丁公藤碱降眼压作用机制的研究

目的探讨丁公藤碱降眼压作用的分子药理学机制。方法在恒定光源下用瞳孔尺测量兔瞳孔直径,用气动眼压计测量兔眼压,测量离体兔虹膜的收缩力,采用放射免疫法测定房水的环核苷酸含量。结果测定丁公藤碱缩瞳作用的ｐＤ２值为３．６０±０．１５,降眼压作用的ｐＤ２值为３．４９±０．０７,离体虹膜收缩作用的ｐＤ２值为６．３８±０．１２。Ｍ１～Ｍ３受体拮抗剂均可拮抗丁公藤碱的缩瞳作用、降眼压作用及离体虹膜收缩作用,其中以Ｍ３受体拮抗剂的拮抗作用最强。０．０１％丁公藤碱可使房水环磷酸腺苷（ｃｙｃｌｉｃａｄｅｎｏｓｉｎｅｍｏｎｏｐｈｏｓｐｈａｔｅ,ｃＡＭＰ）含量降低,环磷酸鸟苷（ｃｙｃｌｉｃｇｕａｎｏｓｉｎｅ３,５ｍｏｎｏｐｈｏｓｐｈａｔｅ;ｃＧＭＰ）含量升高。结论丁公藤碱的缩瞳和降眼压作用主要通过Ｍ３受体介导,其信号转导机制与环核苷酸系统相偶联。     

糖尿病大鼠视网膜组织中cAMP和cGMP含量变化及意义

目的探索糖尿病病程中视网膜组织的代谢机能。方法观察糖尿病大鼠发病后４、６、１２和１６周视网膜组织中环－磷酸腺苷（ｃｙｃｌｉｃａｄｅｎｏｓｉｎｅｍｏｎｏｐｈｏｓｐｈａｔｅ，ｃＡＭＰ）和环－磷酸鸟苷（ｃｙｃｌｉｃｇｕａｎｉｎｅｍｏｎｏｐｈｏｓｐｈａｔｅ，ｃＧＭＰ）含量的变化。结果在各实验时点，糖尿病大鼠视网膜组织中ｃＡＭＰ含量和ｃＡＭＰ／ｃＧＭＰ比值明显低于对照组（Ｐ＜０．０１），且随病程延长这些改变更显著，而ｃＧＭＰ含量则无明显改变（Ｐ＞０．０５）。结论糖尿病大鼠视网膜组织的代谢机能发生障碍，这可能在糖尿病视网膜病变的发生发展中起一定作用。     

高眼压与正常眼压家兔血浆、虹膜睫状体及房水中cAMP、cGMP含量变化

用放射免疫法对高眼压模型与正常眼压家兔的血浆，虹膜睫状体及房水中ｃＡＭＰ与ｃＧＭＰ含量进行检测。结果表明：高眼压组ｃＡＭＰ含量高于对照组（Ｐ＜０．０１），ｃＧＭＰ含量低于对照组（Ｐ＜０．０１）。说明ｃＡＭＰ与ｃＧＭＰ两者在眼压调节机制中可能有一定作用     

高眼压与正常眼压家兔血浆,虹膜睫状体及房水中cAMP,cGMP？…

用放射免疫法对高眼压模型与正常眼压家兔的血浆，虹膜睫状体及房水中ｃＡＭＰ与ｃＧＭＰ含量进行检测。结果表明：高眼压组ｃＡＭＰ含量高于对照组，ｃＧＭＰ含量低于对照组。说明ｃＡＭＰ与ｃＧＭＰ两者在眼压调节机制中可能有一定作用。     

鱼油对健康家兔眼压的影响及其机理初探

将２０只家兔随机等份分成Ａ组（喂清鱼油）和Ｂ组（喂浓鱼油），对用药前后的眼压、眼压描记及房水ｃＡＭＰ和ｃＧＭＰ值进行同组对比和两组间的比较。结果：（１）Ａ、Ｂ两组用药１４天后眼压分别下降０．７６±０．１７和０．９２±０．２０ｋＰａ。（２）Ａ、Ｂ两组用药１３天后Ｃ值分别升高０．０９±０．０２和０．０８±０．０４，Ｂ组Ｆ值下降１．０４±０．０９。（３）Ａ、Ｂ两组用药１４天后房水ｃＡＭＰ和ｃＧＭＰ分别升高１．３６±２．２１、１．９５±３．３４和５．９２±３．９６、３．１２±２．４３ｐｍｏｌ／ｍｌ。因此认为鱼油通过影响兔房水生成和排出降眼压并与其房水ｃＡＭＰ和ｃＧＭＰ含量改变有关。     

正常和白内障晶体上皮环磷酸腺苷与钙－钙调蛋白的研究

目的探讨晶体上皮钙－钙调蛋白（ｃａｌｃｉｕｍ－ｃａｌｍｏｄｕｌｉｎ，Ｃａ－ＣａＭ）与环磷酸腺苷（ｃｙｃｌｉｃａｄｅｎｏｓｉｎｅｍｏｎｏｐｈｏｓｐｈａｔｅ，ｃＡＭＰ）信使系统的关系以及可能的致白内障作用。方法采用酶促和放射免疫法，测定正常人和白内障晶体上皮ｃＡＭＰ、Ｃａ和ＣａＭ的含量。结果发现老年性白内障晶体上皮ｃＡＭＰ含量下降、Ｃａ－ＣａＭ含量升高。结论Ｃａ的升高是白内障形成的重要原因，ＣａＭ则“放大”了Ｃａ的作用，而ｃＡＭＰ含量降低可能使Ｃａ含量进一步升高。     

紫外光A/核黄素角膜交联后兔角膜基质内基质金属蛋白酶-1含量的变化

目的　检测紫外光Ａ／核黄素角膜交联（ｕｌｔｒａｖｉｏｌｅｔＡ／ｒｉｂｏｆｌａｖｉｎｃｏｒｎｅａｌｃｒｏｓｓ-ｌｉｎｋ-ｉｎｇ,ＵＶＡＲＣＸＬ）后兔角膜基质内基质金属蛋白酶（ｍａｔｒｉｘｍｅｔａｌｌｏｐｒｏｔｅｉｎａｓｅ,ＭＭＰ）-１的短期含量变化。方法　１５只新西兰白兔,随机分为３组,每组５只,Ａ组为空白对照组,Ｂ组为角膜交联后３ｄ,Ｃ组为角膜交联后７ｄ。Ｂ、Ｃ两组行ＵＶＡＲＣＸＬ。各组取角膜后去除角膜上皮和内皮细胞,应用ＥＬＩＳＡ法检测角膜基质内ＭＭＰ-１的含量。结果　Ａ组角膜基质内ＭＭＰ-１／总蛋白含量为（０．１４０±０．０３６）×１０－６,Ｂ组为（０．２４２±０．０５９）×１０－６,Ｃ组为（０．３７２±０．０６１）×１０－６,３组之间差异有统计学意义（Ｆ＝２４．０５１,Ｐ＝０．０００）。ＵＶＡＲＣＸＬ后３ｄ,兔角膜基质内ＭＭＰ-１含量显著升高,与Ａ组相比差异有统计学意义（Ｐ＜０．０５）,术后７ｄ其含量进一步升高,与Ｂ组相比差异有统计学意义（Ｐ＜０．０１）。结论　ＵＶＡＲＣＸＬ后７ｄ内,兔角膜基质内ＭＭＰ-１含量持续增加,推测ＭＭＰ-１可能对ＵＶＡＲＣＸＬ后的角膜基质重塑起一定作用。     

内皮素(ET_1)对豚鼠视网膜组织cAMP、cGMP影响的初步观察

目的观察全身及视网膜局部血管中ＥＴ１的水平，与豚鼠视网膜微循环和代谢的平衡状态。方法应用放射免疫方法测定了２６例健康豚鼠静脉内注射ＥＴ１后１０，２０，４０和８０分钟以及７例正常对照豚鼠视网膜组织中ｃＡＭＰ和ｃＧＭＰ的含量。结果静脉注射ＥＴ１后１０分钟ｃＡＭＰ、ｃＧＭＰ和ｃＡＭＰ／ｃＧＭＰ值降低，２０分钟ｃＡＭＰ值下降为最低（Ｐ＜０．００１），４０分钟时ｃＧＭＰ值（Ｐ＜０．０５）和ｃＡＭＰ／ｃＧＭＰ比值（Ｐ＜０．０１）下降为最低点，ｃＡＭＰ值呈回升趋势（Ｐ＜０．０１），８０分钟时三者已增至对照组低限（Ｐ＞０．０５）。结论提示全身和视网膜局部血管中ＥＴ１的水平与豚鼠视网膜微循环及代谢的平衡状态有关，并参与视网膜组织细胞局部代谢的调控。     

不同放射剂量下大鼠视网膜组织形态与氧化应激因子的变化

目的　通过直线加速器照射大鼠眼部制作放射性视网膜病变大鼠模型,观察大鼠视网膜组织形态与氧化应激因子的变化。方法　选取４５只２个月龄ＳＤ大鼠,随机分为正常对照组、１０Ｇｙ组、３０Ｇｙ组,每组１５只。直线加速器照射眼部,单次剂量１０Ｇｙ。１０Ｇｙ组放射１次。３０Ｇｙ组每周放射１次,连续３周,合计剂量３０Ｇｙ。放射后正常饲养３个月,处死各组大鼠并取眼球。采用ＨＥ染色观察视网膜组织形态,黄嘌呤法测视网膜超氧化物歧化酶（ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ,ＳＯＤ）活性、丙二醛（ｍａｌｏｎａｌｄｅｈｙｄｅ,ＭＤＡ）含量以及ＥＬＩＳＡ法测定活性氧自由基（ｒｅａｃｔｉｖｅｏｘｙｇｅｎｓｐｅｃｉｅｓ,ＲＯＳ）含量。结果　造模后３个月,３０Ｇｙ组视网膜各层组织结构松散,神经节细胞层及内核层水肿,１０Ｇｙ组模型大鼠视网膜仅神经节细胞层轻微水肿。与正常对照组相比,１０Ｇｙ组ＳＯＤ活性、ＭＤＡ及ＲＯＳ含量分别为（８８．８０±１６．４４）Ｕ·ｍｇｐｒｏｔ－１（Ｐ＜０．０５）、（１１．０２±４．０２）ｎｍｏｌ·ｍｇｐｒｏｔ－１（Ｐ＜０．０１）、（１６．８９±６．０２）Ｕ·ｍＬ－１（Ｐ＜０．０５）,差异均有统计学意义;３０Ｇｙ组ＳＯＤ活性、ＭＤＡ及ＲＯＳ含量分别为（７８．５０±１８．０９）Ｕ·ｍｇｐｒｏｔ－１、（１５．２６±５．３４）ｎｍｏｌ·ｍｇｐｒｏｔ－１、（２８．６６±８．８２）Ｕ·ｍＬ－１,三者差异均有显著统计学意义（均为Ｐ＜０．０１）。与１０Ｇｙ组比较,３０Ｇｙ组ＭＤＡ含量和ＲＯＳ含量均升高（均为Ｐ＜０．０５）。结论　直线加速器放射造模时,３０Ｇｙ为最佳放射造模剂量,造模后大鼠视网膜ＳＯＤ活性降低,ＭＡＤ及ＲＯＳ含量均升高,可能是放射性视网膜病变的发病基础。     

三磷肌醇,环磷酸腺苷对视网膜色素上皮功能影响的研究进展

视网膜色素上皮（ｒｅｔｉｎａｌｐｉｇｍｅｎｔｅｐｉｔｈｅｌｉｕｍ，ＲＰＥ）胞膜上具有特异性受体，能辨认视细胞外节膜盘（ｒｏｄｏｕｔｅｒｓｅｇｍｅｎｔ，ＲＯＳ）上的特异性配体，受体与配体相互作用，ＲＰＥ细胞内三磷肌醇（ｉｎｏｓｉｔｏｌｔｒｉｐｈｏｓｐｈａｔｅ，ＩＰ３）的水平增高，可促使ＲＰＥ对ＲＯＳ的吞噬。另外，ＲＰＥ胞膜上的毒蕈碱受体与其激动剂作用后也可促使ＲＰＥ细胞内ＩＰ３的增高及对ＲＯＳ吞噬的增强。环磷酸腺苷（ｃｙｃｌｉｃａｄｅｎｙｌａｔｅｍｏｎｏｐｈｏｓｐｈａｔｅ，ｃＡＭＰ）则作用相反，ＲＰＥ细胞膜上存在β２肾上腺素能受体，其受体激动剂可刺激ＲＰＥ细胞内ｃＡＭＰ浓度的迅速升高，抑制ＲＰＥ的吞噬功能。ＩＰ３和ｃＡＭＰ之间是否有拮抗作用目前尚不清楚。ｃＡＭＰ还抑制ＲＰＥ细胞的趋化、迁移、和增殖，其机制不明。另外，ｃＡＭＰ通过促进ＲＰＥ胞膜上ＮＡ＋－Ｋ＋－ＡＴＰ酶的活性及抑制ＣＬ－由视网膜向脉络膜的转运而抑制视网膜下液的转运。     

一氧化氮与青光眼患者眼压升高关系的研究

目的探讨一氧化氮(nitricoxide,NO)在青光眼患者眼压升高中的作用.方法对急性闭角型青光眼患者16例,老年性白内障患者29例,正常志愿者30例,应用高效液相色谱分析仪检测其血浆和房水中NO的含量,并以NO2和NO3之和表示.结果正常对照组血浆中NO的平均含量为(2969.37±862.85)ng/L;青光眼组血浆中NO的平均含量为(1390.78±302.95)ng/L,较对照组明显降低(t=2.853,P<0.01);白内障组血浆中NO的平均含量为(4234.89±1495.23)ng/L,较对照组明显升高.对照组房水中NO平均含量为(1405.83±602.70)ng/L;青光眼组房水中NO的平均含量为(2052.03±694.74)ng/L,与对照组比较差异无显著性(t=1.862,P＞0.05);白内障组房水中NO的平均含量为(2454.67±655.13)ng/L,较对照组明显升高.房水/血浆NO含量比值对照组为47.3%,白内障组为58.0%,二者的比值差异无显著性;而青光眼组为144.0%.结论血浆、房水中NO含量与急性闭角型青光眼眼压升高有关.     

Aqueous humor messengers in the transient decrease of intraocular pressure after ganglionectomy.

Intraocular pressure (IOP) decreases in rabbits 1 day after superior cervical ganglionectomy. It was hypothesized that this IOP decrease was caused by an accumulation of norepinephrine (NE) released from the iris-ciliary body into the aqueous humor during nerve degeneration. Direct measurement of aqueous humor NE concentration, however, was not successful because of the technical difficulty. In the current study, aqueous humor NE after superior cervical ganglionectomy was extracted and quantified using high-performance liquid chromatography-electrochemical detection. Twelve New Zealand albino rabbits were maintained in a daily 12-hr light-12-hr dark environment. Unilateral ganglionectomy was done on these rabbits during the light phase under halothane anesthesia. Twenty-two hours after the procedure, a significant IOP decrease occurred. The IOP was 16.1 +/- 0.6 mmHg (mean +/- the standard error of the mean) in the operated eye and 20.9 +/- 0.6 mmHg in the contralateral eye (P < 0.01). Aqueous humor NE concentration in the operated eye (475 +/- 81 pg/ml) was not different from that in the contralateral eye (469 +/- 58 pg/ml). However, the concentration of aqueous humor cyclic adenosine monophosphate (cAMP) in the operated eye (29.8 +/- 6.8 pmol/ml) was significantly higher (P < 0.05) than that in the contralateral eye (11.7 +/- 0.8 pmol/ml). These data indicate that aqueous humor NE per se does not cause the transient IOP decrease after superior cervical ganglionectomy and cAMP-mediated ocular activities may be involved in this change in IOP.     

直肌睫状前血管的分离和保留对兔眼前段缺血综合征的预防作用

目的　观察兔眼眼外直肌手术中直肌睫状前血管 (ACVs)的分离和保留对预防眼前段缺血综合征 (ASI)的作用。方法　将 32只健康新西兰白兔随机分为 4组 ,每组右眼分离和保留ACVs,左眼去除ACVs。A组 :切断 2条水平直肌 ;B组 :切断 2条垂直直肌 ;C组 :切断内、外直肌和 1条垂直直肌 ;D组 :切断 4条直肌。术前和术后裂隙灯显微镜下观察眼前段的体征 ,测量眼压、房水中总蛋白和乳酸的浓度。术后 4周处死动物 ,光镜和电镜下检查虹膜和睫状体的超微结构。结果 4组中右眼术后均未发生缺血性改变。A组左眼无明显缺血改变 ,B组左眼仅出现轻度缺血的病理学改变。C、D组左眼出现明显甚至严重的ASI体征 ,眼压出现下降趋势 ,C组眼压术前为 (17 2 1± 3 76 )mmHg(1mmHg =0 133kPa) ,术后最低降至 (14 4 8± 3 36 )mmHg(P <0 0 5 ) ,D组眼压术前为 (16 6 8± 2 33)mmHg,术后最低降至 (3 17± 0 92 )mmHg(P <0 0 5 ) ;房水中总蛋白和乳酸的浓度明显增高 ,C组术前分别为(5 0 5 3± 5 0 )mg/L和 (7 5 4± 0 4 7)g/L ,术后分别最高升至 (811 9± 4 4 4 )mg/L和 (11 0 0± 3 5 9)g/L(P<0 0 5 ) ;D组术前分别为 (5 0 4 6± 4 1)mg/L和 (7 17± 1 4 4 )g/L ,术后分别最高升至 (10 2 5 8± 78 3)mg/L和 (8 2 3± 1     

Morphine-stimulated nitric oxide release in rabbit aqueous humor

Recent studies in our laboratory have demonstrated a role of nitric oxide (NO) in morphine-induced reduction of intraocular pressure (IOP) and pupil diameter (PD) in the New Zealand white (NZW) rabbit. The present study was designed to determine the effect of morphine on NO release in the aqueous humor of NZW rabbits, as this effect could be associated with morphine-mediated changes in aqueous humor dynamics and iris function. Dark-adapted NZW rabbits were treated as follows: (1) treatment with morphine (10, 33 or 100 microg, 5 min); (2) treatment with morphine or endomorphin-1 for 5, 15 or 30 min; (3) pretreatment with naloxone (100 microg), L-NAME (125 microg) or reduced glutathione (GSH, 100 microg) for 30 min, followed by treatment with morphine (100 microg, 5 min). After the various treatment regimens, aqueous humor samples were obtained by paracenthesis and immediately assayed for nitrates and nitrites (an index of NO production), using a microplate assay kit. Morphine caused a dose-dependent increase in the levels of NO in aqueous humor after 5 min of treatment with each dose. Rabbits treated with endomorphin-1 (100 microg) had no significant change in NO levels in aqueous at any point in the course of time. Aqueous samples from rabbits treated with morphine (100 microg) for 5 min increased from 29.84+/-2.39 microM (control) to 183.94+/-23.48 microM (treated). The increase in NO levels by morphine (100 microg, 5 min) was completely inhibited in the presence of naloxone (100 microg), L-NAME (125 microg) or GSH (100 microg). These results indicate that morphine-induced increase in NO production in aqueous humor is a transient response that is linked to the activation of mu opioid receptors. Data obtained suggest that morphine-stimulated changes in ocular hydrodynamics and iris function are due, in part, to increased release of NO in aqueous humor. In addition, the sensitivity of the response to l-NAME and GSH suggests that morphine-induced release of nitric oxide into aqueous humor is mediated by activation of mu-3 opioid receptors found in the anterior segment of the eye.     

新生血管性青光眼血管内皮生长因子和血小板衍生生长因子含量及其相关影响因素

目的 观察新生血管性青光眼（NVG）患者眼内血管内皮生长因子（VEGF）和血小板衍生生长因子（PDGF）含量,并分析其相关影响因素.方法 实验研究.NVG患者54 例（54眼）,其中视网膜中央静脉阻塞（CRVO）17眼,糖尿病性视网膜病变（DR）22眼,视网膜血管炎（Eales病）4眼,视网膜脱离（RD）术后4眼,未知原因7眼.虹膜新生血管Ⅰ级17眼,Ⅱ级12眼,Ⅲ级13眼,Ⅳ级12眼.36眼曾行视网膜光凝和（或）冷凝治疗.10只新鲜健康角膜供体眼作为正常对照组.抽取两组的房水和玻璃体液样本,采用酶联免疫吸附试验（ELISA）检测其中VEGF和PDGF含量.对NVG组和正常对照组VEGF和PDGF含量的比较采用Mann-Whitney U检验,不同原发病、不同等级虹膜新生血管、视网膜光凝和（或）冷凝治疗组与未治疗组之间VEGF和PDGF含量的比较分别采用方差分析、LsD-t检验和独立样本t检验,并对各组VEGF和PDGF含量进行Pearson相关分析.结果 NVG组房水中VEGF和PDGF含量分别为（926.3±223.5）ng/L和（226.2±81.5）ng/L,玻璃体液中分别为（1096.1±235.9）ng/L和（375.3±141.5）ng/L,均高于正常对照组（Z 房水VECG=-4.993,Z房水PDGF=-4.891,Z玻璃体VEGF=-4.991,Z玻璃体PDGF＝-4.992,P均=0.000）.不同原发病组比较：CRVO组房水和玻璃体液中VEGF含量均高于不明原凶组（t房水=1.746,P房水＝0.033;t玻璃体=1.917,P玻璃体=0.027）,其他各组之间VEGF含量差异均无统计学意义;DR组房水和玻璃体液中PDGF含量高于Eales病组（t房水=1.697,P房水：0.043;t玻璃体=1.762,P玻璃体=0.038）,其他各组间PDGF含量差异均无统计学意义.不同虹膜新牛血管分级组比较：各组房水和玻璃体液中VEGF含量差异均无统计学意义：虹膜新生血管Ⅳ级组玻璃体液中PDGF含量高于Ⅲ级组（t=1.740,P=0.049）.视网膜光凝和（或）冷凝治疗后,房水及玻璃体液中VEGF和PDGF的含量均低于未治疗组（Z房水VEGF＝2.945,P房水VEGF=0.003;t房水PDGF＝3.199,P房水PDGF＝0.002;Z玻璃体VEGF=3.165,P玻璃体VEGF＝002;t玻璃体PDGF＝2.984,P玻璃体PDGF＝0.004）.相关分析显示：NVG组房水中VEGF和PDGF含量呈正相关（r=0.305,P=0.025）,玻璃体液中VEGF和PDGF含量也呈正相关（r=0.303,P＝0.026）;CRVO组玻璃体液中VEGF和PDGF含量呈正相关（r=0.503,P＝0.040）;DR组房水中VEGF和PDGF含量呈正相关（r=0.462,P=0.030）.结论 NVG中VEGF和PDGF含量的变化与其原发病、虹膜新生血管严重程度有关,视网膜光凝和（或）冷凝治疗可抑制VEGF和PDGF的产生.     

Aqueous humor and serum concentration of hydroxyproline in pseudoexfoliation syndrome

PURPOSE: To determine the concentration of hydroxyproline (Hyp) in aqueous humor and serum samples of patients with and without pseudoexfoliation (PEX). PATIENTS AND METHODS: Aqueous humor and serum Hyp levels were measured in cataract patients. Patients were divided into PEX and control groups. Samples were obtained from 27 cataract patients with PEX and 25 cataract patients without PEX. Patients had no elevated intraocular pressure or glaucoma. Hyp concentration was determined spectrophotometrically. RESULTS: Mean Hyp concentration in the PEX aqueous (0.86+/-0.27 mg/L) and serum (40.8+/-6.14 mg/L) samples was significantly higher than that measured in the control aqueous (0.56+/-0.2 mg/L) and serum (34.51+/-6.82 mg/L) samples, respectively (P<0.001, P=0.001). No significant correlation could be found between aqueous humor and serum Hyp concentrations. CONCLUSIONS: The higher levels of Hyp could be a sign of increased collagen turnover in PEX syndrome.     

Studies on the circadian rhythm of IOP in rabbits: correlation with aqueous inflow and cAMP content

We investigated the relationship of aqueous humor inflow rate and cyclic AMP concentrations to the spontaneous and dramatic changes in IOP associated with onset of darkness in our previously described model of circadian rhythm of intraocular pressure. After onset of darkness, rabbits entrained in an environment with a daily alternating cycle of 12 hours light and 12 hours darkness (12L:12D) showed an 85% increase in outflow pressure, a nearly 60% increase in aqueous inflow rate and an 80% increase in aqueous cAMP. Animals desynchronized by an unpredictable light cycle showed no increase in IOP or inflow rate when measured at the same time intervals as were the entrained animals. Thus, the IOP, aqueous inflow rate and aqueous cAMP are all seen to change in the same direction in a pharmacologically unperturbed rabbit eye. Previous pharmacological studies in rabbits have correlated an increase in cAMP with a decrease in IOP and aqueous inflow.     

口服中药熊胆粉在兔眼内通透性的研究

目的探讨口服中药熊胆粉透过血-眼屏障到达相应靶组织的机制及其作用。方法56只家兔按照随机数字表法分成对照组8只和给药组48只。给药组再随机分成6个亚组,每个亚组8只,空腹12h给予兔中药熊胆粉100mg/kg体重灌胃,分别在灌胃后0.5、1.0、2.0、4.0、6.0、8.0h于家兔耳缘静脉采血2ml,均左眼取房水、右眼取玻璃体。对照组的实验方法同给药组,处理时间记为0h。利用高效液相色谱仪法(HPLC)测定熊胆粉中标记物牛磺熊脱氧胆酸(TUDCA)在血液、房水、玻璃体内的浓度。结果利用HPLC可准确测血液、房水、玻璃体内TUDCA浓度,其中血液中浓度为(999.1±17.2)~(1300.6±78.2)μg/ml;房水中浓度为(12.7±1.4)~(47.8±4.7)μg/ml;玻璃体中浓度为(10.8±2.9)~(57.9±7.9)μg/ml。给药组各时间点血液、房水、玻璃体中TUDCA的浓度分别与对照组相比,差异有统计学意义(P<0.01);不同时间点房水和玻璃体内TUDCA浓度之间的比较,差异无统计学意义(P>0.05)。结论口服中药熊胆粉能透过血-眼屏障到达相应靶组织,于房水和玻璃体中的浓度明显小于血液中浓度,进入房水和玻璃体的能力相近。(中华眼科杂志,2006,421023-1025)     

Biphasic intraocular pressure response to Q-switched Nd:YAG laser irradiation of the iris and the apparent mediatory role of prostaglandins

In rabbits, laser irradiation of the iris causes an immediate rise in intraocular pressure (IOP), with a concomitant increase of prostaglandins (PGs) in the aqueous humor. We studied IOP responses to Q-switched Nd:YAG laser application to the iris in unanesthetized rabbits, and found that a prolonged IOP reduction lasting for 6-24 hr invariably followed the transient IOP rise of 0.5-2 hr duration. The magnitude of both the IOP rise and reduction was dependent on the level of laser energy. A masked, randomized study revealed that the intraperitoneal administration of indomethacin (50 mg kg-1) prior to laser application significantly reduced the ocular hypertensive and hypotensive responses to laser irradiation (energy: 24 mJ). The maximum IOP rise from baseline was 5.4 +/- 3.0 mmHg (n = 10) with the intraperitoneal vehicle and 1.5 +/- 4.2 mmHg (n = 10) with intraperitoneal indomethacin administration. Thus, the difference was statistically significant (P less than 0.025, Student's t-test). The maximum IOP reduction from baseline was -8.5 +/- 2.6 mmHg (n = 10) with the intraperitoneal vehicle and -4.0 +/- 2.4 mmHg (n = 10) with intraperitoneal indomethacin (P less than 0.001, Student's t-test). The concentration of PGE2 in the aqueous humor, as determined by radioimmunoassay on samples obtained at 2 and 4 hr after laser application, was found to be significantly increased in rabbits that received the vehicle solution but not in animals that were pretreated with intraperitoneal injection of indomethacin. This suggests that this PG or other cyclooxygenase products are involved with mediation of the initial IOP increase and the prolonged decrease in IOP that follows laser irradiation of the iris.