Evaluation of Dose and Route Effects of Platelet Activating Factor-Induced Extravasation in the Guinea Pig

1984 ◽  
Vol 52 (01) ◽  
pp. 034-036 ◽  
Author(s):  
Dean A Handley ◽  
Ronald G Van Valen ◽  
Mary Kay Melden ◽  
Robert N Saunders
Keyword(s):  
Guinea Pig ◽  
Platelet Activating Factor ◽  
The Other ◽  
Plasma Extravasation ◽  
Dependent Manner ◽  
Naturally Occurring ◽  
Protein Rich ◽  
Dose Dependent

SummaryPlatelet-activating factor (PAF) is a naturally occurring lipid that is reported to induce vessel hyperpermeability leading to loss of protein-rich plasma (extravasation). We have quantitated the systemic extravasation effects of synthetic PAF in the guinea pig by monitoring increases in hematocrit. When given intravenously (10-170 ng/kg), PAF produced dose-dependent increases in hematocrit, with maximal hemoconcentration developing in 5-7 min. In leukopenic animals the expected hematocrit increase was reduced by 57%. PAF given intra-arterially produced the dose-dependent changes in hematocrit similar to the intravenous effects of PAF. However, PAF given intraperitoneally (10-2500 μg/kg) was 800-1100-fold less effective than the other routes and hemoconcentration continued for 30-45 min until a maximal hematocrit was observed. These results show that PAF may markedly influence extravasation of plasma in a dose and route-dependent manner.

Effects of Platelet-Activating Factor on Leukocyte Adhesion in the Guinea Pig Aorta

1985 ◽  
Vol 43 ◽  
pp. 684-685
Author(s):  
Mary Kay Melden ◽  
Ronald G. Van Valen ◽  
Robert N. Saunders ◽  
Dean A. Handley
Keyword(s):  
Blood Vessel ◽  
Guinea Pig ◽  
Intravenous Injection ◽  
Leukocyte Adhesion ◽  
Platelet Activating Factor ◽  
Dependent Manner ◽  
Cardiac Effects ◽  
Small Vessels ◽  
Dose Dependent

Platelet-activating factor (PAF) is a potent mediator of immune anaphylaxis. In a dose-dependent manner, PAF can induce such effects as thrombocytopenia, neutropenia, hypotension, bronchoconstriction, hemoconcentration, and negative inotropic cardiac effects. By intradermal or intravenous injection, PAF has been shown to induce blood vessel hyperpermeability resulting in extravasation of plasma, leukocyte adhesion and subsequent diapedesis. However, most studies of endothelial-leukocyte interactions have been limited to small vessels. We have examined the effects of PAF on endothelial structure and leukocyte involvement in the guinea pig aorta.

Effects of interleukin 5-induced pulmonary eosinophilia on airway reactivity in the guinea pig

1996 ◽  
Vol 270 (3) ◽  
pp. L368-L375 ◽  
Author(s):  
C. M. Lilly ◽  
R. W. Chapman ◽  
S. J. Sehring ◽  
P. J. Mauser ◽  
R. W. Egan ◽  
...  
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Airway Hyperresponsiveness ◽  
Histological Grade ◽  
Platelet Activating Factor ◽  
Inflammatory Cells ◽  
Dependent Manner ◽  
Interleukin 5 ◽  
Dose Dependent

Administration of interleukin 5 (IL-5) to guinea pigs by tracheal injection was associated with increased recovery of eosinophils and neutrophils from bronchoalveolar lavage (BAL) fluid. The number of eosinophils recovered from BAL fluid increased in a dose-dependent manner from 9 +/- 2 X 10(3)/ml to a plateau of 143 +/- 29 X 10(3)/ml after the administration of recombinant human IL-5 (rhIL-5). Tracheal administration of recombinant guinea pig IL-5 (gpIL-5) also increased eosinophil recovery but was less potent than rhIL-5. Histological analysis confirmed the presence of inflammatory cells in the lung; there were higher grades of inflammation in airway than in parenchymal tissue after gpIL-5 administration. In addition, the histological grade of airway inflammation was greater 24 and 72 h after gpIL-5 administration than it was 6 days after administration. Airway hyperresponsiveness is reported to occur in guinea pigs exposed to rhIL-5 by intraperitoneal cellular production. It is surprising that airway infiltration with eosinophils induced by the topical application of IL-5 was not associated with hyperresponsiveness to substance P, histamine, or platelet-activating factor in intact animals or to methacholine in tracheally perfused lungs. Furthermore, the microvascular leakage induced by substance P was not altered by rhIL-5 administration. These findings indicate that the presence of eosinophils alone is not sufficient for the expression of airway hyperresponsiveness. Our ability to separate eosinophil recruitment and retention in the tissues from airway hyperresponsiveness indicates that these two processes are distinct and that the presence of eosinophils in lung tissue, by itself, is not sufficient to alter airway contractile responses.

Effect of platelet-activating factor on airway vascular permeability: possible mechanisms

1987 ◽  
Vol 63 (2) ◽  
pp. 479-484 ◽  
Author(s):  
T. W. Evans ◽  
K. F. Chung ◽  
D. F. Rogers ◽  
P. J. Barnes
Keyword(s):  
Vascular Permeability ◽  
Evans Blue ◽  
Platelet Activating Factor ◽  
Blue Dye ◽  
Base Line ◽  
Plasma Extravasation ◽  
Dependent Manner ◽  
Lipoxygenase Inhibitor ◽  
Dose Dependent ◽  
Evans Blue Extravasation

We studied the effects of the potent inflammatory mediator, platelet-activating factor (PAF), on vascular permeability in airways (and other tissues) of guinea pigs by measuring extravasation of circulating Evans blue dye. PAF caused a dose-dependent increase in vascular permeability. At 1 ng/kg iv, PAF caused an increase in Evans blue extravasation of 220% (P less than 0.05) in the trachea, with the greatest effect at a dose of 100 ng/kg (858%; P less than 0.01). Histamine (150 micrograms/kg iv) caused a 320% increase over base line in the trachea and 200% in main bronchi; this effect was equivalent to that induced by 10 ng/kg PAF in the trachea and 1 ng/kg in main bronchi. The duration of effect of PAF was greatest in main bronchi (less than 10 min). Platelet depletion with a cytotoxic antibody, or the cyclooxygenase inhibitor, indomethacin, or the cyclooxygenase-lipoxygenase inhibitor, BW 7556, did not affect the vascular permeability response to PAF. The PAF-receptor antagonist, BN 52063, inhibited Evans blue extravasation in the airways in a dose-dependent manner, with complete inhibition at 5 mg/kg. Thus PAF-induced airway vascular leakage is mediated by specific receptors but not by products of arachidonic acid metabolism or by platelets. Increased airway microvascular leakage induced by PAF may lead to plasma extravasation and airway edema, factors that may contribute to the airway narrowing and hyperresponsiveness induced by PAF.

Polydatin Attenuates Carbachol-induced Contraction of Guinea Pig Gallbladder

2019 ◽  
Vol 18 (1) ◽  
pp. 34-38
Author(s):  
Chen Lei ◽  
Pan Xiang ◽  
Shen Yonggang ◽  
Song Kai ◽  
Zhong Xingguo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Guinea Pig ◽  
Smooth Muscles ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Dependent Manner ◽  
Underlying Mechanisms ◽  
Dose Dependent

The aim of this study was to determine whether polydatin, a glucoside of resveratrol isolated from the root of Polygonum cuspidatum, warranted development as a potential therapeutic for ameliorating the pain originating from gallbladder spasm disorders and the underlying mechanisms. Guinea pig gallbladder smooth muscles were treated with polydatin and specific inhibitors to explore the mechanisms underpinning polydatin-induced relaxation of carbachol-precontracted guinea pig gallbladder. Our results shown that polydatin relaxed carbachol-induced contraction in a dose-dependent manner through the nitric oxide/cyclic guanosine monophosphate/protein kinase G and the cyclic adenosine monophosphate/protein kinase A signaling pathways as well as the myosin light chain kinase and potassium channels. Our findings suggested that there was value in further exploring the potential therapeutic use of polydatin in gallbladder spasm disorders.

Nicotine Suppression of Gustatory Responses of Neurons in the Nucleus of the Solitary Tract

2006 ◽  
Vol 96 (4) ◽  
pp. 1877-1886 ◽  
Author(s):  
Christopher T. Simons ◽  
Yves Boucher ◽  
Mirela Iodi Carstens ◽  
E. Carstens
Keyword(s):  
Monosodium Glutamate ◽  
Plasma Extravasation ◽  
Dependent Manner ◽  
Evoked Responses ◽  
Solitary Tract ◽  
Depressant Effect ◽  
Tongue Surface ◽  
Single Unit Recordings ◽  
Gustatory Neurons ◽  
Dose Dependent

This study investigated effects of nicotine applied to the tongue surface on responses of gustatory neurons in the nucleus of the solitary tract (NTS) in rats. In pentobarbital-anesthetized rats, single-unit recordings were made from NTS units responsive to one or more tastants (sucrose, NaCl, citric acid, monosodium glutamate, quinine). Application of nicotine (0.87, 8.7, or 600 mM) excited gustatory NTS units and significantly attenuated NTS unit responses to their preferred tastant in a dose-dependent manner. The depressant effect of nicotine was equivalent regardless of which tastant best excited the NTS unit. Nicotinic excitation of NTS units and depression of their tastant-evoked responses were both significantly attenuated by the nicotinic antagonist mecamylamine, which itself did not excite NTS units. In rats with bilateral trigeminal ganglionectomy, nicotine still excited nearly all NTS units but no longer depressed tastant-evoked responses. Nicotine did not elicit plasma extravasation when applied to the tongue. The results indicate that nicotine directly excites NTS units by gustatory nerves and inhibits their tastant-evoked responses by a nicotinic acetylcholine receptor-mediated excitation of trigeminal afferents that inhibit NTS units centrally.

scholarly journals Effects of esculentoside A on turnour necrosis factor production by mice peritoneal macrophages

1992 ◽  
Vol 1 (6) ◽  
pp. 375-377 ◽  
Author(s):  
Fang Jun ◽  
Zheng Qin Yue ◽  
Wang Hong Bin ◽  
Ju Dian Wen ◽  
Yi Yang Hua
Keyword(s):  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Inflammatory Mediator ◽  
Platelet Activating Factor ◽  
Peritoneal Macrophages ◽  
Dependent Manner ◽  
Anti Inflammatory ◽  
Dose Dependent ◽  
Necrosis Factor ◽  
Inflammatory Effect

Esculentoside A (EsA) is a saponin isolated from the roots of Phytolacca esculenta. Previous experiments showed that it had strong anti-inflammatory effects. Tumour necrosis factor (TNF) is an important inflammatory mediator. In order to study the mechanism of the anti-inflammatory effect of EsA, it was determined whether TNF production from macrophages was altered by EsA under lipopolysaccharide (LPS) stimulated conditions. EsA was found to decrease both extracellular and cell associated TNF production in a dose dependent manner at concentrations higher than 1 μmol/l EsA. Previous studies have showed that EsA reduced the releasing of platelet activating factor (PAF) from rat macrophages. The reducing effects of EsA on the release of TNF and PAF may explain its anti-inflammatory effect.

Neurokinin receptor mediated plasma extravasation in guinea pig and rat airways: comparison of 125I-labelled human fibrinogen and 99mTc-labelIed human serum albumin as markers of leakage

1993 ◽  
Vol 71 (7) ◽  
pp. 506-511 ◽  
Author(s):  
Christine Tousignant ◽  
Chi-Chung Chan ◽  
Donna Young ◽  
Diane Guevremont ◽  
Ian W. Rodger
Keyword(s):  
Human Serum Albumin ◽  
Guinea Pig ◽  
Serum Albumin ◽  
Human Serum ◽  
Plasma Extravasation ◽  
Human Fibrinogen ◽  
Protein Extravasation ◽  
Neurokinin Receptor ◽  
Lower Airways ◽  
Dose Dependent

In the present study we have characterized NK-1 and NK-2 receptor induced microvascular leakage in guinea pig and rat airways, using 125I-labelled human fibrinogen ([125I]FN) versus 99mTc-labelled human serum albumin ([99mTc]HSA) as markers for plasma protein extravasation. Intravenous administration of the selective NK-1 agonist [Sar9, Met(O2)11]SP (1 nmol kg−1) caused a dose-dependent increase of [125I]FN extravasation in guinea pig trachea, main bronchi, secondary bronchi, and intraparenchymal airways. Extravasation of [125I]FN increased by up to 192 (trachea), 284 (main bronchi), 368 (secondary bronchi), and 271% (intraparenchymal bronchi) over control levels in these regions of the airways. Pretreatment of the animals with CP 99,994 and RP 67,580, two NK-1 nonpeptide antagonists, caused a dose-dependent inhibition of [Sar9, Met(O2)11]SP-induced leakage of [125I]FN. [Sar9, Met(O2)11]SP (1 nmol kg−1) did not induce specific leakage of [99mTc]HSA in the intraparenchymal bronchi. Specific NK-2 receptor induced leakage was detected in the lower airways but only when using [125I]FN as a marker. We have also compared the ability of CP 99,994 and RP 67,580 to inhibit [Sar9, Met(O2)11]SP induced extravasation of [125I]FN in rat airways. CP 99,994 was 40–50 (tracheobronchial region) to 75 (lower airways) times more potent in the guinea pig than the rat airways. In contrast, RP 67,580 had higher affinity for rat airways compared with guinea pig airways. The results of this study highlight the superiority of [125I]FN as a sensitive marker of plasma extravasation over [99mTc]HSA. Furthermore, the results strongly suggest that both NK-1 and NK-2 receptors mediate plasma extravasation in the guinea pig lower airways and that NK-1 receptors are different in guinea pig and rat airways.Key words: Leakage, tachykinins, NK-1 and NK-2 receptors, airway, asthma.

scholarly journals Acetylcholinesterase and Butyrylcholinesterase Inhibitory Compounds from Corydalis Cava (Fumariaceae)

2011 ◽  
Vol 6 (5) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Jakub Chlebek ◽  
Kateřina Macáková ◽  
Lucie Cahlíková ◽  
Milan Kurfürst ◽  
Jiří Kuneš ◽  
...  
Keyword(s):  
Human Blood ◽  
Inhibitory Activity ◽  
Potent Inhibitor ◽  
The Other ◽  
Spectroscopic Techniques ◽  
Dependent Manner ◽  
Isoquinoline Alkaloids ◽  
Chemical Structures ◽  
Inhibitory Compounds ◽  
Dose Dependent

Tubers of Corydalis cava were extracted with ethanol and fractionated using n-hexane, chloroform and ethanol. Repeated column chromatography, preparative TLC and crystallization led to the isolation of fifteen isoquinoline alkaloids. The chemical structures of the isolated compounds were determined on the basis of spectroscopic techniques and by comparison with literature data. All isolated compounds were tested for human blood acetylcholinesterase (HuAChE) and human plasma butyrylcholinesterase (HuBuChE) inhibitory activity. (+)-Canadaline inhibited acetylcholinesterase as well as butyrylcholinesterase in a dose-dependent manner with IC50 values of 20.1 ± 1.1 μM and 85.2 ± 3.2 μM, respectively. (+)-Canadine, with an IC50 value of 12.4 ± 0.9 μM, was the most potent inhibitor of acetylcholinesterase, whilst (±)-corycavidine and (+)-bulbocapnine were effective inhibitors of butyrylcholinesterase with IC50 values of 46.2 ± 2.4 uM and 67.0 ± 2.1 μM, respectively. The other isolated alkaloids were considered inactive (IC50 > 100 μM).

scholarly journals Acetylcholinesterase and Butyrylcholinesterase Inhibitory Compounds from Chelidonium Majus (Papaveraceae)

2010 ◽  
Vol 5 (11) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Lucie Cahlíková ◽  
Lubomír Opletal ◽  
Milan Kurfürst ◽  
Kateřina Macáková ◽  
Andrea Kulhánková ◽  
...  
Keyword(s):  
Human Plasma ◽  
Human Blood ◽  
Inhibitory Activity ◽  
Dependent Manner ◽  
Isoquinoline Alkaloids ◽  
Chelidonium Majus ◽  
Aerial Parts ◽  
Naturally Occurring ◽  
Inhibitory Compounds ◽  
Dose Dependent

The roots and aerial parts of Chelidonium majus L. were extracted with EtOH and fractionated using CHCl3 and EtOH. Repeated column chromatography, preparative TLC and crystallization led to the isolation of five isoquinoline alkaloids, stylopine (3), chelidonine (4), homochelidonine (5), protopine (6), and allocryptopine (7), along with two isolation artifacts 6-ethoxydihydrosanguinarine (1) and 6-ethoxydihydrochelerythrine (2). All isolated compounds were tested for human blood acetylcholinesterase (HuAChE) and human plasma butyrylcholinesterase (HuBuChE) inhibitory activity. The isolation artifacts exhibited the highest activity against HuAChE and HuBuChE with IC50 values of 0.83 ± 0.04 μM and 4.20 ± 0.19 μM for 6-ethoxydihydrochelerythrine and 3.25 ± 0.24 μM and 4.51 ± 0.31 μM for 6-ethoxydihydrosanguinarine. The most active of the naturally-occurring alkaloids was chelidonine, which inhibited both HuAChE and HuBuChE in a dose-dependent manner with IC50 values of 26.8 ± 1.2 μM and 31.9 ± 1.4 μM, respectively.

Endothelium-dependent and -independent relaxations to adenosine in guinea pig aorta

1990 ◽  
Vol 259 (1) ◽  
pp. H62-H67 ◽  
Author(s):  
J. P. Headrick ◽  
R. M. Berne
Keyword(s):  
Guinea Pig ◽  
Sodium Nitroprusside ◽  
Maximal Response ◽  
Dependent Manner ◽  
Prostaglandin F2 Alpha ◽  
Endothelial Response ◽  
Alpha Response ◽  
Dose Dependent ◽  
Subtype 3 ◽  
Indomethacin Treatment

Effects of endothelial removal and hypoxia on responses to adenosine, 5'-(N-ethylcarboxamido)-adenosine (NECA), 2-chloroadenosine, N6-cyclohexyladenosine (CHA), sodium nitroprusside, and acetylcholine were examined in guinea pig aortic rings. Rings contracted with 2 microM prostaglandin F2 alpha (PGF2 alpha) relaxed in a dose-dependent manner in response to all drugs. The order of potency of adenosine compounds was NECA greater than 2-chloroadenosine greater than adenosine greater than CHA. Endothelial rubbing potentiated the PGF2 alpha response by 11 +/- 3%, eliminated the acetylcholine (ACh) response, but had no effect on nitroprusside and CHA responses. Responses to adenosine, NECA, and 2-chloroadenosine were significantly depressed by rubbing (P less than 0.05). Oxyhemoglobin (5 microM) and metyrapone (0.1 mM) reduced ACh responses in intact rings but had no effect on the adenosine and nitroprusside responses. Indomethacin treatment (10 microM) did not alter ACh, nitroprusside, or adenosine responses in intact rings. Hypoxia (10% O2) potentiated maximal responses to adenosine (+26 +/- 3%) and nitroprusside (+28 +/- 4%) in intact and rubbed rings and reduced the maximal response to ACh in intact rings (-28 +/- 3%). It is concluded that 1) adenosine mediates relaxation in guinea pig aorta by endothelial-dependent and -independent mechanisms, 2) receptors involved in both endothelial-dependent and -independent relaxations are characteristic of the A2 adenosine subtype, 3) the endothelial response appears unrelated to EDRF or prostanoid release, and 4) the adenosine response is significantly potentiated by hypoxia.

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