Pharmacological implications in the switch from acute to chronic inflammation

Resolution or persistence of the inflammatory response strictly reflects the dynamic balance between two major determinants: (1) the recruitment of circulating inflammatory cells together with the proliferation of resident cells and (2) the death, or apoptosis, of cells accumulated locally. The link between these two determinants seems to be represented by the incapacity of monocytes and macrophages to switch off activation of inflammation, thereby acting as a major promoter of the inappropriate recruitment, retention and survival of activated cells at inflamed tissue sites. Various pathways contribute to the persistent macrophage activation and, therefore, represent major rational targets for biologic approaches aimed at controlling the evolution of inflammation. These pathways include the continuous recruitment of Th1 cells into inflamed tissues, the subnormal production of anti-inflammatory IL-10 by regulatory T cells and macrophages, the reduced release of adenosine by endothelial cells and fibroblasts, the reduced production of soluble decoy receptors for TNF by macrophages and the reduced local availability of the anti-inflammatory cytokine IL-1 receptor antagonist. Moreover, the persistent activation and the survival of inflammatory cells strictly depends on the activity of the NF-B system, which is responsible for inducing the synthesis of proinflammatory mediators in inflammatory cells such as monocytes, macrophages, fibroblasts and endothelial cells. It is of note that the activity of the NF-B system can be inhibited by several drugs such as corticosteroids, leflunomide, cyclosporin A, tacrolimus, high concentrations of sulphasalazine and aspirin, and concentrations of oxaprozin achievable in vivo. Consequently, the possibility of controlling the NF-B system pharmacologically raises opportunities for developing approaches to interfere with the transformation of transient to persistent inflammatory responses.     

Pharmacological action of melatonin in shock, inflammation and ischemia/reperfusion injury

Phosphodiesterase 5 terminates the cellular actions of the second messenger molecule cyclic GMP; inhibitors of phosphodiesterase 5 will therefore increase and prolong the actions of endogenous substances that signal via the cyclic GMP pathway, including nitric oxide released as a neurotransmitter from nitrergic nerves. To date, the most widely used phosphodiesterase 5 inhibitors, zaprinast and sildenafil, have proved vital in the elucidation of the widespread role of cyclic GMP in nitrergic transmission and, specifically in the case of sildenafil, have provided a major breakthrough in the treatment of erectile dysfunction in men. Although still a matter of debate, early evidence indicates that sildenafil may also be of benefit in some forms of sexual dysfunction in women. The remarkable clinical success of sildenafil has prompted the search for further novel phosphodiesterase 5 inhibitors which might be used to enhance nitrergic function in other disease states.     

Pharmacological strategies to resolve acute inflammation

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Protective effect of melatonin in carrageenan-induced acute local inflammation.

The aim of the present study was to investigate the protective effect of the pineal hormone melatonin in a model of acute local inflammation (carrageenan-induced paw oedema). Inflammation was assessed by measurement of nitric oxide (NO), Malondialdehyde (MDA) and glutathione levels in the paw tissue in rats. The intraplantar injection of carrageenan elicited an inflammatory response that was characterised by a time-dependent increase in paw oedema, increased level of nitrite/nitrate and MDA, a lipid peroxidation product and decreased glutathione levels in the paw tissue. The maximal increase in paw volume was observed at 4h after administration (maximal in paw volume 160+/-3.34 ml). In addition, NO level and MDA were markedly increased in the carrageenan-treated paw (59.96+/-6.58 and 19.33+/-3.35 micromol g(-1), respectively), versus in the control paw glutathione level decreased in paw tissue (3.24+/-0.24 micromol g(-1)). However, carrageenan-induced paw oedema was significantly reduced in a dose-dependent manner by treatment with melatonin (given at 5 and 10 mg kg(-1)) at 1, 2, 3, 4, 5 and 6h after injection of carrageenan. Melatonin treatment also caused a significant reduction of the NO and MDA levels, while increasing glutathione level in the paw tissue. Our findings support the view that melatonin exerts anti-inflammatory effects. Part of these anti-inflammatory effect may be related to an inhibition of the NO and MDA production, while another part may be related to increase of the glutathione level in the paw tissue.     

Pharmacological investigation of acute cellular accumulation in immunological air pouch inflammation

Immunologically-mediated cellular accumulation was measured 24 hours after antigenic challenge using a rat subcutaneous air pouch model. This response was inhibited by treatment with prednisolone, colchicine, anti-thymocyte serum and systemic antigen. In contrast, administration of a range of other pharmacological and clinically active agents had little effect. The profile of inhibitory activity suggested that this response was mainly due to delayed type hypersensitivity with little anaphylactic or Arthus-type component.     

Pharmacological actions of cannabinoids

Mammalian tissues express at least two types of cannabinoid receptor, CB1 and CB2, both G protein coupled. CB1 receptors are expressed predominantly at nerve terminals where they mediate inhibition of transmitter release. CB2 receptors are found mainly on immune cells, one of their roles being to modulate cytokine release. Endogenous ligands for these receptors (endocannabinoids) also exist. These are all eicosanoids; prominent examples include arachidonoylethanolamide (anandamide) and 2-arachidonoyl glycerol. These discoveries have led to the development of CB1- and CB2-selective agonists and antagonists and of bioassays for characterizing such ligands. Cannabinoid receptor antagonists include the CB1-selective SR141716A, AM251, AM281 and LY320135, and the CB2-selective SR144528 and AM630. These all behave as inverse agonists, one indication that CB1 and CB2 receptors can exist in a constitutively active state. Neutral cannabinoid receptor antagonists that seem to lack inverse agonist properties have recently also been developed. As well as acting on CB1 and CB2 receptors, there is convincing evidence that anandamide can activate transient receptor potential vanilloid type 1 (TRPV1) receptors. Certain cannabinoids also appear to have non-CB1, non-CB2, non-TRPV1 targets, for example CB2-like receptors that can mediate antinociception and "abnormal-cannabidiol" receptors that mediate vasorelaxation and promote microglial cell migration. There is evidence too for TRPV1-like receptors on glutamatergic neurons, for alpha2-adrenoceptor-like (imidazoline) receptors at sympathetic nerve terminals, for novel G protein-coupled receptors for R-(+)-WIN55212 and anandamide in the brain and spinal cord, for novel receptors for delta9-tetrahydrocannabinol and cannabinol on perivascular sensory nerves and for novel anandamide receptors in the gastro-intestinal tract. The presence of allosteric sites for cannabinoids on various ion channels and non-cannabinoid receptors has also been proposed. In addition, more information is beginning to emerge about the pharmacological actions of the non-psychoactive plant cannabinoid, cannabidiol. These recent advances in cannabinoid pharmacology are all discussed in this review.     

Pharmacological actions of pepsitensin

In confirmation of the results of Croxatto and his co-workers, plasma proteins incubated with pepsin yielded a substance (pepsitensin) with pressor activity. Euglobulin gave a much higher yield than the other plasma protein fractions. Incubation for 4 hr at pH 4 gave high yields of pressor activity (pepsitensin) but no antidiuretic activity; incubation of euglobulin for 4 hr at pH 2.5 yielded extracts with antidiuretic as well as pressor activity. Incubation for 8 to 11 hr at pH 2.5 produced the highest yield of both activities. Further incubation, at the same pH, up to 20 hr caused a rapid decline in the pressor activity of the extracts, but the antidiuretic activity was much more resistant to destruction by pepsin. Pepsitensin was found to be very soluble in water and poorly soluble in organic solvents. It is not inactivated by thioglycollate. In blood pressure assays some animals did not respond to pepsitensin, and nephrectomized (17 to 24 hr) rats were found to be more suitable preparations. Pepsitensin was shown to exert pressor effect by direct action on the blood vessels. Its pressor action could be differentiated from that of tyramine, dimethylphenylpiperazine, nicotine, noradrenaline and Pitressin but not from that of angiotensin. The isolated guinea-pig ileum and the rat uterus were equally sensitive to angiotensin and pepsitensin. In paper chromatograms, in the solvent system butanol-acetic acid-water, the R_F of pepsitensin was very similar to that of angiotensin.     

Immunosuppressive actions of prostaglandins and the possible increase in chronic inflammation after cyclo-oxygenase inhibitors

A method is described to examine the activity of potential antirheumatic drugs on the release and activity of lymphokines and interleukins in vitro, using human peripheral blood mononuclear cells and synovial cells. The enhancement of lymphocyte-mediated effects brought about by non-steroid anti-inflammatory drugs has been shown to be the result of inhibition of a prostaglandin negative-feedback mechanism. Since the underlying features of rheumatoid arthritis and related diseases are almost certainly brought about by mononuclear cell activation, their enhancement by non-steroid anti-inflammatory drugs might well have serious clinical implications. The possibility is discussed that aspirin-like drugs, administered in large doses to patients suffering slight joint pain, might well exacerbate, perpetuate or even initiate a chronic arthritic condition. We suggest that, as soon as the disease has been diagnosed, patients should be treated with a disease-modifying drug and, if necessary, an analgesic which does not inhibit cyclo-oxygenase.     

慢性阻塞性肺疾病急性加重期的药物治疗

慢性阻塞性肺疾病（COPD）是一种全球性的常见疾病。居主要致死性疾病的第4位,在未来的几十年内,COPD的发生率和死亡率还将进一步增加。由于COPD患病率高、反复出现病情加重、病程呈持续进展,该病所造成的社会经济负担巨大。1996年英国用于COPD的花费为40亿美元,而美国在1993年就已达230亿美元。     

利福昔明的药理作用和临床应用

利福昔明(rifaximi,n商品名希捷)系利福霉素SV的半合成衍生物,为广谱肠道抗生素。该药由意大利阿尔法公司研制开发,1987年作为抗感染性腹泻药物在意大利上市,之后在国外仍被广泛应用,2004年经SFDA批准已在我国临床应用。本文对利福昔明的药理作用、药代动力学及国内外临床应用情况作一介绍。利福昔明的结构式,见图1。化学名称:4-脱氧-4'-甲基吡啶[1',2'-1,2]咪唑并[5,4-环]利福霉素SV。分子式为C43H51N3O11,分子量为785.9。1药理作用1.1体外抗菌活性利福昔明的抗菌作用特点是抗菌谱广,抗菌活性强,对革兰阳性需氧菌中的金葡菌、表皮葡萄…     

Pharmacological actions and acute toxicity of methyl- and phenyl-3-methoxy-4-hydroxy styryl ketones

Some pharmacological actions and acute toxicity effects of methyl- and phenyl-3-methoxy-4-hydroxy styryl ketones have been described in experimental animals. The compounds antagonised the contractions evoked by a variety of agonists on several smooth muscle preparations in vitro. They produced inhibitory effects on spontaneously contracting uteri from pregnant rats and relaxant effects on pendular movements of rabbit duodenum and on dog intestinal movements in vivo. The compounds inhibited the castor oil induced diarrhoea in rat and propulsion of charcoal test meal in mice. Phenylbutazone showed similar effect on castor oil diarrhoea. The compounds failed to modify gestation period or parturition in pregnant rats. They antagonised bradykinin-induced bronchospasm in guinea pig. The compounds showed no significant effect on cardiovascular and respiratory systems: CNS and general behaviour were not affected even at high doses. Oral LD50 for both the compounds was greater than 2 g/kg.     

Pharmacological actions of pure muscarine chloride

The action of chromatographically pure crystalline muscarine chloride, prepared from Amanita muscaria, has been compared with acetylcholine chloride (ACh) on a number of different organs from a variety of species. Muscarine caused spasm in vivo and in vitro of muscles of the gut, uterus, urinary bladder, and bronchus. It also caused contraction of the horse ureter and carotid artery chain in vitro and slowed the isolated auricles of the guinea-pig and rabbit, and the frog heart.     

Pharmacological inhibition of leukotriene actions.

Leukotrienes represent a group of lipid mediators that play a very important role in a wide variety of pathological conditions. The presence of leukotrienes in inflammatory sites has been extensively documented, and accordingly research efforts have been directed towards the development of drugs that interfere with the formation or effects of leukotrienes. Although clinical application of such drugs has been disappointing in the past, recent discoveries of more potent and selective drugs seem to be promising. This review attempts to highlight some of these exciting developments.     

Molecular tools to study melatonin pathways and actions

Melatonin, an indoleamine neurohormone that is synthesized mainly in the pineal gland and derived from 5-HT, has many effects on a wide range of physio-pathological functions. Some of these effects are mediated by the interactions of melatonin with the two melatonin MT1 and MT2 receptors. Other effects are often suggested to be due to the chemical antioxidant nature of this indoleamine, and are observed at high, non-physiological concentrations. However, it is increasingly believed that some of these effects are due to interactions with other protein targets. In this review, we summarize the molecular pharmacology of melatonin, including the main enzymes involved in its synthesis and catabolism, and the proteins that mediate its actions. Furthermore, various compounds, mainly inhibitors and antagonists, that can be used to dissect these functions and pathways are presented.     

粉防己碱在炎症性肺部疾病中的药理作用

粉防己碱具有抗炎、抗变态反应、抗氧化、抗纤维化、抗血小板聚集和免疫调节等多方面的药理作用,已用于治疗矽肺,对哮喘和COPD继发的肺动脉高压也有明显的改善作用。     

Pharmacological actions of sodium ferulate in cardiovascular system

Sodium ferulate (SF) or 3-methoxy-4-hydroxy-cinamate sodium is an active principle from Angelica sinensis, Cimicifuga heracleifolia, Lignsticum chuangxiong, and other plants. It has been used in traditional Chinese medicine and is approved by State Drugs Administration of China as a drug for treatment of cardiovascular and cerebrovascular diseases. SF has antithrombotic, platelet aggregation inhibitory and antioxidant activities in animals and humans. For several decades SF has been widely used in China to treat cardiovascular and cerebrovascular diseases and to prevent thrombosis. Exciting clinical results have been obtained with SF in coronary heart disease, atherosclerosis, pulmonary heart disease and thrombosis. Its safety and efficacy have been demonstrated in clinical practice. This article briefly reviews basic pharmacology, pharmacokinetics, toxicology and clinical pharmacology of SF. The in vitro and in vivo data support the view that SF is a useful drug for the treatment of cardiovascular diseases.