TRPV1对LPS致热大鼠体温及下丘脑中Ca2＋浓度和cAMP含量的影响

目的探讨TRPV1在脂多糖（LPS）致大鼠发热过程中的作用和机制。方法48只6SD大鼠随机分为4组,正常对照组（N）、capsazepine组（CPZ）、LPS组（LPS）和capsaz—epine＋LPS组（CPZ＋LPS）。连续观察体温变化;在发热高峰期通过颈椎脱臼迅速处死动物,以Fura-2／AM为荧光指示剂,测定下丘脑细胞内[Ca2＋]i;应用放射免疫法检测下丘脑中cAMP含量的变化。结果①各组体温变化最大值（△Tmax）由高至低顺序为：CPZ＋LPS组〉LPS组〉CPZ组〉N组;其中,CPZ＋LPS组与LPS组比较,AT（300～480min期间）及体温反应指数TRI。均增高（P〈0．01）;②在发热高峰期,CPZ＋LPS组[Ca2＋]i明显低于其它3组（P〈0．01）;③CPZ＋LPS组cAMP含量与其它组比较增多（P〈0．01）。结论capsazepine可能通过阻断下丘脑TRPV1通道,改变细胞内钙离子浓度,进而影响LPS性发热过程。     

在LPS致大鼠发热过程中下丘脑TRPV4对体温及cAMP含量、[Ca~(2+)]i浓度的影响

目的探讨TRPV4在发热时是否参与体温调节过程。方法用脂多糖复制大鼠发热模型,结合应用钌红抑制TR-PV4的活性,观察发热时的下丘脑组织中TRPV4含量、钙离子浓度变化与cAMP含量的关系。结果单独给予钌红组体温降低;钌红+LPS组与LPS组相比,△T、cAMP与[Ca2+]i增高幅度均降低;钌红组与钌红+LPS组TRPV4表达明显低于对照组。结论①TRPV4通道可能参与正常体温的维持;②通过激活TRPV4通道,使钙离子内流增多,进而中枢发热介质cAMP表达增多,这可能是LPS致大鼠发热的重要途径。     

低温时蛙皮素对IL-1β致热大鼠下丘脑和血浆cAMP含量的影响

目的以大鼠为实验对象建立发热动物模型,研究4℃时蛙皮素的降温作用及其与cAMP的关系。方法选择SD雄性大鼠,4℃下侧脑室微量注射蛙皮素、白细胞介素-1β,观察大鼠体温变化情况,并测定下丘脑和血浆中cAMP含量。结果在IL-1β诱导发热大鼠中,下丘脑及血浆中cAMP含量与对照组相比升高(P<0.01);蛙皮素可以降低大鼠正常体温,下丘脑cAMP含量与对照组相比亦随之降低(P<0.01);预先侧脑室注射蛙皮素能翻转大鼠IL-1β性发热,且下丘脑cAMP含量与IL-1β组相比明显下降(P<0.01)。结论4℃时蛙皮素能抑制IL-1β发热,其机制有可能是通过抑制cAMP合成或释放实现的。     

脑室给予不同剂量的Capsazepine对LPS致大鼠发热过程的影响

目的在大鼠侧脑室内给予不同剂量的瞬时受体电位香草酸受体1(transient receptor potential vanilloid 1,TRPV1)拮抗剂Capsazepine,观察对LPS致热过程的影响。方法在侧脑室内预先给与3种剂量Capsazepine,随之腹腔给与LPS致热。在腹腔内埋植发射子遥测体温变化过程,同时应用荧光测定法检测下丘脑细胞内钙离子浓度的变化,Western blot方法检测TRPV1表达水平。结果随着Capsazepine剂量增大,LPS致大鼠发热水平升高,下丘脑细胞内钙离子浓度减少,TRPV1表达水平降低。结论 Capsazepine作用于大鼠下丘脑,可使LPS诱导的发热水平提高,此效应可能与TRPV1的作用有关。     

CCK-8抗炎作用中DAG-PKC信号通路对cAMP-PKA信号通路的影响

目的探讨CCK-8抗炎作用中DAG-PKC信号通路对cAMP-PKA信号通路的影响。方法分离纯化大鼠PIMs,分别用LPS、CCK、LPS+CCK、PMA、SC-3088、LPS+PMA、LPS+SC-3088、CCK+PMA、CCK+SC-3088、LPS+CCK+PMA、LPS+CCK+SC-3088孵育一定时间,采用125I-cAMP放射免疫分析法测定细胞内cAMP含量,用放射激酶法测定PKA活性。结果单独应用PMA和SC-3088孵育大鼠PIMs,细胞内cAMP含量和PKA活性与正常对照组相比无明显变化(P>0.05)。PMA可升高LPS作用下的细胞内cAMP含量和PKA活性(P<0.01),SC-3088则可使LPS作用下的细胞内cAMP含量和PKA活性降低(P<0.01)。分别应用PMA、SC-3088与CCK共同孵育,则CCK+PMA组细胞内cAMP含量和PKA活性高于单独应用CCK组(P<0.01),CCK+SC-3088组则降低(P<0.01)。与LPS+CCK组相比,PMA+LPS+CCK组细胞内cAMP含量和PKA活性升高(P<0.01),而SC-3088+LPS+CCK组细胞内cAMP含量和PKA活性降低(P<0.01)。结论在LPS诱导的大鼠PIMs,CCK-8可通过激活cAMP-PKA信号通路发挥抗炎作用;DAG-PKC信号通路的活化对cAMP-PKA信号通路有正性调节作用。     

穿琥宁对致热大鼠下丘脑组织中PGE2和cAMP含量的影响

目的探讨穿琥宁注射液的解热机制.方法用酵母混悬液复制大鼠发热模型,观察穿琥宁注射液对大鼠体温的影响及其量效关系,并采用放免法测定下丘脑中PGE2和cAMP含量.结果发热模型组在皮下注射酵母混悬液6 h时,△T及TRI6明显高于对照组(P＜0.01),穿琥宁125、250 mg·kg-1组的△T及穿琥宁250 mg·kg-1组的TRI6明显低于发热模型组(P＜0.01),且穿琥宁250 mg·kg-1组的△T及TRI6低于125 mg·kg-1组(P＜0.01).发热模型组下丘脑中PGE2和cAMP的含量明显高于对照组(P＜0.01),而穿琥宁125、250 mg·kg-1组明显低于发热模型组(P＜0.01),且穿琥宁250 mg·kg-1组低于125 mg·kg-1组(P＜0.05).△T与下丘脑中PGE2和cAMP的含量之间呈明显正相关(P＜0.01).结论穿琥宁注射液可通过抑制下丘脑中PGE2和cAMP含量的升高而发挥解热作用,并存在量效关系.     

纳洛酮对IL-1β致热大鼠体温及下丘脑中cAMP和HSP70含量的影响

目的研究阿片受体在IL-1β致热大鼠发热过程中的作用及机制。方法经大鼠侧脑室微量注射纳洛酮和(或)IL-1β,观察大鼠体温变化情况,并测定下丘脑中cAMP含量和HSP70表达。结果纳洛酮能够减弱IL-1β致热效应,同时下丘脑中cAMP含量和HSP70表达水平也相应减少(P<0.01)。结论阿片受体拮抗剂纳洛酮能够抑制大鼠IL-1β性发热,其机制可能与降低下丘脑中cAMP的合成有关;同时可见HSP70表达水平降低。     

BN对IL-1β致热的抑制作用及POA和血中cAMP的影响

目的　研究蛙皮素的降大鼠体温作用及与cAMP的关系。方法　选择SD雄性大鼠 ,侧脑室微量注射蛙皮素、白细胞介素 1β ,观察大鼠体温变化情况 ,并测定下丘脑和血浆中cAMP含量。结果　①在侧脑室注射IL 1β诱导发热大鼠中 ,下丘脑及血浆中cAMP含量显著升高 (P <0 0 1,P<0 0 1) ;②BN能降低大鼠正常体温 ,cAMP含量亦随之显著降低 (P <0 0 1,P <0 0 5 ) ;③预先侧脑室注射BN能明显抑制大鼠IL 1β性发热 ,且cAMP含量亦明显下降 (P <0 0 1,P <0 0 5 )。结论　提示蛙皮素能抑制IL 1β发热 ,其机制有可能是通过抑制cAMP合成实现     

体外培育牛黄对急性肺损伤大鼠缺氧诱导因子-1α表达的影响及抗氧化作用的研究

目的探讨体外培育牛黄对抗脂多糖(LPS)所致大鼠急性肺损伤的保护作用及可能机制。方法雄性Wistar大鼠18只,随机数字表法随机分为对照组、LPS组、体外培育牛黄干预组(牛黄+LPS)。免疫组织化学法检测缺氧诱导因子1α(HIF-1α)的表达,并检测肺组织匀浆中超氧化物歧化酶(SOD)、丙二醛(MDA)及髓过氧化物酶(MPO)含量变化。结果 1LPS组HIF-1α水平较对照组增高,差异有统计学意义(P<0.01),牛黄+LPS组HIF-1α水平较LPS组降低,差异有统计学意义(P<0.01);2LPS组MDA及MPO水平较对照组增高,差异有统计学意义(均P<0.01),SOD较对照组降低,差异有统计学意义(P<0.01);3牛黄+LPS组MDA及MPO水平较LPS组降低,差异有统计学意义(均P<0.01),SOD较LPS组增高,差异有统计学意义(P<0.05)。结论体外培育牛黄通过减少HIF-1α表达及抗氧化作用对LPS引起的急性肺损伤起到保护作用。     

孕酮对幼年大鼠感染性脑水肿水通道蛋白4表达的影响

目的 观察内毒素(LPS)致幼年大鼠感染性脑水肿后,腹腔注射孕酮(Prog)对水通道蛋白4(AQP4)表达的影响.方法 将90只幼年大鼠随机分为对照组(C,n=10),内毒素组(LPS,n=40)和内毒素+孕酮组(LPS+Prog,n=40).建立LPS致大鼠感染性脑水肿模型后1 h,LPS+Prog组和LPS组分别腹腔注射孕酮和生理盐水,以后每6小时注射一次.手术后6、12、24和48 h处死动物,分别行脑组织含水量的测定,用免疫组化和RT-PCR检测脑组织内AQP4表达水平.结果 LPS组脑组织含水量明显高于C组和LPS+Prog组(P<0.01).在LPS注射6 h时,幼鼠脑组织 AQP4表达明显增加,12 h达高峰.LPS+Prog组在LPS注射后12 h时,脑组织中AQP4在蛋白水平和mRNA水平的表达均低于LPS组(P<0.01).结论 孕酮可能在转录和翻译水平下调AQP4的表达,从而抑制LPS诱导的幼年大鼠感染性脑水肿的发生发展.     

Interaction of estrone and estradiol with DNA and protein of liver and kidney in rat and hamster in vivo and in vitro

[6,7-³H] Estrone (E) and [6,7-³H]estradiol-17 (E₂) have been synthesized by reduction of 6-dehydroestrone and 6-dehydroestradiol with tritium gas. Tritiated E and E₂ were administered by oral gavage to female rats and to male and female hamsters on a dose level of about 300 g/kg (54 mCi/kg). After 8 h, the liver was excised from the rats; liver and kidneys were taken from the hamsters. DNA was purified either directly from an organ homogenate or via chromatin. The radioactivity in the DNA was expressed in the units of the Covalent Binding Index, CBI = (mol chemical bound per mol DNA-P)/(mmol chemical administered per kg b.w.). Rat liver DNA isolated via chromatin exhibited the very low values of 0.08 and 0.09 for E and E₂, respectively. The respective figures in hamster liver were 0.08 and 0.11 in females and 0.21 and 0.18 in the males. DNA isolated from the kidney revealed a detectable radioactivity only in the female, with values of 0.03 and 0.05 for E and E₂, respectively. The values for male hamster kidney were < 0.01 for both hormones. The minute radioactivity detectable in the DNA samples does not represent covalent binding to DNA, however, as indicated by two sets of control experiments. (A) Analysis by HPLC of the nucleosides prepared by enzyme digest of liver DNA isolated directly or via chromatin did not reveal any consistent peak which could have been attributed to a nucleoside-steroid adduct. (B) All DNA radioactivity could be due to protein contaminations, because the specific activity of chromatin protein was determined to be more than 3,000 times higher than of DNA. The high affinity of the hormone to protein was also demonstrated by in vitro incubations, where it could be shown that the specific activity of DNA and protein was essentially proportional to the concentration of radiolabelled hormone in the organ homogenate, regardless of whether the animal was treated or whether the hormone was added in vitro to the homogenate.Carcinogens acting by covalent DNA binding can be classified according to potency on the basis of the Covalent Binding Index. Values of 10³–10⁴ have been found for potent, 10² for moderate, and 1–10 for weak carcinogens. Since estrone is moderately carcinogenic for the kidney of the male hamster, a CBI of about 100 would be expected. The actually measured limit of detection of 0.01 places covalent DNA binding among the highly unlikely mechanisms of action. Similar considerations can be made for the liver where any true covalent DNA binding must be below a level of 0.01. It is concluded that an observable tumor induction by estrone or estradiol is unlikely to be due to DNA binding.Paper presented at the Satellite Symposium of the European Society of Toxicology, Rome, March 29, 1983     

Mechanisms of antiplatelet and antithrombotic activity of midazolam in in vitro and in vivo studies

Dopamine regulates various physiological functions in the central nervous system and the periphery. Dysfunction of the dopamine system is implicated in a wide variety of disorders and behaviors including schizophrenia, addiction, and attention-deficit hyperactivity disorder. Medications that modulate dopamine signaling have therapeutic efficacy on the treatment of these disorders. However, the causes of these disorders and the role of dopamine are still unclear. Studying the dopamine system in a model organism, such as Caenorhabditis elegans, allows the genetic analysis in a simple and well-described nervous system, which may provide new insight into the molecular mechanisms of dopamine signaling. In this review, we summarize recent findings on pharmacological and biochemical properties of the C. elegans dopamine receptors and their physiological role in the control of behavior.     

Penetration and action of edoxudine in vitro and in vivo

The penetration of 5-ethyl-2'-deoxyuridine (edoxudine, Aedurid) from gel base with and without the addition of urea and other adjuvant has been studied in an in vitro model using guinea pig skin. The formulation of 3% edoxudine gel with 5% urea showed the best results. In vivo experiments on hairless mice infected intracutaneously with herpes simplex virus type 1 also showed this formulation's good efficacy as compared to other formulations.     

Extraction and determination of prednisolone in drugs and excipients in ointments and creams and the uniformity of distribution in prednisolone ointment

For the purpose of measuring the contents of prednisolone in low concentrated ointments and creams an instruction was elaborated that includes several steps of extraction, in the resulting solution of which the assay of the steroid by Blue Tetrazolium reaction will be done. The procedure permits the determination of prednisolone in presence of most of usual ingredients of ointment bases except wool alcohols. Also no influence is given by some remedies combined with prednisolone for topical application except coal tar solution. The results confirm a correct reflection of the steroid contents declared respectively the recovery of the steroid added to various ointment bases. Introducing discussion to content uniformity concerning low concentrated ointments is made, and some deviations are shown.     

Strain-dependency in motor activity and in concentration and turnover of catecholamines in synchronized rats

Circadian rhythm in motor activity was studied with an Animex motimeter in six strains of rats (ACI, BH, BS, DA, LEW, TNO) synchronized by a 12 hr light: 12 hr dark cycle. ANOVA revealed significant interstrain differences in motor activity as well as in the concentration and turnover of central noradrenaline and dopamine. Strain-dependent differences were also found with regard to tyrosine hydroxylase inhibition on motor activity. However, no significant interstrain correlations were found between endogenous concentration and/or turnover rates of the catecholamines and motor activity in normal and drug-treated rats.     

Simultaneous Determination of Sulfation and Glucuronidation of Flavones in FVB Mouse Intestine in Vitro and in Vivo

Glucuronidation and sulfation are the two major phase II metabolic pathways for flavones, natural compounds that hold great potential for improving human health. We investigated the positional preference for sulfation and glucuronidation of seven structurally similar flavones in vitro and in situ. An FVB mouse intestinal perfusion model was used in addition to three small intestine S9 fractions catalyzing sulfation only (Sult enzymes), glucuronidation only (Ugt enzymes) or both (Sult and Ugt enzymes). In both the single and co‐reaction S9 systems, flavones containing 7‐OH groups were conjugated only at 7‐OH despite the presence of other hydroxyl groups, and 7‐OH glucuronidation was faster than sulfation (P < 0.05). The sulfation rate was enhanced in the Sult‐Ugt co‐reaction system, while glucuronidation was usually unchanged by the presence of Sult. In the intestinal perfusate, sulfation patterns were the same in the small intestine and colon, and the excretion rate of 7‐O‐sulfate was the fastest or second fastest. The excretion of 7‐O‐glucuronidates was faster in small intestine (P < 0.05) than in colon. The S9‐mediated sulfation rates of the different flavones were significantly correlated with the excretion rates of the same flavones from perfused intestine. In conclusion, flavone glucuronidation and sulfation rates were sensitive to minor changes in molecular structure. In intestinal S9 fractions, both Ugts and Sults preferentially catalyzed reactions at 7‐OH. The sulfation rate was significantly enhanced by simultaneous glucuronidation, but glucuronidation was unaltered by sulfation. Sulfation rates in mouse S9 fractions correlated with sulfation rates in perfused intestine. Copyright © 2011 John Wiley & Sons, Ltd.     

Pharmacokinetics and tolerability of artesunate and amodiaquine alone and in combination in healthy volunteers

Objectives  The WHO recommends artemisinin-based combination therapies for treatment of uncomplicated falciparum malaria. At least 15 African countries have adopted artesunate plus amodiaquine as treatment policy. As no pharmacokinetic data on this combination have been published to date, we investigated its pharmacokinetic interactions and tolerability in healthy volunteers in Africa. Methods  In a randomized, three-phase, cross-over study, amodiaquine (10 mg/kg) and artesunate (4 mg/kg) were given as single oral doses to 15 healthy volunteers. Artesunate was given to all volunteers on day 0. On day 7 they received either amodiaquine or amodiaquine plus artesunate and the alternative regimen on day 28. The pharmacokinetics of artesunate and amodiaquine and their main active metabolites dihydroartemisinin and desethylamodiaquine were compared following monotherapy and combination therapy using analysis of variance. Results  Thirteen volunteers completed the study, and pharmacokinetic parameters could be determined for twelve volunteers. When given in combination, the mean AUC was lower for dihydroartemisinin [ratio 67% (95% CI 51–88%); P = 0.008] and desethylamodiaquine [ratio 65% (95% CI 46–90%); P = 0.015] when compared with monotherapy. Adverse events of concern occurred in four volunteers (27%): grade 3 transaminitis (n = 1), neutropaenia (n = 2), and hypersensitivity (n = 1). Conclusion  The total drug exposure to both drugs was reduced significantly when they were given in combination. The clinical significance of these interactions is unclear and must be studied in malaria patients. The frequency and nature of adverse events among the healthy volunteers were of concern, and suggest laboratory monitoring would be needed in malaria patients treated with artesunate plus amodiaquine.     

A review of in vitro and in vivo models of oesophageal and gastric cancer

Importance of the field: Oesophageal and gastric cancers are leading causes of cancer-related mortality. In the era of targeted therapy and individualized treatment strategies, novel treatments for upper-gastrointestinal cancers are only just emerging compared to significant advances in other solid tumour types such as colorectal, breast and lung cancers. Clinical trials are investigating the value of established targeted agents for the treatment of oesophageal and gastric malignancies; however none are used in routine clinical practice.

Areas covered in this review: In this review we have looked at current in vitro and in vivo models of oesophageal and gastric cancers which may improve our understanding of the biology of these tumours and lead to the development of new preventative, diagnostic and therapeutic approaches.

What the reader will gain: We discuss the limitations of our current models and the challenges associated with research into these cancers.

Take home message: The lack of appropriate models for drug development in oesophageal and gastric cancers has hindered the progress of targeted therapy in this field.     

葛根芩连煎剂中小檗碱在犬体内药动学研究

目的:测定葛根芩连煎剂与黄连单煎剂犬血中小檗碱的含量,分析配伍后(全方)对小檗碱体内过程的影响。方法:采用高效液相色谱法,测定不同时间点犬血浆中小檗碱的含量,WinNonlin软件计算药动学参数。结果:葛根芩连煎剂及黄连单煎剂中小檗碱在犬体内药-时曲线均符合一室模型,主要药动学参数AUC(0-∞)(1·25±0·06)、(14·71±0·54)(μg·h)/ml,tmax(1·92±0·31)、(3·03±0·07)h,Cmax(0·17±0·01)、(1·79±0·03)μg/ml。结论:葛根芩连煎剂配伍后与单方比较小檗碱入血浓度及生物利用度都降低。     

Comparative in vivo and in vitro studies of phenytoin protein binding and in vitro lipolysis in plasma of pregnant and nonpregnant rats

This investigation was designed to determine the cause of the changes in drug protein binding that occur in rat plasma, particularly in plasma from pregnant animals, during in vitro drug-protein binding measurements. In vivo estimates of phenytoin binding in plasma were obtained from steady-state CSF-plasma concentration ratios in pregnant and nonpregnant rats. Immediate ultrafiltration of heparin- or EDTA-anticoagulated plasma yielded phenytoin free fraction values that were in good agreement with in vivo estimates for nonpregnant rats but that were about one-third higher than in vivo estimates for pregnant animals. In vitro free fraction values tended to increase during incubation of plasma and/or during equilibrium dialysis. The concentrations of the four major endogenous free fatty acids were similar in plasma of pregnant and nonpregnant rats if determined immediately after blood collection. Six hours of incubation at 37 degrees C caused fatty acid concentrations to increase about fivefold and twofold in heparin-anticoagulated plasma from pregnant and nonpregnant animals, respectively. The corresponding increases in EDTA-anticoagulated plasma were only about twofold and 1.14-fold, respectively. These changes were associated with decreased plasma protein binding of phenytoin. The in vivo differences between pregnant and nonpregnant rats with respect to phenytoin binding in plasma are not due to differences in fatty acid concentrations, but the in vitro differences are due primarily to corresponding differences in free fatty acid concentrations if extensive in vitro lipolysis occurs.