Patterns of Gene Expression in the Bovine Corpus Luteum Following Repeated Intrauterine Infusions of Low Doses of Prostaglandin F2alpha

Natural luteolysis involves multiple pulses of prostaglandin F2alpha (PGF) released by the nonpregnant uterus. This study investigated expression of 18 genes from five distinct pathways, following multiple low-dose pulses of PGF. Cows on Day 9 of the estrous cycle received four intrauterine infusions of 0.25 ml of phosphate-buffered saline (PBS) or PGF (0.5 mg of PGF in 0.25 ml of PBS) at 6-h intervals. A luteal biopsy sample was collected 30 min after each PBS or PGF infusion. There were four treatment groups: Control (n = 5; 4 PBS infusions), 4XPGF (4 PGF infusions; n = 5), 2XPGF-non-regressed (2 PGF infusions; n = 5; PGF-PBS-PGF-PBS; no regression after treatments), and 2XPGF-regressed (PGF-PBS-PGF-PBS; regression after treatments; n = 5). As expected, the first PGF pulse increased mRNA for the immediate early genes JUN, FOS, NR4A1, and EGR1 but unexpectedly also increased mRNA for steroidogenic (STAR) and angiogenic (VEGFA) pathways. The second PGF pulse induced immediate early genes and genes related to immune system activation (IL1B, FAS, FASLG, IL8). However, mRNA for VEGFA and STAR were decreased by the second PGF infusion. After the third and fourth PGF pulses, a distinctly luteolytic pattern of gene expression was evident, with inhibition of steroidogenic and angiogenic pathways, whereas, there was induction of pathways for immune system activation and production of PGF. The pattern of PGF-induced gene expression was similar in corpus luteum not destined for luteolysis (2X-non-regressed) after the first PGF pulse but was very distinct after the second PGF pulse. Thus, although the initial PGF pulse induced mRNA for many pathways, the second and later pulses of PGF appear to have set the distinct pattern of gene expression that result in luteolysis.

Mechanism of calcium hydroxide-induced neutrophil migration into air-pouch cavity

The aim of this study was to investigate cellular migration induced by calcium hydroxide to air-pouch cavities in mice. The migration was more specific to neutrophil and was dose and time dependent (peaking 96 h after stimulation). This migration was inhibited by pretreatment with thalidomide, indomethacin, MK886, meloxicam, dexamethasone, MK886 associated with indomethacin, and MK886 associated with indomethacin and dexamethasone. The air-pouch exudate from animals stimulated with calcium hydroxide showed an increase of leukotriene-B4 (LTB4), interleukin-1 beta, tumor necrosis factor alpha (TNF-alpha), cytokine-induced neutrophil chemoattractant (KC), and macrophage inflammatory protein 2 (MIP-2) release. Pretreatment with 3% thioglycollate increased the macrophage population in the air pouch but did not change neutrophil migration. Depleting the resident mast cells through chronic pretreatment with compound 48/80 did not alter neutrophil migration in response to calcium hydroxide. It was possible to conclude that calcium hydroxide-induced neutrophil migration to the air-pouch cavity in mice is mediated by LTB4, TNF-alpha, KC, MIP-2, and prostaglandins, but it was not dependent on macrophages or mast cells.

Effects of Ethanol on Synthesis of Prostaglandin F2 alpha in Bovine Females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antiulcerogenic activity of four extracts obtained from the bark wood of Quassia amara L. (Simaroubaceae)

Quassia amara L., a neotropical forest shrub of the Simaroubaceae family, is widely used in Caribbean folk medicine and in some northern states of Brazil for the treatment of gastric ulcers. This plant is a source of numerous compounds including both beta-carbonile and cantin-6 alkaloids as well as, primarily, the bitter compounds known as quassinoids. We analyzed the possible antiulcerogenic activities of four extracts of different polarities: 70% ethanol (70% EtOH), 100% EtOH, 100% dichloromethane (DCM), and 100% hexane (HEX) obtained from Quassia amara bark. All extracts, administered at doses of 5000 mg/kg orally and 1000 mg/kg intraperitoneally, caused neither toxicity or death. In the indomethacin[bethanechol-induced gastric ulcer, 70% EtOH, 100% EtOH, DCM and HEX extracts, 100 mg/kg, p.o., inhibited the gastric ulcer (22.5, 23.4, 50.5, 46.8%, respectively). 70% EtOH, 100% EtOH, DCM, and HEX extracts reduced the gastric injury induced by the hypothermic restraint-stress test in mice (70.7, 80, 60, 82.7%, respectively). In the pylorus ligature of the mouse stomach, following pre-treatment with a single intraduodenal administration of 100 mg/kg of each extract, only 70% EtOH did not change the biochemical parameters of gastric juice. 100% EtOH, DCM and HEX extracts presented decreased gastric juice content, increased pH values and decreased acid output. We also determined the antiulcerogenic activity on HCl-EtOH-induced gastric ulcers in mice at four doses (25, 50, 75, 100 mg/kg, p.o.), then evaluated the possible dose-dependent relation and calculated the ED50 values. Except for 70% EtOH at a dose of 25 mg/kg, the other extracts showed significantly activity (p<0.05). The free mucous amount in the gastric stomach content was also evaluated. All extracts showed significant increases (p<0.05) of free mucous. This effect was abolished when the animals were pre-treated with indomethacin. Prostaglandin synthesis was evaluated by the administration of HEX extracts by the oral route (100 mg/kg). Prostaglandin synthesis was significantly, increased by 52.3% (p<0.05), and this effect was abolished with prior administration of indomethacin. We concluded that Quassia amara is a probable source for a new drug to treat gastric ulcers, and the mechanism of its activity relates to cytoprotective factors, such as mucous and prostaglandins, but there is still the possibility that antisecretory activity is involved in its antiulcerogenic effect.

Mechanisms of action underlying the gastric antiulcer activity of the Rhizophora mangle L.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Eficácia da dose reduzida de gonadorelina e diferentes prostaglandinas no protocolo ovsynch em vacas holandesas

Avaliou-se a eficácia da dose de 0,10 ou de 0,25mg de gonadorelina nas taxas de ovulação e de sincronização no protocolo Ovsynch e de 150mcg de D-cloprostenol ou 0,530mg de cloprostenol sódico na regressão do corpo lúteo (CL) de sete dias e de todos os CL. Foram utilizadas 136 vacas lactantes da raça Holandesa, com média de produção de leite de 23,75,8kg/dia, com 138,4±72,0 dias em lactação. As vacas foram distribuídas aleatoriamente em quatro grupos, de acordo com a dose de gonadorelina e o tipo da prostaglandina. As taxas de ovulação e de sincronização foram de 52,9% e 80,9% para 0,10mg de gonadorelina e de 57,4% e 80,9% para 0,25mg de gonadorelina, respectivamente. A taxa de regressão do CL de sete dias foi de 97,1% para o D-cloprostenol e de 97,5% para o cloprostenol sódico. A taxa de prenhez não foi influenciada pelos tratamentos, mas foi influenciada pela taxa de ovulação à primeira aplicação de gonadorelina, 16,0% vs. 6,6% para as vacas que ovularam e não ovularam, respectivamente. Conclui-se que 0,10mg de gonadorelina foi eficiente e ambas prostaglandinas podem ser usadas em protocolos de sincronização da ovulação.

Alterações fetais induzidas pelo uso de antiinflamatórios durante a gestação

Em geral, todos os efeitos dos antiinflamatórios estão relacionados com a inibição da ciclo-oxigenase (COX) do ácido araquidônico e, portanto, inibição da produção de prostaglandinas e tromboxanos. Existem dois tipos de COX, quais sejam COX-1 e COX-2. A COX-1 é uma enzima constitucional expressa em muitos tecidos, incluindo plaquetas sangüíneas, e está envolvida na homeostase tecidual. Por outro lado, a COX-2 é induzida em células inflamatórias quando elas são ativadas, sendo considerada a enzima que produz os mediadores da inflamação da classe dos prostanóides. A ação dos antiinflamatórios está relacionada à inibição da COX-2 e é provável que seus efeitos indesejados se devam principalmente à inibição da COX-1. Tratamentos maternos com antiinflamatórios não esteroidais (AINEs) têm sido associados, com freqüência, à vasoconstrição do ducto arterioso fetal, hipertensão arterial pulmonar e inibição da agregação plaquetária. Alterações na hemostasia são alguns dos efeitos colaterais produzidos pelo uso incontrolado dos AINEs, os quais induzem a um desequilíbrio na liberação de prostaglandinas e tromboxanos, que se reflete na adesividade e agregação plaquetária. As alterações hemostáticas observadas em neonatos, decorrentes do uso de salicilatos pela mãe, ocorrem devido à inibição da agregação plaquetária e à diminuição da atividade do fator XII relacionado à coagulação sangüínea. Estudos em camundongos revelaram que o uso de corticóides durante a gestação pode levar a anormalidades no desenvolvimento fetal, por alterações na diferenciação celular.

Gastric antiulcer activity of Syngonanthus arthrotrichus SILVEIRA

Syngonanthus arthrotrichus SILVEIRA, popularly known as sempre-vivas mini-saia, is found in mountains of the Espinhaco range in the Brazilian states of Bahia and Minas Gerais. Extracts of this species contain several constituents, including flavonoids which may have antiulcerogenic activity. An ethanolic extract (EEOH), and flavonoid-rich (FRF) and flavonoid-deficient (FDF) fractions obtained from the scapes of S. arthrotrichus were investigated for their ability to prevent ulceration of the gastric mucosa in mice and rats. In the ethanol/HCl-induced ulcer model, lansoprazole (30 mg/kg), EEOH (50, 100, 250 mg/kg) given orally protected the gastric mucosal against injury in mice by 79%, 78%, 73%, and 64% respectively. In the ethanol-induced gastric ulcer model in rats, the lansoprazole (30 mg/kg), FRF and FDF (100 mg/kg) significantly protected the gastric mucosal of rats by 65%, 38% and 25% respectively when compared with the negative control group. In indomethacin/ bethanechol-induced gastric ulcers, cimetidine (100 mg/kg) and the EEOH (100, 250 mg/kg) inhibited gastric ulcer formation by 73%, 55% and 32% respectively. In this exactly model other treatments as cimetidine, FRF and FDF (100 mg/kg) each caused 54%, 36% and 45% inhibition, respectively. In the stress-induced gastric ulcer model, cimetidine (100 mg/kg) and the EEOH (50, 100, 250 mg/kg), inhibited gastric ulcer formation by 63%, 73%, 68% and 69% respectively. In the same model, cimetidine, FRF and FDF (100 mg/kg) significantly protected the gastric mucosal of the mice by 60%, 51% and 47% when compared to the control group. In pylorus-ligated mice, cimetidine (positive control) and FRF significantly decreased gastric acid secretion, increased gastric pH and reduced the acid output when compared to the negative control. FDF had no significant effect on these parameters. The protection provided by FRF probably involved an antisecretory mechanism mediated by flavonoids which were absent in FDF. The amount of adherent mucous in the stomach contents was also evaluated with the treatments carbenoxolone (200 mg/kg), FRF and FDF (100 mg/kg) treatment. Each treatments significantly increased the amount of adherent mucous in the gastric juice (8.67 +/- 1.73, 3.35 +/- 1.59, 2.1 +/- 0.41 mg/g of wet tissue, respectively) compared to the control group, indicating a cytoprotective action on the gastric mucosa. Treatment with FRF plus indomethacin and FDF plus indomethacin reduced the prostaglandin biosyntesis (13.6 +/- 6.5, 27 +/- 5.5 pg/well) by the mucosa, indicating that the cytoprotective action on the gastric mucosa was not related to the level of prostaglandins. Only FDF (38 +/- 17 pg/well) maintained the level of prostaglandins and guaranteed the integrity of the mucosa. The results indicate that the EEOH, FRF and FDF have antisecretory and cytoprotective actions, that may be related to the presence of luteoline in the extract and active fractions.

Effects of diethylpropion treatment and withdrawal on aorta reactivity, endothelial factors and rat behavior

Diethylpropion (DEP) is an amphetamine-like compound used as a coadjutant in the treatment of obesity and which presents toxicological importance as a drug of abuse. This drug causes important behavioral and cardiovascular complications; however, the vascular and behavioral alterations during DEP treatment and withdrawal, have not been determined. We evaluated the effects of DEP treatment and withdrawal on the rat aorta reactivity to noradrenaline, focusing on the endothelium, and the rat behavior during DEP treatment and withdrawal. DEP treatment caused a hyporreactivity to noradrenaline in aorta, reversible after 2 days of withdrawal and abolished by both the endothelium removal and the presence of L-NAME, but not by the presence of indomethacin. Furthermore, DEP treatment increased the general activity of rats. Contrarily, DEP withdrawal caused a decrease in the locomotor activity and an increase in grooming behavior, on the 2nd and 7th days after the interruption of the treatment, respectively. DEP treatment also caused an adaptive vascular response to noradrenaline that seems to be dependent on the increase in the endothelial nitric oxide system activity, but independent of prostaglandins synthesis. The data evidenced chronological differences in the adaptive responses of the vascular and central nervous systems induced by DEP treatment. Finally, a reversion of the adaptive response to DEP was observed in the vascular system during withdrawal, whereas a neuroadaptive process was still present in the central nervous system post-DEP. These findings advance on the understanding of the vascular and behavioral pathophysiological processes involved in the therapeutic and abusive uses of DEP. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Effectiveness and safety of a new vaginal misoprostol product specifically labeled for cervical ripening and labor induction

Objective. The purpose of this study was to evaluate the effectiveness and safety of misoprostol in two different formulations: vaginal tablets of 25 mu g and one-eighth of a 200-mu g oral tablet, also administered intravaginally, for cervical ripening and labor induction of term pregnancies with an indication for that. Methods. A single-blind, randomized, controlled clinical trial was carried out in 120 pregnant women who randomly received one of the two formulations. The main dependent variables were mode of delivery, need for additional oxytocin, time between beginning of induction and delivery, perinatal results, complications, and maternal side effects. Student's t, Mann-Whitney, chi(2), Fisher's Exact, Wilcoxon and Kolmogorov-Smirnoff tests, as well as survival analysis, were used in the data analysis. Results. There were no significant differences between the groups in terms of general characteristics, uterine contractility, and fetal well-being during labor, cesarean section rates, perinatal outcomes, or maternal adverse events. The mean time between the beginning of cervical ripening and delivery was 31.3 h in the vaginal tablet group and 30.1 h in the oral tablet group, a difference that was not statistically significant. Conclusion. The results showed that the 25-mu g vaginal tablets of misoprostol were as effective and safe for cervical ripening and labor induction as the dose-equivalent fraction of 200-mu g oral tablets.

Effect of dipyrone, L-NAME and L-arginine on endotoxin-induced rat paw edema

Paw edema was induced in male Wistar rats (200-250 g) by intraplantar (ipl) administration of 2.5 mu g endotoxin (Etx). Etx, like carrageenin, produced two distinct edema formation phases, an early phase (75 min) followed by a late phase (7 h). We showed that the edema formation in the early phase was antagonized by dipyrone (80 mg/kg, ip) and indomethacin (1 mg/kg, ip) by 52% and 55%, respectively, and that the late phase was resistant to these drugs. These results suggest that in the early phase prostaglandins appear to be involved in the process. However, the activation of the kinin cascade leading to the release of other mediators may be involved in the increase of edema in the late phase. To test this hypothesis, we investigated whether the release of nitric oxide (NO) is involved in the mechanism of endotoxin-induced rat paw edema during the late phase, using N omega-nitro-L-arginine methyl ester (L-NAME) (50 mu g, ipl) as inhibitor of NO synthase and L-arginine (1 mg, ipl) as substrate of NO synthase. The paw edema induced by Etx was inhibited by L-NAME by 56% and increased by L-arginine by 81%. Furthermore, L-arginine given in combination with L-NAME completely reversed the inhibition of Etx-induced edema produced by L-NAME. These results support the hypothesis that in the late phase NO production is associated with the edema evoked by Etx.

HIPERTERMIA EM RATOS INDUZIDA PELA LESAO ELETROLITICA DO MESENCEFALO: PARTICIPACAO DAS PROSTAGLANDINAS

The present studies were conducted to determine the role of prostaglandins in the etiology of a rise of body temperature observed in rats after electrolytic lesion made on the dorsal mesencephalic areas. This hyperthermia was abolished by intraperitoneal administration of indomethacin, an inhibitor of prostaglandins synthesis. These results strengthen the suggestion of a similar mechanism for both neurogenic hyperthermia and the fevers produced by pyrogens. However, until further experiments are carried out, the possibility of lesion in producing hyperthermia by different mechanisms cannot be ruled out.

Efeitos de diferentes doses de tenoxicam sobre a medula espinhal e as meninges. Estudo experimental em caes

Background and Objectives. The analgesic actions of nonsteroidal anti-inflammatory drugs (NSAID) result from the inhibition of the peripheral synthesis of prostaglandins. In spite of the emphasis on the peripheral action, several studies have shown the potential central action of such drugs. In rats, NSAID doses insufficient to block pain when systemically administered were effective when intrathecally injected. This effect could be mediated by interaction with descending serotoninergic ways together with neurotransmission modulation of glycine or N-methyl-D-aspartate receptors. Our goal was to study the effect of different tenoxican doses in the histology of dogs spinal cord and meninges. Methods. Thirty two dogs (7 to 17 kg) were randomly distributed in four groups: G1 - Control with distilled water (DW); G2 - 2 mg tenoxican diluted in DW; G3 - 4 mg tenoxican diluted in DW; G4 - 10 mg tenoxican diluted in DW in a constant volume of 1 ml. Anesthesia was induced with etomidate and fentanyl and dural puncture was performed with a 25G spinal needle in interspace L6-7. Animals were observed for 72 hours and subsequently euthanized by electrocution. Lumbar and sacral spinal cord segments were removed for further histologic examination. Results. All animals were clinically normal during the observation period and there has been no histologic alteration of the nervous system and meninges. Conclusions. In our experimental model intrathecal tenoxican doses up to 10 mg have not triggered nervous tissue or meningeal injuries in dogs.

Immunohistochemical expression of HLA-DR in the conjunctiva of patients under topical prostaglandin analogs treatment

PURPOSE: Subclinical inflammation may be observed in patients using topical antiglaucomatous drugs. The objective of this study was to investigate inflammation in conjunctiva of glaucoma patients using prostaglandin analogs, by the detection of an immunogenetic marker (HLA-DR) and compare the effect of 3 different drugs: latanoprost, bimatoprost, and travoprost in the induction of this inflammation. SUBJECTS AND METHODS: Thirty-three patients with primary open-angle glaucoma were evaluated without and with prostaglandin analogs topical therapy. Imprints of conjunctival cells were obtained, fixed on glass slides, and prepared for immunohistochemical analysis. RESULTS: Before the use of prostaglandin analogs, 4 of the 33 patients evaluated presented expression of HLA-DR in the conjunctiva (mild). After 1 month on prostaglandin analog treatment, all but 1 patient presented HLA-DR staining. HLA-DR expression of these 32 patients was scored as mild (19 patients), medium (11 patients), or intense (2 patients). The differences were statistically significant both when the presence and the increased expression of HLA-DR were considered (P<0.001). When the 3 different groups were analyzed (latanoprost, bimatoprost, and travoprost) no statistically significant difference was found (P=0.27). CONCLUSIONS: The use of prostaglandin analogs eye drops provokes a subclinical inflammatory reaction, observed by HLA-DR expression, even after a short period of treatment, independently of the class of the prostaglandin analogs used. © 2009 Lippincott Williams & Wilkins, Inc.

Neither plasma progesterone concentrations nor exogenous eCG affects rates of ovulation or pregnancy in fixed-time artificial insemination (FTAI) protocols for puberal Nellore heifers

The objective was to evaluate the effects of plasma progesterone (P4) concentrations and exogenous eCG on ovulation and pregnancy rates of pubertal Nellore heifers in fixed-time artificial insemination (FTAI) protocols. In Experiment 1 (Exp. 1), on Day 0 (7 d after ovulation), heifers (n = 15) were given 2 mg of estradiol benzoate (EB) im and randomly allocated to receive: an intravaginal progesterone-releasing device containing 0.558 g of P4 (group 0.5G, n = 4); an intravaginal device containing 1 g of P4 (group 1G, n = 4); 0.558 g of P4 and PGF2α (PGF; 150 μg d-cloprostenol, group 0.5G/PGF, n = 4); or 1 g of P4 and PGF (group 1G/PGF, n = 3). On Day 8, PGF was given to all heifers and intravaginal devices removed; 24 h later (Day 9), all heifers were given 1 mg EB im. In Exp. 2, pubertal Nellore heifers (n = 292) were treated as in Exp. 1, with FTAI on Day 10 (30 to 36 h after EB). In Exp. 3, pubertal heifers (n = 459) received the treatments described for groups 0.5G/PGF and 1G/PGF and were also given 300 IU of eCG im (groups 0.5G/PGF/eCG and 1G/PGF/eCG) at device removal (Day 8). In Exp. 1, plasma P4 concentrations were significantly higher in heifers that received 1.0 vs 0.588 g P4, and were significantly lower in heifers that received PGF on Day 0. In Exp. 2 and 3, there were no significant differences among groups in rates of ovulation (65-77%) or pregnancy (Exp. 2: 26-33%; Exp. 3: 39-43%). In Exp. 3, diameter of the dominant ovarian follicle on Day 9 was larger in heifers given 0.558 g vs 1.0 g P4 (10.3 ± 0.2 vs 9.3 ± 0.2 mm; P < 0.01). In conclusion, lesser amounts of P4 in the intravaginal device or PGF on Day 0 decreased plasma P4 from Days 1 to 8 and increased diameter of the dominant follicle on Day 9. However, neither of these nor 300 IU of eCG on Day 8 significantly increased rates of ovulation or pregnancy. © 2011.