dinoprost and pimagedine

Infections with a strain of Escherichia coli producing Shiga toxins could be one of the causes of fetal morbidity and mortality in pregnant women. We have previously reported that Shiga toxin type 2 (Stx2) induces preterm delivery in pregnant rats. In this study, we evaluate the role of TNF-α, PGs and NO in the Stx2-induced preterm delivery.. Pregnant rats were treated with Stx2 (0.7 ng g(-1)) and killed at different times after treatment. Placenta and decidua were used to analyse NOS activity by the conversion of L-[(14)C]arginine into L-[(14)C]citrulline, levels of PGE(2) and PGF(2α) assessed by radioimmunoassay, and cyclooxygenase (COX) proteins by Western blot. TNF-α level was analysed in serum by ELISA and by cytotoxicity in L929 cells. The inhibitor of inducible NOS, aminoguanidine, the COX-2 inhibitor, meloxicam, and the competitive inhibitor of TNF-α, etanercept, were used alone or combined to inhibit NO, PGs and TNF-α production respectively, to prevent Stx2-induced preterm delivery.. Stx2 increased placental PGE(2) and decidual PGF(2α) levels as well as COX-2 expression in both tissues. Aminoguanidine and meloxicam delayed the preterm delivery time but did not prevent it. Etanercept blocked the TNF-α increase after Stx2 treatment and reduced the preterm delivery by approximately 30%. The combined action of aminoguanidine and etanercept prevented Stx2-induced preterm delivery by roughly 70%.. Our results demonstrate that the increased TNF-α and NO induced by Stx2 were the predominant factors responsible for preterm delivery in rats.

Topics: Animals; Cyclooxygenase 2; Decidua; Dinoprost; Dinoprostone; Drug Therapy, Combination; Etanercept; Female; Guanidines; Immunoglobulin G; Nitric Oxide; Placenta; Pregnancy; Premature Birth; Rats; Rats, Sprague-Dawley; Receptors, Tumor Necrosis Factor; Shiga Toxin 2; Tumor Necrosis Factor-alpha

Advanced glycation end products (AGEs) are produced by glycoxidation and lipid peroxidation. AGEs induce oxidative stress and inflammation, and accumulate in tubular cells after kidney transplantation. We hypothesize that the AGE formation blocker aminoguanidine (AG) reduces AGE formation and improves renal transplant function.. Fisher 344 kidneys were orthotopically transplanted into Lewis recipients. Recipients were treated with AG (100 mg/kg/day), candesartan (CAND; 5mg/kg/day), or vehicle (VEH) for 24 weeks. The major non-cross linking AGE N(ε)-carboxymethyllysine (CML) was measured post-transplantation with gas chromatography-tandem mass spectrometry or immunohistochemistry. As a marker of systemic lipid peroxidation 8-isoprostane was measured by ELISA. We determined intra-arterial blood pressure, heart weight/body weight ratio, size of cardiomyocytes and cardiac hypertrophy as assessed by echocardiography. For biochemical evaluation of cardiac and renal fibrosis we measured hydroxyproline content.. AG significantly reduced serum CML and 8-isoprostane, but did not reduce signs of chronic allograft nephropathy (CAN) or blood pressure. AG did not alter tubular AGE accumulation. AG reduced heart weight/body weight ratio (AG: 2.7 ± 0.1g/kg; CAND: 2.2 ± 0.1, VEH: 3.0 ± 0.4 g/kg), size of cardiomyocytes (P < 0.05) and showed a tendency to reduce cardiac hypertrophy (wall volume average radial AG 7.072 ± 0.83 cm(3) vs. CAND 6.841 ± 0.66 cm(3) vs. VEH 7.839 ± 0.74 cm(3)).. Despite effective reduction of serum CML and 8-isoprostane, AG did not ameliorate CAN or reduce renal AGE accumulation. On the other hand AG reduced cardiac size suggesting a supportive cardio-protective action which is blood pressure independent.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Benzimidazoles; Biphenyl Compounds; Cardiotonic Agents; Dinoprost; Enzyme Inhibitors; Glycation End Products, Advanced; Guanidines; Hydroxyproline; Kidney Diseases; Kidney Function Tests; Kidney Transplantation; Lysine; Male; Oxidative Stress; Proteinuria; Rats; Rats, Inbred F344; Rats, Inbred Lew; Tetrazoles; Time Factors; Transplantation, Homologous

Maternal infections are one of the main causes of adverse developmental outcomes including embryonic resorption and preterm labour. In this study a mouse model of inflammation-associated preterm delivery was developed, and used to study the relationship between nitric oxide (NO) and prostaglandins (PGs).. The murine model of preterm labour was achieved by assaying different doses of bacterial lipopolysaccharides (LPS). Once established, it was used to analyse uterine levels of prostaglandins E(2) and F(2α) (by radioimmunoassay), cyclooxygenases (COX) and NOS proteins (by Western blot) and NO synthase (NOS) activity. Effects of inhibitors of COX and NOS on LPS-induced preterm labour were also studied. In vitro assays with a nitric oxide donor (SNAP) were performed to analyse the modulation of prostaglandin production by NO.. Lipopolysaccharide increased uterine NO and PG synthesis and induced preterm delivery. Co-administration of meloxicam, a cyclooxygenase-2 inhibitor, or aminoguanidine, an inducible NOS inhibitor, prevented LPS-induced preterm delivery and blocked the increase in PGs and NO. Notably, the levels of NO were found to determine its effect on PG synthesis; low concentrations of NO reduced PG synthesis whereas high concentrations augmented them.. An infection-associated model of preterm labour showed that preterm delivery can be prevented by decreasing PG or NO production. NO was found to have a dual effect on PG synthesis depending on its concentration. These data contribute to the understanding of the interaction between NO and PGs in pregnancy and parturition, and could help to improve neonatal outcomes.

Topics: Animals; Blotting, Western; Cyclooxygenase 2 Inhibitors; Dinoprost; Dinoprostone; Disease Models, Animal; Enzyme Inhibitors; Female; Guanidines; Inflammation; Lipopolysaccharides; Meloxicam; Mice; Mice, Inbred BALB C; Nitric Oxide; Nitric Oxide Synthase; Obstetric Labor, Premature; Pregnancy; Radioimmunoassay; Thiazines; Thiazoles; Uterus

The aim of our study was first to investigate if there exists an interaction between nitric oxide (NO) and prostaglandin (PG) generation in the estrogenized rat uterus challenged by lipopolysaccharide (LPS), and, secondly, which isoforms of nitric oxide synthase (NOS) and cyclooxygenase (COX) participate in this process.. To study the effect of LPS and to characterize the isoenzymes involved in the process, specific inhibitors of iNOS (aminoguanidine) and COX-II (meloxicam, nimesulide) and non-specific of COX (indomethacin) were injected intraperitoneally to determine their effect on NO and PG production, and on NOS and COX expression induced by LPS in estrogenized rat uterus. NO production was measured by arginine-citrulline conversion assay and PGE(2)/PGF(2alpha,)by radioconversion. Enzyme expression was evaluated by Western blot analysis.. The present work shows that iNOS inhibitor, aminoguanidine, reduced NO and PGE(2)/PGF(2alpha) production induced by LPS injection. Aminoguanidine exerts its effect over the PG metabolism by inhibiting COX-II activity and expression. On the other hand, both indomethacin, a non-selective PG inhibitor, and meloxicam, a COX-II inhibitor, stimulated NO production and reduced PGE(2)/PGF(2alpha) generation. Indomethacin also reduced COX-II and iNOS expression.. These results indicate that in the estrogenized rat uterus challenged with LPS, PG and NO interact affecting each other's metabolic pathways. The above findings indicate that the interaction between NOS and COX might be important in the regulation of physiopathologic events during pregnancy.

Topics: Animals; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprost; Dinoprostone; Down-Regulation; Embryo Loss; Estrogens; Female; Guanidines; Indomethacin; Inflammation; Isoenzymes; Lipopolysaccharides; Meloxicam; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Pregnancy; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Rats; Rats, Wistar; Sulfonamides; Thiazines; Thiazoles; Uterus

The contribution of nitric oxide (NO) to articular pain in arthritis induced by zymosan (1 mg, intra articular) in rats was assessed by measuring articular incapacitation (AI). Systemic treatment with the non-selective NO synthase (NOS) inhibitor L-NAME (10 - 100 mg kg(-1) i.p.) or with the selective iNOS inhibitors aminoguanidine (AG; 10 - 100 mg kg(-1) i.p.) or 1400W (0.5 - 1 mg kg(-1) s.c.) inhibited the AI induced by injection of zymosan 30 min later. Local (intra articular) treatment with the NOS inhibitors (L-NAME or AG, 0.1 - 1 micromol; 1400W, 0.01 (micromol) 30 min before zymosan also inhibited the AI. Systemic or local treatment with the NOS inhibitors (L-NAME; AG, 100 mg kg(-1) i.p. or 0.1 micromol joint(-1); 1400W, 1 mg kg(-1) s.c. or 0.01 micromol joint(-1)), 2 h after zymosan did not affect the subsequent AI. Local treatment with the NO donors SNP or SIN-1, 2 h after zymosan did inhibit AI. L-NAME and AG, given i.p. inhibited nitrite but not prostaglandin E(2) (PGE(2)) levels in the joints. L-NAME (100 mg kg(-1)) but not AG (100 mg kg(-1)) increased mean arterial blood pressure. Neither L-NAME, AG nor the NO donor SIN-1 altered articular oedema induced by zymosan. In conclusion, inhibitors of iNOS decrease pain in zymosan arthritis only when given before the zymosan. This was not due to inhibition of articular PGE(2) release or oedema. NO donors also promoted antinociception in zymosan arthritis without affecting oedema.

Topics: Amidines; Animals; Arthritis, Experimental; Benzylamines; Cartilage, Articular; Dinoprost; Edema; Enzyme Inhibitors; Guanidines; Injections, Intra-Articular; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Pain; Pain Measurement; Rats; Rats, Wistar; Zymosan

We used mice deficient in expression of inducible NO synthase (iNOS -/-) to directly examine the role of iNOS in impaired vasoconstrictor responses following tumor necrosis factor-alpha (TNF-alpha). In iNOS +/+ mice, contraction of carotid arteries in response to prostaglandin F(2alpha) (PGF(2alpha)) was impaired following TNF-alpha (100 microg/kg ip)(n = 10, P < 0.01). In contrast to responses in wild-type mice, contraction to low concentrations of PGF(2alpha) were normal, but maximum contraction to PGF(2alpha) was impaired in arteries from iNOS -/- mice treated with TNF-alpha [0.35 +/-.0.02 g (n = 8) following vehicle and 0.25 +/- 0.02 g (n = 7) following TNF-alpha (P < 0.05)]. Aminoguanidine, a relatively selective inhibitor of iNOS, partially restored contraction to PGF(2alpha) in vessels from iNOS +/+ mice but had no effect in iNOS -/- mice injected with TNF-alpha, suggesting that a mechanism(s) other than iNOS contributes to impaired responses. In contrast to contractile responses, relaxation of the carotid artery in response to acetylcholine and nitroprusside was not altered following TNF-alpha in iNOS +/+ or iNOS -/-mice. Responses of carotid arteries from iNOS -/- mice and effects of aminoguanidine suggest that both iNOS-dependent and iNOS-independent mechanisms contribute to impaired contractile responses following TNF-alpha.

Topics: Acetylcholine; Animals; Carotid Arteries; Dinoprost; Enzyme Inhibitors; Guanidines; Mice; Mice, Inbred C57BL; Muscle Contraction; Muscle Relaxation; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Potassium Chloride; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Necrosis Factor-alpha

We have previously shown that aging is associated with increased lipid peroxidation, reductions in renal function, and increased glomerular sclerosis. The mechanism(s) responsible for these age-related changes are not clear. The purpose of the present studies was to determine if there was an increase in inducible nitric oxide synthase (iNOS) with aging, and if so, whether inhibition of iNOS would prevent aging injury by preventing free radical-mediated lipid peroxidation. iNOS protein expression in the kidney increased by approximately 90% by 24 months. Inhibition of iNOS by aminoguanidine (0.1% in drinking water) for 9 months, beginning at 13 months of age, reduced blood pressure, improved glomerular filtration rate by 70%, and renal plasma flow by 40%, whereas glomerular sclerosis was considerably reduced. Renal F2-isoprostanes and malondialdehyde levels, markers of oxidative stress and lipid peroxidation, were not reduced by aminoguanidine. Aminoguanidine also did not attenuate immunostaining for advanced glycosylation end products (AGE) in the kidneys. These findings suggest that aminoguanidine attenuates aging renal dysfunction by inhibiting a pathophysiologic function of iNOS that is independent of free radical-mediated lipid peroxidation or significant effects on AGE deposition.

Topics: Aging; Animals; Biomarkers; Blotting, Western; Dinoprost; Disease Models, Animal; Enzyme Inhibitors; F2-Isoprostanes; Follow-Up Studies; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Glycation End Products, Advanced; Guanidines; Kidney; Lipid Peroxidation; Male; Malondialdehyde; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Oxidative Stress; Rats; Rats, Sprague-Dawley; Renal Plasma Flow

The inducible isoform of nitric oxide synthase (iNOS) is expressed after systemic administration of lipopolysaccharide (LPS). The importance of expression of iNOS in blood vessels is poorly defined. Because nitric oxide from iNOS may alter vasomotor function, we examined effects of LPS on vasomotor function in carotid arteries from iNOS-deficient mice. We studied contraction of the carotid artery from wild-type and iNOS-deficient mice in vitro 12 h after injection of LPS (20 mg/kg ip). Contractile responses to PGF2alpha (3-30 microM) and thromboxane A2 analog (U-46619; 3-100 nM) were evaluated using vascular rings from mice treated with vehicle or LPS. Maximum force of contraction generated by rings in response to PGF2alpha was 0.39 +/- 0.02 and 0.25 +/- 0.01 (SE) g (n = 14) in vehicle and LPS-treated wild-type mice, respectively (P < 0.001 vs. vehicle). Thus LPS reduced constrictor responses in wild-type mice. Thiocitrulline and aminoguanidine (inhibitors of iNOS) improved contractile responses from LPS-treated wild-type vessels. Indomethacin also improved constrictor responses in arteries from wild-type mice injected with LPS. In contrast, contraction of the carotid arteries in response to PGF2alpha and U-46619 was not impaired in LPS-treated iNOS-deficient mice, and contraction was not altered by inhibitors of iNOS. Expression of iNOS mRNA was confirmed using RT-PCR in carotid arteries from wild-type mice after injection of LPS but not vehicle. PCR products for iNOS were not observed in iNOS-deficient mice. These findings provide the first direct evidence that iNOS mediates impairment of vascular contraction after treatment with LPS.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Carotid Arteries; Citrulline; Dinoprost; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; Guanidines; Heterozygote; In Vitro Techniques; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle Contraction; Muscle, Smooth, Vascular; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; RNA, Messenger; Thiourea; Transcription, Genetic; Vasoconstriction

In this paper, we evaluated the hypothesis that prostaglandin F2 alpha (PGF2 alpha) regulates NOS activity and we also investigated, by means of nitric oxide inhibitors (N-monomethyl-L-arginine monoacetate, L-NMMA) the role of endogenous NO on PGF2 alpha-induced contractions in rat oviduct. NOS activity was determined by measuring the conversion of 14[C]-L-arginine to 14[C]-L-citrulline on oviductal homogenates from estrogenized rats (1 microgram/rat). The presence of PGF2 alpha (10(-8) M) in the incubation medium produced an increase in NOS activity (p < or = 0.05). The effect of the prostanoid was blocked completely by the presence of two NOS inhibitors: N-nitro-L-arginine methyl ester (L-NAME, 0.6 mM) and aminoguanidine (Ag, 0.5 mM). These results suggested that PGF2 alpha could be modulating the Ca(2+)-independent NOS activity. We determined NOS activity using 1 mM EGTA, a chelator of Ca2+, in a free Ca2+ medium. These results indicated that PGF2 alpha produces an increase in Ca(2+)-independent NOS activity (p < or = 0.05). PGF2 alpha induces contraction of the oviductal smooth muscle in a concentration dependent manner. L-NMMA enhanced PGF2 alpha induced contraction of the oviduct, providing indirect evidence that there is a basal release of NO in the oviduct, which may reduce and/or modulate the contractile effects of PGF2 alpha.

Topics: Animals; Arginine; Calcium; Chelating Agents; Citrulline; Dinoprost; Egtazic Acid; Enzyme Inhibitors; Fallopian Tubes; Female; Guanidines; Muscle Contraction; Muscle, Smooth; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Rats; Rats, Wistar

Evidence supports the involvement of nitric oxide (NO) in ovarian physiology. The present study was undertaken to investigate the role of the NO/NO synthase (NOS) systems in ovulation, oocyte maturation, ovarian steroidogenesis, and PG production using in vitro perfused rabbit ovaries. The addition of the NOS inhibitors, aminoguanidine hemisulfate salt (AG) and N-omega-nitro-L-arginine methyl ester (L-NAME), to the perfusate inhibited the ovulation induced by hCG in a dose-dependent manner, whereas D-NAME had no significant effect. Neither AG nor L-NAME affected the hCG-induced meiotic maturation of the ovulated ova. The exogenous administration of the NO generator, sodium nitroprusside (NP), induced follicle rupture in the absence of gonadotropin, but did not induce oocyte maturation. Inhibition of endogenous NOS by AG and L-NAME resulted in a significant elevation in the production of estradiol (E2), but not of progesterone, stimulated by hCG. The concomitant administration of NP significantly reduced the AG-stimulated production of E2 by ovaries perfused in the presence of hCG, which suggests that NO down-regulates ovarian E2 synthesis. Ovarian production of PGE2 and PGF2alpha in response to hCG was significantly blocked by L-NAME, and exogenous administration of NP stimulated the production of PGs in the absence of gonadotropin. Significant correlations were observed between the ovulatory efficiencies and the production of PGs by rabbit ovaries perfused with or without L-NAME. In conclusion, the ovarian NO/NOS system is involved in follicle rupture during the ovulatory process. NO may induce follicle rupture in rabbit ovaries at least in part by the stimulation of PG production.

Topics: Animals; Chorionic Gonadotropin; Dinoprost; Dinoprostone; Enzyme Inhibitors; Estradiol; Female; Guanidines; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Nitroprusside; Ovarian Follicle; Ovary; Ovulation; Progesterone; Prostaglandins; Rabbits; Steroids

Pulmonary hypertension is a feature of clinical and experimental acute lung injury. Nitric oxide (NO) synthesis is increased in hyporesponsive systemic and pulmonary conductance arteries after endotoxin (LPS) injection in the rat. We examined the effects of NO synthase (NOS) induction by LPS on vascular reactivity of the isolated perfused rat lung (IPL) using the selective inducible (iNOS) inhibitor aminoguanidine (AG). Baseline pulmonary artery pressures (Ppa) were higher in the LPS compared with the sham-treated rats and were further increased only in the LPS-treated group by AG. Increased NOS activity in whole lung and the vasopressor effect of AG suggested that iNOS was active in pulmonary resistance vessels after LPS treatment. Vasoconstriction to hypoxia, angiotensin II (AII), and prostaglandin F2 alpha (PGF2 alpha) was enhanced or unchanged in LPS-treated rats despite NOS induction. Hence, iNOS activity counterbalances increased pulmonary vascular contractility in this model.

Topics: Angiotensin II; Animals; Dinoprost; Dose-Response Relationship, Drug; Enzyme Induction; Enzyme Inhibitors; Guanidines; Hypoxia; In Vitro Techniques; Lipopolysaccharides; Male; Nitric Oxide Synthase; Pulmonary Artery; Rats; Rats, Wistar; Salmonella enteritidis; Vasoconstriction; Vasoconstrictor Agents

In previous reports we found that nitric oxide is involved in corpus luteum regression in the rat by increasing prostaglandin F2 alpha synthesis during the luteolytic phase. In the present study we were interested in determining whether nitric oxide synthase activity is modulated with the corpus luteum development. For this purpose ovarian tissues obtained from pseudopregnant rats at different stages of pseudopregnancy, early, middle, and late, were used. Working with different doses of two competitive nitric oxide synthase inhibitors, NG-monomethyl-L-arginine (L-NMMA) and aminoguanidine (AG), we investigated the possible role of endogenous nitric oxide in the regulation of prostaglandin F2 alpha production by rat ovaries in the three different phases mentioned. We found that nitric oxide synthase activity diminishes with the corpus luteum development and that the calcium-independent activity was the predominant form of this enzyme in all stages studied. Endogenous nitric oxide increased prostaglandin F2 alpha synthesis only during the late phase of the corpus luteum. In the study of the possible role of nitric oxide regulating ovarian steroidogenesis, we found that L-NMMA increased progesterone production and diminished prostaglandin F2 alpha synthesis in ovarian tissue from pseudopregnant rats in the late phase. These results suggest that nitric oxide could participate in the corpus luteum demise in the rat by modulating part of prostaglandin F2 alpha and progesterone production.

Topics: Analysis of Variance; Animals; Dinoprost; Enzyme Inhibitors; Female; Guanidines; Luteolysis; Nitric Oxide; Nitric Oxide Synthase; omega-N-Methylarginine; Ovary; Progesterone; Pseudopregnancy; Rats; Rats, Wistar