50 microg/kg). Next, the effects of two capsaicin analogs on the adrenal catecholamine secretion were examined. Resiniferatoxin (20-200 ng/kg, i.v.), a naturally occurring phorbolester-like compound, provoked slow onset adrenaline secretion in a dose-dependent manner. Olvanil (2.46-246 microg/kg, i.v.), a synthesized non pungent capsaicin analog, also stimulated delayed catecholamine secretion dose-dependently. Capsazepine (20 mg/kg, i.v.) pretreatment prevented the resiniferatoxin (50 ng/kg)- and olvanil (24.6 microg/kg)-induced catecholamine secretion. These results suggest that some vanilloids (capsaicin, resiniferatoxin, olvanil) excite adrenaline secretion and such excitation is via the vanilloid receptor.     

Effects of proglumide on pancreatic endocrine and exocrine function in healthy humans

A comparative study was done on the pancreatic endocrine (insulin (IRI), human pancreatic polypeptide (hPP] and exocrine secretion (fluid volume, amylase output, bicarbonate output), before and after administration of proglumide. At the time of the test meal loading, plasma hPP and cholecystokinin (CCK) were also measured. During continuous i.v. administration of proglumide 750 mg and 1650 mg/h 30 min before CCK-8 (20 ng/kg) stimulation, no significant difference in the rise of plasma hPP level was observed, as compared with a single stimulus of CCK-8, nor were there any significant differences in the exocrine secretion. The values of hPP and CCK-8 under a load of test meal significantly elevated after a food load. Although hPP showed a significant inhibition with the administration of proglumide 1650 mg/h, plasma CCK-8 and blood sugar levels were not significantly different from control groups. Therefore, while proglumide has a very weak effect on the action of pancreatic endocrine function, it does have an inhibitory effect on pancreatic function, during physiological stimulation.