Endothelin-receptor blockade does not alter closure of the ductus arteriosus

1998 ◽  
Vol 275 (5) ◽  
pp. H1620-H1626 ◽  
Author(s):  
Jeffrey R. Fineman ◽  
Yasushi Takahashi ◽  
Christine Roman ◽  
Ronald I. Clyman
Keyword(s):  
Soluble Guanylate Cyclase ◽  
Ductus Arteriosus ◽  
Late Gestation ◽  
Receptor Blockade ◽  
Active Tension ◽  
In Vitro Effects ◽  
Ly 83583

Endothelin-1 (ET-1) is synthesized within the wall of the ductus arteriosus (DA) and is a potent constrictor of the DA in vitro. However, the role of endogenous ET-1 in closure of the DA at birth remains unclear. Therefore, we studied the effects of a selective ETA-receptor antagonist (PD-156707), or its vehicle, on DA closure in 13 late-gestation fetal lambs during the first 5 h after birth. We also studied the effects of ETA-receptor blockade on DA constriction induced by oxygen, indomethacin (a cyclooxygenase inhibitor), and LY-83583 (a soluble guanylate cyclase inhibitor) in vitro ( n = 9 ductus arteriosus rings). In vehicle-treated lambs in vivo, the DA constricted during the 5-h study period after birth: DA resistance increased (from 0.007 ± 0.01 to 3.406 ± 4.15 mmHg ⋅ ml−1 ⋅ min ⋅ kg−1; P < 0.05); the pressure gradient across the DA increased (from 1.4 ± 2.1 to 25.2 ± 9.4 mmHg; P < 0.05); and DA blood flow decreased (from 193.5 ± 48.0 to 19.3 ± 14.3 ml ⋅ kg−1 ⋅ min−1; P < 0.05). In vitro, the DA was constricted by exposure to 30% oxygen (23 ± 14% net active tension; P < 0.05), indomethacin (5 × 10−6 M, 22 ± 5% net active tension; P < 0.05), LY-83583 (10−5 M, 24 ± 10% net active tension; P < 0.05), and ET-1 (10−7 M, 19 ± 4% net active tension; P < 0.05). Although PD-156707 blocked both the in vivo and in vitro effects of exogenous ET-1, it had no effect on postnatal ductus constriction nor on in vitro ductus contractile responses to oxygen, indomethacin, or LY-83583. This study suggests that endogenous ET-1 does not play an important role in closure of the DA at birth.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects

Anti-inflammatory, Antioxidant, Lung and Liver Protective Activity of Galaxaura oblongata as Antagonistic Efficacy against LPS using Hematological Parameters and Immunohistochemistry as Biomarkers

2021 ◽  
Vol 19 ◽  
Author(s):  
Asmaa Nabil-Adam ◽  
Mohamed A. Shreadah
Keyword(s):  
Protective Effect ◽  
Hematological Parameters ◽  
Control Group ◽  
In Vivo Assays ◽  
Induction Group ◽  
Anti Inflammatory ◽  
In Vitro Effects

Background: This study aimed to investigate the potential bioactivity and the ameliorative role of Galaxaura oblongata (G. oblongata) against LPS-induced toxicity by using hematological parameters. Objective: It is aimed also to examine its protective effect using the immunohistochemistry of liver and lungs as biomarkers in male BALB/C albino mice. Materials and Methods: the current study carried out using different in-vitro and in-vivo assays such as phytochemical, antioxidants, anti-inflammatory for in-vitro where the hematological and immunohistochemistry for lung and liver were investigated in vivo. Results: There are no previous studies were performed to investigate the in vivo and in vitro effects of the G. oblongata extracts as antioxidant and anti-inflammatory due to their rareness compared to other red algae. LPS treated mice revealed a significant decrease in total number of WBCs, RBCs, platelets, and HGB%, MPV, MCV and MCHC compared to the control group. On contrast, the HCT and MCHC were increased in the induction group which was treated with LPS compared to the control group. Furthermore, the immunohistochemistry results of the present study revealed the protective effect of G. oblongata compared to the induction group. G. oblongata can be used as protective marine natural products against the toxicity induced by LPS. Conclusion: It exhibited a significant ameliorative role against the alterations in the hematological parameters and immunohistochemistry of liver and lungs, and helps to reduce as well as coordinate the acute inflammations caused by TNF.

scholarly journals Angiotensin II infusion in vivo does not modulate cortisol secretion in the late-gestation ovine fetus

1998 ◽  
Vol 275 (2) ◽  
pp. R357-R362 ◽  
Author(s):  
Kirsten R. Poore ◽  
I. Ross Young ◽  
Benedict J. Canny ◽  
Geoffrey D. Thorburn
Keyword(s):  
Angiotensin Ii ◽  
Adrenal Gland ◽  
Late Gestation ◽  
Treatment Groups ◽  
Arterial Blood ◽  
Basal Cortisol ◽  
Ovine Fetus

Maturation of the fetal adrenal gland is critical for the onset of ovine parturition. It has long been proposed that the fetal adrenal gland may be under inhibitory influences during late gestation. In vitro evidence has suggested that angiotensin II may be such an inhibitory factor and may help to prevent a premature increase in cortisol concentrations. The aim of this study was to test the effect of angiotensin II infusion in vivo on basal cortisol concentrations and fetal adrenal responsiveness to an ACTH-(1—24) challenge. Fetuses received a continuous infusion of either angiotensin II (100 ng ⋅ min−1 ⋅ kg−1; n = 7) or saline (2 ml/h; n = 4), which commenced at 140 days of gestation (GA) and continued for a total of 50 h. Adrenal responsiveness to the administration of ACTH-(1—24) (5 μg/kg) was determined during angiotensin II or saline infusions at both 2 and 48 h after infusion onset. Angiotensin II had no significant effect on adrenal responsiveness after acute (2 h) or chronic (48 h) infusion. There was no effect of saline or angiotensin II infusion on basal immunoreactive ACTH or cortisol concentrations after 2 h, but there was a significant increase in basal cortisol concentrations in both treatment groups by 48 h, probably reflecting the normal rise in cortisol concentrations at this GA. Mean arterial blood pressure was significantly increased in angiotensin II-infused fetuses only. This study has therefore found no evidence to suggest that angiotensin II infusion in vivo modulates fetal basal cortisol concentrations or adrenal responsiveness in the last week of gestation, in contrast with previous in vitro studies. These results throw into question the proposed role of angiotensin II as a negative modulator of adrenal function in the ovine fetus.

The Biologic Role of Interleukin-8: Functional Analysis and Expression of CXCR1 and CXCR2 on Human Eosinophils

Blood ◽  
1999 ◽  
Vol 93 (2) ◽  
pp. 694-702
Author(s):  
Holger Petering ◽  
Otto Götze ◽  
Daniela Kimmig ◽  
Regina Smolarski ◽  
Alexander Kapp ◽  
...  
Keyword(s):  
Allergic Inflammation ◽  
Allergic Diseases ◽  
Interleukin 8 ◽  
Cytokine Activation ◽  
Cc Chemokines ◽  
Eosinophil Granulocytes ◽  
In Vitro Effects

Chemokines play an important role in attracting granulocytes into sites of inflammation. Two chemokine subfamilies differ in their biologic activity for different granulocyte subsets. Whereas CXC chemokines such as interleukin-8 (IL-8) activate predominantly neutrophils, CC chemokines such as RANTES and eotaxin activate predominantly eosinophils. However, controversial results have been published in the past regarding the biologic role of IL-8 in eosinophil activation, particularly in allergic diseases. In this study, we investigated the functional evidence and expression of both IL-8 receptors, CXCR1 and CXCR2, on highly purified human eosinophils. In the first set of experiments, a chemotaxis assay was performed showing that IL-8 did not induce chemotaxis of eosinophils. In addition, and in contrast to neutrophils and lymphocytes, IL-8 did not induce a rapid and transient release of cytosolic free Ca2+([Ca2+]i) in eosinophils, even after preincubation with TH1- and TH2-like cytokines. To investigate whether neutrophil contamination might be responsible for the reported IL-8 effects on eosinophils, neutrophils were added to highly purified eosinophils from the same donor in different concentrations. Interestingly, as little as 5% of neutrophil contamination was sufficient to induce an increase of [Ca2+]iafter stimulation with IL-8. Flow cytometry experiments with monoclonal antibodies against both IL-8 receptors demonstrated no expression of CXCR1 and CXCR2 on eosinophils before or after cytokine activation. Reverse transcriptase-polymerase chain reaction experiments showed that eosinophils, in contrast to neutrophils and lymphocytes, did not express mRNA for CXCR1 and CXCR2. In summary, this study clearly demonstrates that CXCR1 and CXCR2 are not expressed on human eosinophils, even after priming with different bioactive cytokines. Because the CXC chemokine IL-8 did not induce in vitro effects on human eosinophils, IL-8 may also not contribute in vivo to the influx of eosinophil granulocytes into sites of allergic inflammation. Our results suggest that CC chemokines such as eotaxin, eotaxin-2, and MCP-4 are predominant for the activation of eosinophils.

scholarly journals Cinaciguat, a soluble guanylate cyclase activator, augments cGMP after oxidative stress and causes pulmonary vasodilation in neonatal pulmonary hypertension

2011 ◽  
Vol 301 (5) ◽  
pp. L755-L764 ◽  
Author(s):  
Marc Chester ◽  
Gregory Seedorf ◽  
Pierre Tourneux ◽  
Jason Gien ◽  
Nancy Tseng ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Ductus Arteriosus ◽  
No Donor ◽  
Fetal Sheep ◽  
Cgmp Production ◽  
Pulmonary Vasodilation

Although inhaled NO (iNO) therapy is often effective in treating infants with persistent pulmonary hypertension of the newborn (PPHN), up to 40% of patients fail to respond, which may be partly due to abnormal expression and function of soluble guanylate cyclase (sGC). To determine whether altered sGC expression or activity due to oxidized sGC contributes to high pulmonary vascular resistance (PVR) and poor NO responsiveness, we studied the effects of cinaciguat (BAY 58-2667), an sGC activator, on pulmonary artery smooth muscle cells (PASMC) from normal fetal sheep and sheep exposed to chronic intrauterine pulmonary hypertension (i.e., PPHN). We found increased sGC α1- and β1-subunit protein expression but lower basal cGMP levels in PPHN PASMC compared with normal PASMC. To determine the effects of cinaciguat and NO after sGC oxidation in vitro, we measured cGMP production by normal and PPHN PASMC treated with cinaciguat and the NO donor, sodium nitroprusside (SNP), before and after exposure to 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, an sGC oxidizer), hyperoxia (fraction of inspired oxygen 0.50), or hydrogen peroxide (H2O2). After treatment with ODQ, SNP-induced cGMP generation was markedly reduced but the effects of cinaciguat were increased by 14- and 64-fold in PPHN fetal PASMC, respectively ( P < 0.01 vs. controls). Hyperoxia or H2O2enhanced cGMP production by cinaciguat but not SNP in PASMC. To determine the hemodynamic effects of cinaciguat in vivo, we compared serial responses to cinaciguat and ACh in fetal lambs after ductus arteriosus ligation. In contrast with the impaired vasodilator response to ACh, cinaciguat-induced pulmonary vasodilation was significantly increased. After birth, cinaciguat caused a significantly greater fall in PVR than either 100% oxygen, iNO, or ACh. We conclude that cinaciguat causes more potent pulmonary vasodilation than iNO in experimental PPHN. We speculate that increased NO-insensitive sGC may contribute to the pathogenesis of PPHN, and cinaciguat may provide a novel treatment of severe pulmonary hypertension.

Anti-obesity role of adzuki bean extract containing polyphenols: in vivo and in vitro effects

2012 ◽  
Vol 92 (13) ◽  
pp. 2644-2651 ◽  
Author(s):  
Tomoko Kitano-Okada ◽  
Ayano Ito ◽  
Ai Koide ◽  
Yumi Nakamura ◽  
Kyu-Ho Han ◽  
...  
Keyword(s):  
Adzuki Bean ◽  
In Vitro Effects

Role of wall tension in hypoxic responses of isolated rat pulmonary arteries

1998 ◽  
Vol 275 (6) ◽  
pp. L1069-L1077 ◽  
Author(s):  
Masami Ozaki ◽  
Carol Marshall ◽  
Yoshikiyo Amaki ◽  
Bryan E. Marshall
Keyword(s):  
Pulmonary Arteries ◽  
Mechanical Stretch ◽  
Effective Concentration ◽  
Active Tension ◽  
Wall Tension ◽  
Subsequent Response ◽  
Isolated Rat

The changes in force developed during 40-min exposures to hypoxia (37 ± 1 mmHg) were recorded in large (0.84 ± 0.02-mm-diameter) and small (0.39 ± 0.01-mm-diameter) intrapulmonary arteries during combinations of mechanical wall stretch tensions (passive + active myogenic components), equivalent to transmural vascular pressures of 5, 15, 30, 50, and 100 mmHg, and active (vasoconstriction) tensions, stimulated by PGF2α in doses of 0, 25, 50, and 75% effective concentrations. Constriction was observed in all arteries during the first minute; however, at any active tension, the pattern of the subsequent response was a function of the stretch tension. At 5, 15, and 30 mmHg, the constriction decreased slightly at 5 min and then increased again to remain constrictor throughout. At 50 and 100 mmHg, the initial constriction was followed by persistent dilation. Hypoxic constrictor responses, most resembling those observed in lungs in vivo and in vitro, were observed when the mechanical stretch wall tension was equivalent to 15 or 30 mmHg and the dose of PGF2α was 25 or 50% effective concentration. These observations reconcile many apparently contradictory results reported previously.

Interleukin 1 and endotoxin activate soluble guanylate cyclase in vascular smooth muscle

1990 ◽  
Vol 259 (1) ◽  
pp. R38-R44 ◽  
Author(s):  
D. Beasley
Keyword(s):  
Nitric Oxide ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Interleukin 1 ◽  
Physiological Salt Solution ◽  
Initial Exposure ◽  
Vasodilatory Action ◽  
Ly 83583

Our recent studies indicate that interleukin 1 (IL-1) and bacterial lipopolysaccharide inhibit agonist-induced contractions in rat aortic rings by an endothelium-independent mechanism. The present study investigated the role of guanosine 3',5'-cyclic monophosphate (cGMP) in the vasodilatory action of IL-1 and endotoxin. Rat aortic rings were denuded of endothelium and incubated for 3 h in physiological salt solution containing no additions, IL-1 (20 ng/ml), or endotoxin (10 micrograms/ml). Contractions induced by phenylephrine (3 x 10(-7) M) were decreased by 40 and 85% in endotoxin- and IL-1-treated rings, respectively. IL-1 increased cGMP content 2.5-fold in the absence of and 5.5-fold in the presence of 3-isobutyl-1-methylxanthine (IBMX). Endotoxin also increased cGMP content in the absence and presence of IBMX (5.5- and 25-fold, respectively). Both IL-1- and endotoxin-induced increases in cGMP occurred 3-4 h after initial exposure. The guanylate cyclase inhibitors, LY 83583 and methylene blue, each abolished IL-1- and endotoxin-induced inhibition of contraction and IL-1-induced production of cGMP. Furthermore, hemoglobin, which binds nitric oxide, completely blocked IL-1-induced increases in cGMP. We conclude that IL-1 and endotoxin inhibit vascular contraction in vitro by increasing aortic cGMP content. Studies with inhibitors suggest IL-1 and endotoxin may induce endothelium-independent production of nitric oxide or another free radical that activates soluble guanylate cyclase.

scholarly journals Characterization of PGE2 receptors in fetal and newborn lamb ductus arteriosus

2001 ◽  
Vol 280 (5) ◽  
pp. H2342-H2349 ◽  
Author(s):  
Asmàa Bouayad ◽  
Hiroki Kajino ◽  
Nahid Waleh ◽  
Jean-Claude Fouron ◽  
Gregor Andelfinger ◽  
...  
Keyword(s):  
Radioligand Binding ◽  
Ductus Arteriosus ◽  
Late Gestation ◽  
Receptor Subtype ◽  
Total Density ◽  
Newborn Lamb ◽  
Camp Formation ◽  
Stimulation Of

Although the role of PGE2 in maintaining ductus arteriosus (DA) patency is well established, the specific PGE2 receptor subtype(s) (EP) involved have not been clearly identified. We used late gestation fetal and neonatal lambs to study developmental regulation of EP receptors. In the fetal DA, radioligand binding and RT-PCR assays virtually failed to detect EP1 but detected EP2, EP3D, and EP4 receptors in equivalent proportions. In the newborn lamb, DA total density was one-third of that found in the fetus and only EP2 was detected. Stimulation of EP2 and EP4 increased cAMP formation and was associated with DA relaxation. Though stimulation of EP3 inhibited cAMP formation, it surprisingly relaxed the fetal DA both in vitro and in vivo. This EP3-induced relaxation was specifically diminished by the ATP-sensitive K+ (KATP) channel blocker glibenclamide. In conclusion, PGE2 dilates the late gestation fetal DA through pathways that involve either cAMP (EP2 and EP4) or KATP channels (EP3). The loss of EP3 and EP4receptors in the newborn DA is consistent with its decreased responsiveness to PGE2.

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