Ibuprofen (CAS 15687-27-1) is widely used in painful situations and, usually, is administered in the racemic form. Since enantiomers may exert different pharmacodinamic and pharmacokinetic effects, the pharmaceutical industry has placed new emphasis on the preparation of new formulations of enantiomerically pure drugs that must be pharmacokinetically characterised prior to their administration in human beings. In this study, the absorption kinetics of two topical formulations of S(+)ibuprofen in rabbits was investigated. The S(+)ibuprofen levels in rabbit plasma were determined by a non-chiral HPLC method, whereas the absence of the R(-)ibuprofen enantiomer in plasma was confirmed by a chiral HPLC method. The results showed that S(+)ibuprofen was absorbed through the rabbit skin upon administration and the obtained levels varied with the formulation.

The objective of the present study has been to advance knowledge of the gastric role played by the amino acid L-Arginine (L-Arg) in the evolution of a chronic gastric ulcer. In order to clarify it, L-Arg alone or together with Ibuprofen have been administrated in an experimental acetic acid chronic ulcer, analysing characteristic parameters of an active curative process, such as PGE2 production, COX expression, and also angiogenesis, proliferation/apoptosis and growth factors expression. Our results reveal that L-Arg is favourable in the healing process improving the curative course. Ibuprofen caused a delay in ulcer healing, more evident 14 days after ulcer induction; COX-2 expression was increased at the 7th day although no signal of protein could be detected after 14 days; PGE2 production was inhibited in intact and ulcerated areas at both times assayed. In contrast, treatment with L-Arg reduced the delay of the lesion, the increment in COX-2 expression induced by Ibuprofen, and was able to maintain PGE2 levels similar to the control group after 14 days. Additionally, the histological study showed that the healing effects of L-Arg might be associated with an increased angiogenesis and FGF-2 expression. These actions could be considered key factors in the healing response associated with L-Arg administration. However, the proliferation study assayed with the PCNA-immunostaining method did not reveal significant differences, as the same as the apoptosis analysis. In conclusion, the coupling of L-Arg to Ibuprofen is an attractive alternative to Ibuprofen administration alone because it not only attenuates but also improves the evolution of chronic lesions through mechanisms that implicate endogenous PG and FGF-2-associated pathways, which allow an increase of angiogenesis process.

It has been proposed that neutrophil and oxygen dependent microvascular injuries may be important prime events in gastrointestinal (GI) toxicity of non-steroidal antiinflammatory drugs (NSAIDs). L-arginine (L-ARG) is an essential amino acid which participates in many important biochemical reactions associated to the normal physiology of the organism. In these experimentations, we studied the role of L-ARG, aminoacid precursor of NO synthesis, on ibuprofen (IB) induced gastric lesions, and also on the inflammatory and oxidative mechanisms related to mucosal damage. Oral administration of IB (100 mg kg(-1)), produced severe damage on gastric mucosa, which was more important after 6 h test-period, and was accompanied by a significant increment in myeloperoxidase (MPO) activity, as index of neutrophil activation, as well as lipid peroxidation (LP) levels and xanthine oxidase (XO) activity. However, no changes were observed in total mucosal glutathione (tGSH), nor glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activity. Simultaneous treatment with equimolar doses of L-ARG (oral and i.p.), considerably reduced the number and intensity of lesions, and at the same time (6 h) the maximum protection was also observed. In addition, L-ARG inhibited the IB-induced LP and XO enhancement, but did not produce changes in leukocyte infiltration, tGSH, GSH-Px and SOD activity. These findings suggest that (1) L-ARG protective effect on gastric mucosa against IB-induced mucosal lesions could be explained by a local effect and also might be due to the systemic action of the aminoacid; (2) the active oxygen species, derived both from XO and activated neutrophils, could play a role in the pathogenesis of gastric injury induced by IB, (3) L-ARG exhibit a protective effect against IB-induced mucosal damage, probably through the inhibition of oxidative stress derived via xanthine-XO, but it does not block the oxygen free radical production through polymorphe nuclear leukocytes.

We have recently reported the expression of COX-2 mRNA in the rat stomach after administration of indomethacin or SC-560, a selective COX-1 inhibitor, and suggested that this may be a reason why inhibition of both COX-1 and COX-2 is required for gastric ulcerogenic action of NSAID.In the present study, we investigated the functional mechanism for COX-2 expression in the rat stomach under COX-1 inhibition.Methods: Male SD rats were used after 18 h fasting.The animals were given indomethacin (30 mg/kg), SC-560 (30 mg/kg), rofecoxib (30 mg/kg) or SC-560 plus rofecoxib PO, and the gastric mucosa was examined 8 h later.Atropine (1 mg/kg) or omeprazole (60 mg/kg) was given SC 30 rain before indomethacin or 5C-560 plus rofecoxib.Gastric motility was determined by a balloon method.Mucosal PGE2 content was measured by EIA, while COX-2 mRNA was examined by RT-PCR.Results: lndomethacin decreased the mucosal PGE2 content and produced gross damage in the stomach with a marked gastric hypermotility.SC-560 alone caused a decrease in the PGE2 content and an increase in gastric motility but did not produce any damage in the stomach.However, SC-560 plus rofecoxib produced gastric hypermotility and gross lesions in the stomach, similar to indomethacin.Rofecoxib alone did not cause damage in the mucosa with no effect on gastric motility and PGE2 content.Gastric lesions induced by indomethacin were prevented by both atropine and omeprazole, although the hypermotility response was inhibited only by atropine.COX-2 mRNA was expressed in the gastric mucosa 4 h after indomethacin or SC-560 but not rofecoxib.The COX-2 expression induced by indomethacin was inhibited by atropine, even in the presence of exogenous HCI, while omeprazole had no effect.SC-560 markedly decreased the mucosal PGE2 content at 2 h after the administration, but this effect was significantly reverted 8 h later, in a rofecoxib or atropine but not omeprazole-senstive manner.Conclusion: These results confirmed the COX-2 expression in the stomach after administration of IM or SC-560, and further suggested that this process is associated with gastric hypermonhty response induced by COX-1 inhibition by these agents.Luminal acid does not play a role in the up-regulation of COX-2 in the, stomach under inhibition of COX-1.

AIM:Lercanidipine, a long-acting dihydropyridine with a good antihypertensive efficacy and tolerability in clinical use. With the aim to determine the efficacy and tolerability of this drug in usual clinical practice we performed the ELYPSE trial. METHODS:Grade 1 or 2 essential hypertensive patients in whom their physicians considered to prescribe a dihydropyridine were conferred to Lercanidipine 10 mg once daily with a 3-month follow-up; 9059 patients were included (age: 63 +/- 11 years; 58% women, 60% over 60 years, 56% grade 2 hypertensives and 69% previously treated with other antihypertensive drugs). A subgroup of 1267 patients (14%) who were included in the study had experienced adverse reactions with other drugs. Electronic case-report forms and a central database (Internet) were used in this trial. RESULTS:At baseline, blood pressure (BP) was 160.1 +/- 10.2/95.6 +/- 6.6 mmHg; and heart rate (HR) 77.3 +/- 9.3 beats/min. Significant reductions in both systolic and diastolic BP were attained at 1 month with slight additional decreases 2 months later. At 3 months, BP was 141.4 +/- 11.3/ 83.1 +/- 6.9 mmHg, and HR 75.2 +/- 8.2 beats/min (p < 0.001 versus baseline). At the study end. 64% of the patients achieved a diastolic BP < 90 mmHg, BP control (< 140/90 mmHg) was attained in 32%. In the subgroup of diabetics (n = 1269) an adequate BP control (< 130/85) was attained in only 16.4%. The overall incidence of adverse events was 6.5%, of which the most frequent were headache (2.9%), ankle oedema (1.2%), flushing (1.1%) and palpitations (0.6%). Withdrawal rate was < 1%. The efficacy and tolerability in the subgroup of patients included in the study due to adverse events with other drugs were similar to the whole study group. CONCLUSION:In this study Lercanidipine has shown a good efficacy and tolerability in daily clinical practice. These findings are concordant with those reported in randomized controlled trials.

Antioxidant therapy may be useful in diseases with impaired oxidant-antioxidant balance such as pulmonary fibrosis. This study examines the effect of N-acetylcysteine (NAC) on bleomycin-induced lung fibrosis in rats. NAC (3 mmol x kg(-1); oral) was given daily from 1 week prior to a single intratracheal instillation of bleomycin (2.5 U x kg(-1)) or saline, until 14 days postinstillation. NAC partially decreased the augmented collagen deposition in bleomycin-exposed rats (hydroxyproline content was 4,354+/-386 and 3,416+/-326 microg x lung(-1) in vehicle-treated and NAC-treated rats, respectively; p < 0.05). The histological assessment using a semiquantitative score showed less collagen deposition and inflammatory cells in NAC-treated rats compared to those receiving bleomycin alone. NAC failed to inhibit the bleomycin-induced increases in lung wet weight and in cell counts and protein levels of bronchoalveolar lavage fluid, but significantly increased total glutathione and taurine levels in bronchoalveolar lavage fluid. These results indicate that oral N-acetylcysteine improves the pulmonary antioxidant protection and may be useful in reducing lung damage produced by bleomycin.

Introduction: Oesophageal manometry and 24hr pH studies are used to assess patients with symptoms of GORD and non-mechanical dysphagia.After investigation patients may not commence therapy until review in the out patient clinic which may involve a variable delay.Aim: To assess the role of the orphysiology technician in data analysis and administration of therapy directly from written protocol.Method: Patients with GORD+/non mechanical dysphagia underwent oesophageal manometry and pH studies.Therapy was administered directly from the GI physiology laboratory and consisted of Cisapride (C) 20mg BD for oesophageal dysmotility and normal pH values, or C and Lansoprazole (L)30mg daily for oesophageal dysmotility and abnormal pH study.Therapy was given for a 2-week period.Patients then underwent repeat studies on medication to monitor clinical, symptomatic and physiological responses, after which they had out patient review by a consultant.Results: 38 patients underwent testing and primary therapy (25M: 13F age range 24-76 years), 17 were treated with C and 21 with C and L, and symptoms and physiological responses shown.Conclusions: The Gl physiology technician was capable of data analysis and therapy administration from protocol.This administration minimised delays in treatment, and provided clinical and physiological data pre and post therapy without delaying the patients consultant review.C Patients' responses C&L 10 asymptomatic and improved physiology 16 4 symptoms same-improved physiology 2 1 symptoms same -deteriorating physiology

Lercanidipine is a novel lipophilic calcium channel blocker (CCB) that has exhibited a good antihypertensive efficacy and an excellent tolerability in randomized clinical trials. But, as it has been noted, daily clinical practice sometimes differ to randomized clinical trials. Thus, with the aim to investigate the profile of this new antihypertensive agent we designed a study called ELYPSE. ELYPSE is a multicenter surveillance trial to analyze the efficacy and tolerability of Lercanidipine in clinical practice. Essential hypertensives, candidates to be treated with Lercanidipine are confered to this drug (10/20 mg od) during a 6-month follow up. Blood pressure and presence of adverse effects are determined at 1, 3 and 6 months. We present the preliminary results of the first 3 month follow up. To date, 7469 patients have been included (40% males, age 63 ± 19 years). 62% are grade 2 hypertensives. 36% were untreated and 64% previously treated. Among the treated patients, 971 (13%) were included in the study due to adverse effects (AEs) with other drugs. Mean blood pressure (BP) at baseline was: 162.1/96.9 mmHg. At 3-month follow up: 141.8/83.8 mmHg. Only 542 (7%) patients exhibited AEs. The most frequent AEs have been headache (2.7%) and ankle oedema (1.1%), the others (tachycardia, flushing …) are <1%. Lercanidipine has demonstrated to be an effective antihypertensive agent with an excellent tolerability in daily clinical practice. It is remarkable the very low incidence of the typical CCB-related AEs observed with this drug. These data confirm the results of randomized trials and support the potential benefit of this drug in terms of compliance in clinical practice.

We examined the in vitro effects of tert-butylhydroperoxide (tBu-OOH) in human bronchial muscle. tert-Butylhydroperoxide produced concentration-dependent contractions of bronchial rings (maximum effect was 56.5 +/- 9.6% of contraction by 1 mM acetylcholine; effective concentration 50% was approximately 100 microM). tert-Butylhydroperoxide (0.5 mM)-induced contraction was enhanced by epithelial removal but abolished by indomethacin (cyclooxygenase inhibitor) and zileuton (lipoxygenase inhibitor). tert-Butylhydroperoxide produced a transient rise in intracellular calcium in human cultured airway smooth muscle cells (HCASMC). The bronchial reactivity to acetylcholine and histamine was not altered by tBu-OOH. In HCASMC, tBu-OOH (0.5 mM, 30 min) increased malondialdehyde levels (MDA; from 7.80 +/- 0.83 to 26.82 +/- 1.49 nmol mg(-1) protein), accompanied by a decrease of reduced glutathione (GSH; from 16.7 +/- 2.6 to 6.9 +/- 1.9 nmol mg(-1) protein) and an increase of oxidized glutathione (from 0.09 +/- 0.03 to 0.18 +/- 0.03 nmol mg(-1) protein). N-acetylcysteine (0.3 mM) inhibited by approximately 60% the bronchial contraction resulting from tBu-OOH (0.5 mM) and protected cultured cells exposed to tBu-OOH (MDA was lowered to 19.51 +/- 1.19 nmol mg(-1) protein, and GSH content was replenished). In summary, tBu-OOH caused contraction of human bronchial muscle mediated by release of cyclo-oxygenase and lipoxygenase products without producing airways hyperreactivity. N-acetylcysteine decreases tBu-OOH-induced contraction and protects human cultured airway smooth muscle cells exposed to tBu-OOH.

Sodium diclofenac (DCF, CAS 1507-79-6) is a non-steroidal anti-inflammatory drug whose activity is mainly due to an inhibitory effect on the synthesis of the prostaglandins. At present, a tendency towards its topical use in the treatment of the inflammatory state of the anterior segment of the eye as an alternative to the steroid drugs is observed. The pharmacokinetics of DCF was studied in rabbits by assessing the ocular and systemic absorption of DCF after administering DCF eye drops. The chromatographic methods available were not sensitive enough to quantify the extremely low drug concentrations which appeared in the biological fluids after ocular treatment. For this reason, the concentrations of DCF in plasma and aqueous humor were evaluated by a coupled liquid chromatography/gas chromatography (LC/GC) method. DCF was absorbed well through the cornea with the aqueous humor concentration peak being 757.8 ng/ml at 120 min. This good ocular absorption of DCF was confirmed by the concentrations observed in plasma. The presence of tramazoline (TMZ, CAS 74195-73-6) in the eye drops increases the levels of DCF in aqueous humor.

The basal peroxide production and the oxidative burst induced by phagocytosis of opsonized E. coli was studied by flow cytometry using dihydrorhodamine 123. The human leukocytes were incubated in the absence and presence of N-acetylcysteine. The oxidative response to the phagocytosis of bacteria differed among cell populations. Thus, 90% of granulocytes and 50% of monocytes showed an oxidative burst in response to opsonized bacteria while less than 1% of lymphocytes showed a fluorescence signal. N-Acetylcysteine (4.7, 9.5, 19, 38 or 76 mM) produced a dose-dependent inhibition of the oxidative response to phagocytosis in the three cellular populations reaching almost complete inhibition for 76 mM. This protective effect of N-acetylcysteine against oxidative stress in leukocytes was obtained without cytotoxicity (assessed by flow cytometry with staining with propidium iodide) or changes in the pH of the medium. These results give further support to the antioxidant effect of N-acetylcysteine in human peripheral blood cells.

It has been suggested that reactive oxygen species released by activated polymorphonuclear leukocytes (PMN) in man is one mechanism of tissue injury. Therapeutic action aimed at increasing antioxidant defence mechanisms is still a clinical challenge. This study examines the activity of N-acetylcysteine, a known antioxidant, in the protection of PMN exposed in-vitro to the chemoattractant peptide fMet-Leu-Phe (FMLP), the protein kinase C activator phorbol myristate acetate or the lipid peroxidation promoter t-butyl hydroperoxide.FMLP (3-300 nM) and phorbol myristate acetate (160 pm-160 nM) induced concentration-related superoxide anion generation. Pre-treatment with N-acetylcysteine (33-333 mu M) resulted in concentration-related inhibition of superoxide production induced by FMLP (30 nM) or phorbol myristate acetate (16 nM); -log IC50 values were 3.97 +/- 0.07 and 3.91 +/- 0.10, respectively. Changes in intracellular calcium ion concentration ([Ca2+](i)) induced by FMLP (30 nM) were studied in fura-2-loaded human PMN. FMLP produced a transient calcium response, i.e. a peak followed by decay to a residual value above baseline. N-Acetylcysteine (333 mu M) did not affect either basal [Ca2+](i) values or changes in [Ca2+](i) values after treatment with FMLP. Activation by phorbol myristate acetate caused a reduction in glutathione levels from 5.94 +/- 0.86 (control) to 1.84 +/- 0.51 nmol/3 x 10(6) cells (P<0.05 compared with control). Pre-treatment with N-acetylcysteine (333 mu M) fully reversed the reduction in glutathione levels induced by phorbol myristate acetate (4.83 +/- 0.68 nmol/3 x 10(6) cells; P>0.05 compared with control). Exposure to t-butyl hydroperoxide (0.5 mM, 30 min) markedly increased malondialdehyde levels (from 0.03 +/- 0.02 to 0.73 +/- 0.07 nmol/10(6) cells), and index of lipid peroxidation. Malondialdehyde levels were significantly reduced in PMN treated with N-acetylcysteine (333 mu M; 0.55 +/- 0.04 nmol/10(6) cells; P<0.05 compared with untreated cells exposed to t-butyl hydroperoxide).In conclusion, N-acetylcysteine reduces superoxide generation in response to FMLP and phorbol myristate acetate and partially protects against lipid peroxidation in PMN from man. The protection afforded by N-acetylcysteine is not related to alteration of the intracellular calcium signal but might be effected by replenishment of the intracellular glutathione levels.

Mitochondria may be primary targets of free radical damage associated with aging. We have found that mitochondrial glutathione is markedly oxidized with aging in rats and mice. The oxidized to reduced glutathione ratio rises with aging in the liver, kidney, and brain. The magnitude of these changes is much higher than that previously found in whole cells of any species previously studied. In the liver, this ratio (expressing GSSG as a percent of GSH) changed from 0.77 +/- 0.19% (n=5) in young rats to 2.47 +/- 1.25% (n=5) in old ones, i.e., 320% of the controls. In the brain and kidney, values for old rats were, respectively, 600 and 540% higher than those of young rats. A marked oxidation of mitochondrial glutathione also occurred in mice. Aging also caused an increase in 8-oxo-7,8-dihydro-2'-deoxyguanosine levels in mtDNA in rats and mice. Oral antioxidant administration protected against both glutathione oxidation and mtDNA damage in rats and mice. Finally, we have found a direct relationship between mtDNA damage and mitochondrial glutathione oxidation. This occurs both in rats (r=0.95) and in mice (r=0.98). This relationship, which has been observed for the first time in these studies, underscores the role of glutathione in the protection against free radical damage that occurs upon aging.

The pharmacokinetics of thymoxamine hydrochloride were studied in rabbits by the assessment of its ocular and systemic absorption after instillation of thymoxamine hydrochloride 0.5% eye drops. Plasma levels were compared with those observed after i.v. bolus administration of thymoxamine hydrochloride at 2.5 mg/kg. Deacetylthymoxamine is the main metabolite of thymoxamine, generated by esterase hydrolysis. It was evaluated, as an indication of the parent drug, in aqueous humor and plasma by an HPLC method with fluorescence detection (detection limit = 5 ng/ml). Thymoxamine was found to permeate the cornea and to be hydrolysed very quickly, showing very good absorption with a maximum aqueous humor concentration of deacetylthymoxamine of 2329 ng/ml 15 min after eye drop instillation. The study of the systemic absorption of thymoxamine allowed the exclusion of the possibility of systemic side effects following ocular treatment. In fact, considering the detection limit of the method, the plasma levels of deacetylthymoxamine are certainly more than 100-times lower than those observed with intravenous treatment.

The ocular pharmacokinetics of thiamphenicol (TAP, CAS 15318-45-3) was studied in rabbits by means of the assessment of its ocular and systemic absorption, and urinary excretion after instillation of 0.5% TAP eye drops. TAP concentrations in aqueous humor, plasma and urine were evaluated by a coupled LC/GC method (detection limit = 0.1 ng/ml), because the necessity to have a technique much more sensitive than the traditional chromatographic ones available in order to quantify the very low drug concentrations in biological fluids produced by the ocular treatment, and generally by a topical administration. The intravenous route was chosen as reference and allowed the absolute bioavailability to be estimated. TAP proved to be well absorbed through the cornea with the peak aqueous humor concentration of 110 ng/ml at 45 min following the instillation. The good ocular absorption of TAP was confirmed by the plasma concentrations observed after instillation of 0.5% eye drops. In any case, these concentrations were more than 1000 times lower than those observed after the intravenous treatment at the dose normally used for infectious diseases, allowing to exclude any systemic toxicity of TAP eye drops. The absolute ocular bioavailability was 16.2% when estimated from the AUC values and 34.0% from the cumulative urinary excretion values.

The free radical theory of aging suggests that oxygen free radicals may be involved in the aging process. Thus, changes in antioxidant mechanisms may occur with aging. Since glutathione is one of the most effective antioxidant systems in the cell, its metabolism may change with aging. In this chapter we describe experiments which show the involvement of glutathione in the aging process and which provide a rationale for the administration of antioxidants to old organisms to protect them against some of the changes that occur with aging.

Metadoxine (pyridoxine-pyrrolidone carboxylate) has been reported to accelerate ethanol metabolism. In the present work we have investigated the effect of metadoxine on the activities of isolated alcohol and aldehyde dehydrogenases from rat and man, and on the activity of these enzymes in chronic ethanol-fed rats. Our results indicate that in vitro metadoxine does not activate any of the enzymatic forms of alcohol dehydrogenase (classes I and II) or aldehyde dehydrogenase (low-Km and high-Km, cytosolic and mitochondrial). At concentrations higher than 0.1 mM, metadoxine inhibits rat class II alcohol dehydrogenase, although this would probably not affect the physiological ethanol metabolism. Chronic ethanol intake for 5 weeks results in a 25% decrease of rat hepatic alcohol dehydrogenase (class I) activity as compared with the pair-fed controls. The simultaneous treatment with metadoxine prevents activity loss, suggesting that the positive effect of metadoxine on ethanol metabolism can be explained by the maintenance of normal levels of alcohol dehydrogenase during chronic ethanol intake. No specific effect of chronic exposure to ethanol or to metadoxine was detected on rat aldehyde dehydrogenase activity.