scholarly journals The Effect of Prostaglandins G2, D2, E2, E1 and Arachidonic acid on Thrombus Formation in Vivo

1977 ◽  
Author(s):  
J. Westwick ◽  
G.P. Lewis
Keyword(s):  
Arachidonic Acid ◽  
Thrombus Formation ◽  
Cheek Pouch ◽  
Mural Thrombus ◽  
Hamster Cheek Pouch ◽  
Potent Vasodilator ◽  
High Doses

Arachidonic acid (AA) and prostaglandin (PG) G2 have been shown to he precursors of both pro-aggregatory and anti-aggregatory agents in vitro. If PGG2 is produced in thrombotic and inflammatory situations, it is important to know its effects on thrombus formation in vivo. Mural thrombus formation was induced in the arterioles (40-70 μm) of the hamster cheek pouch by combining micro-electrical damage with perivascular application of ADP (10-6M).PG or vehicle was applied perivascularly, followed 30 sec and 1 min later by electrical micro-damage and application of ADP (lOM). The vessel was observed and thrombus formation was quantitated by timing the adherence of thrombi for the following 10 nriruEach animal served as its own control and results were expressed as % difference (mean - s.e.) from control. PGGs, AA and PGE]_ produced a dose-related (12.5 - 1250 ng) inhibition (lO ± 8% - 90 ± 15%) of thrombus formation.Both PGG2 (Lewis, Vestwick & Williams, Br.J.Pharmac., 1977, in press) and AA induce a short-lasting vasoconstriction followed by vasodilatation. However, another potent vasodilator, PGE1, in a low Jose (125 ng) potentiated (49 - 20%) while high doses (1250 ng) produced a weak inhibition (15 ± 10%) of thrombus formation. PGD2 had little activity up to a concentration of I25O ng.These results demonstrate that AA and PGG2 can be converted to anti-thrombotic agents in vivo when applied perivascularly. Since PGD5 and PGE2 were not anti-thrombotic, it is possible that the observed effect was due to generation of prostacyclin.

Vasodilation elicited by liposomal VIP is unimpeded by anti-VIP antibody in hamster cheek pouch

1998 ◽  
Vol 275 (1) ◽  
pp. R56-R62 ◽  
Author(s):  
Hiroyuki Ikezaki ◽  
Sudhir Paul ◽  
Hayat Alkan-Önyüksel ◽  
Manisha Patel ◽  
Xiao-Pei Gao ◽  
...  
Keyword(s):  
Calcium Ionophore ◽  
Myeloma Cell ◽  
Cheek Pouch ◽  
Myeloma Cell Line ◽  
Hamster Cheek Pouch ◽  
High Affinity ◽  
Sterically Stabilized Liposomes

The purpose of this study was to determine whether a monoclonal anti-vasoactive intestinal peptide (VIP) antibody, which binds VIP with high affinity and specificity and catalyzes cleavage of the peptide in vitro, attenuates VIP vasorelaxation in vivo and, if so, whether insertion of VIP on the surface of sterically stabilized liposomes (SSL), which protects the peptide from trypsin- and plasma-catalyzed cleavage in vitro, curtails this response. Using intravital microscopy, we found that suffusion of monoclonal anti-VIP antibody (clone c23.5, IgG2ak), but not of nonimmune antibody (myeloma cell line UPC10, IgG2ak) or empty SSL, significantly attenuates VIP-induced vasodilation in the in situ hamster cheek pouch ( P < 0.05). By contrast, anti-VIP antibody has no significant effects on vasodilation elicited by isoproterenol, nitroglycerin, and calcium ionophore A-23187, agonists that activate intracellular effector systems in blood vessels that mediate, in part, VIP vasoreactivity. Suffusion of VIP on SSL, but not of empty SSL, restores the vasorelaxant effects of VIP in the presence of anti-VIP antibody. Collectively, these data suggest that VIP catalysis by high affinity and specific VIP autoantibodies displaying protease-like activity constitutes a novel mechanism whereby VIP vasoreactivity is regulated in vivo.

Ratiometric measurement of endothelial depolarization in arterioles with a potential-sensitive dye

1996 ◽  
Vol 270 (6) ◽  
pp. H2216-H2227 ◽  
Author(s):  
J. M. Beach ◽  
E. D. McGahren ◽  
J. Xia ◽  
B. R. Duling
Keyword(s):  
Membrane Potential ◽  
Fluorescence Emission ◽  
Cheek Pouch ◽  
Voltage Sensitivity ◽  
Hamster Cheek Pouch ◽  
Endothelial Cell Layer ◽  
Ratiometric Measurement ◽  
Length Constant

A fluorescence ratio technique based on the voltage-sensitive dye 1-(3-sulfonatopropyl)-8-[beta-[2-di-n-butylamino)-6-naphythyl++ +]vinyl] pyridinium betaine (di-8-ANEPPS)has been developed for recording membrane potential changes during vascular responses of arterioles. Perfusion of hamster cheek pouch arterioles with the dye labeled the endothelial cell layer. voltage responses from the endothelium of intact arterioles were determined by analysis of voltage-induced shifts in fluorescence emission wavelengths from dye spectra imaged from the vessel wall. Membrane depolarization caused the dye spectrum to shift toward blue wavelengths, with maximal fluorescence changes near 560 and 620 nm. In isolated nonperfused arterioles, comparison of continuous dual-wavelength recordings with simultaneous microelectrode recordings showed that the ratio of fluorescence intensities (fluorescence at 620 nm to fluorescence at 560 nm) accurately followed changes in membrane potential (6–21 mV) during vasoconstriction. The dye response was linear with respect to potential changes from -56 to -6 mV, with a voltage sensitivity of 9.7% change in the ratio per 100 mV. Membrane potential responses from in vitro and in vivo arterioles after potassium stimulation consisted of rapid ( < 0.5 -s) depolarization followed by slow repolarization over several seconds. Potassium-induced depolarizations were conducted along arterioles, and the values of the electrical length constant for conducted depolarization determined by optical and microelectrode methods were in agreement. We conclude that ratio analysis of di-8-ANEPPS fluorescence emission can be used to accurately record membrane potential changes on the time scale of seconds during vasomotor activity from arterioles.

scholarly journals Studies on drug absorption from oral cavity. II Influence of the unstirred water layer on absorption from hamster cheek pouch in vitro and in vivo.

1987 ◽  
Vol 10 (4) ◽  
pp. 180-187 ◽  
Author(s):  
YUJI KUROSAKI ◽  
SHINICHI HISAICHI ◽  
CHIEKO HAMADA ◽  
TAIJI NAKAYAMA ◽  
TOSHIKIRO KIMURA
Keyword(s):  
Oral Cavity ◽  
Drug Absorption ◽  
Water Layer ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch ◽  
Unstirred Water Layer

scholarly journals C1-esterase inhibitor treatment: preclinical safety aspects on the potential prothrombotic risk

2014 ◽  
Vol 112 (11) ◽  
pp. 960-971 ◽  
Author(s):  
Elmar Raquet ◽  
Marc Nolte ◽  
Frauke May ◽  
Jochen Müller-Cohrs ◽  
Jenny Björkqvist ◽  
...  
Keyword(s):  
Thrombus Formation ◽  
Venous Stasis ◽  
High Dose ◽  
In Vivo Models ◽  
C1 Esterase Inhibitor ◽  
Activity Measurements ◽  
High Doses ◽  
Esterase Inhibitor

SummaryHuman plasma-derived C1-esterase inhibitor (C1–INH) is an efficacious and safe treatment for hereditary angioedema. However, thrombotic events in subjects treated with C1–INH at recommended or offlabel, high doses have been reported. In this study, we addressed the potential prothrombotic risk of C1–INH treatment in high doses using a non-clinical rabbit model. Following intravenous infusion of C1–INH to rabbits at doses up to 800 IU/kg, the exposure and the pharmacodynamic efficacy of C1–INH in rabbits were confirmed by activity measurements of C1-esterase, and coagulation factors XIa and XIIa, respectively. Potential prothrombotic effects were assessed following induction of venous and arterial thrombosis using in vivo models of venous and arterial stasis, complemented by various in vitro assays of coagulation markers. Administration of C1–INH at doses up to 800 IU/ kg did not potentiate thrombus formation during venous stasis. In contrast, inhibition of arterial occlusion was observed upon C1–INH administration when compared with isotonic saline treatment, indicating antithrombotic rather than prothrombotic activity of high dose C1–INH treatment in vivo. This was further confirmed in vitro by decreased thrombin generation, increased activated partial thromboplastin time, clotting time and clot formation time, and inhibition of platelet aggregation. No relevant changes in fibrinolysis or in the levels of thrombin-antithrombin complexes, and prothrombin fragment 1+2 were observed upon high dose C1–INH treatment. The data suggest that treatment of healthy rabbits with high doses of C1–INH could potentially inhibit coagulation and thrombus formation rather than induce a prothrombotic risk.

Arteriolar reactivity in vivo is influenced by an intramural diffusion barrier

1990 ◽  
Vol 259 (2) ◽  
pp. H574-H581 ◽  
Author(s):  
M. J. Lew ◽  
B. R. Duling
Keyword(s):  
Diffusion Barrier ◽  
Vascular Reactivity ◽  
Pressor Response ◽  
Systemic Blood Pressure ◽  
Water Soluble ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch ◽  
Water Soluble Drugs

The endothelium of the hamster cheek pouch arteriole in vitro is able to greatly reduce the potency of luminally applied water-soluble drugs by acting as a barrier to diffusion from the lumen to the smooth muscle [Lew, Rivers, and Duling. Am. J. Physiol. 257 (Heart Circ. Physiol. 26): H10-H16, 1989]. Lipid-soluble drugs appear unaffected by the diffusion barrier, presumably because their ability to cross cell membranes allows them to freely cross the endothelium. We compared the effects of two alpha 1-adrenoceptor agonists, phenylephrine (water soluble) and SKF 89748A (lipid soluble), on systemic blood pressure and the arterioles of the hamster cheek pouch in vivo. Both agonists were able to activate the arterioles when applied topically to the outside of the arterioles (extraluminal application). The agonists were also injected as a brief bolus into the aortic arch at doses chosen to elicit similar peak pressor responses. At all levels of pressor response, the arteriolar responses to phenylephrine were smaller than those to SKF 89748A. In the cremasteric vasculature SKF 89748A was similarly found to be more effective in activating the arterioles after intravascular administration than was phenylephrine. We conclude that an intramural diffusion barrier exists in the arteriolar wall in vivo and that it can influence vascular reactivity.

Arteriolar smooth muscle Ca2+ dynamics during blood flow control in hamster cheek pouch

2006 ◽  
Vol 101 (1) ◽  
pp. 307-315 ◽  
Author(s):  
Johan Fredrik Brekke ◽  
William F. Jackson ◽  
Steven S. Segal
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Local Control ◽  
Cheek Pouch ◽  
Tissue Blood Flow ◽  
Hamster Cheek Pouch ◽  
Dye Loading ◽  
Blood Flow Control

Intracellular calcium concentration ([Ca2+]i) governs the contractile status of arteriolar smooth muscle cells (SMC). Although studied in vitro, little is known of SMC [Ca2+]i dynamics during the local control of blood flow. We tested the hypothesis that the rise and fall of SMC [Ca2+]i underlies arteriolar constriction and dilation in vivo. Aparenchymal segments of second-order arterioles (diameter 35 ± 2 μm) were prepared in the superfused cheek pouch of anesthetized hamsters ( n = 18) and perifused with the ratiometric dye fura PE-3 (AM) to load SMC (1 μM, 20 min). Resting SMC [Ca2+]i was 406 ± 37 nM. Elevating superfusate O2 from 0 to 21% produced constriction (11 ± 2 μm) that was unaffected by dye loading; [Ca2+]i increased by 108 ± 53 nM ( n = 6, P < 0.05). Cycling of [Ca2+]i during vasomotion (amplitude, 150 ± 53 nM; n = 4) preceded corresponding diameter changes (7 ± 1 μm) by ∼2 s. Microiontophoresis (1 μm pipette tip; 1 μA, 1 s) of phenylephrine (PE) transiently increased [Ca2+]i by 479 ± 64 nM ( n = 8, P < 0.05) with constriction (26 ± 3 μm). Flushing blood from the lumen with saline increased fluorescence at 510 nm by ∼45% during excitation at both 340 and 380 nm with no difference in resting [Ca2+]i, diameter or respective responses to PE ( n = 7). Acetylcholine microiontophoresis (1 μA, 1 s) transiently reduced resting SMC [Ca2+]i by 131 ± 21 nM ( n = 6, P < 0.05) with vasodilation (17 ± 1 μm). Superfusion of sodium nitroprusside (10 μM) transiently reduced SMC [Ca2+]i by 124 ± 18 nM ( n = 6, P < 0.05), whereas dilation (23 ± 5 μm) was sustained. Resolution of arteriolar SMC [Ca2+]i in vivo discriminates key signaling events that govern the local control of tissue blood flow.

Components of methacholine-initiated conducted vasodilation are unaffected by arteriolar pressure

1997 ◽  
Vol 272 (6) ◽  
pp. H2895-H2901 ◽  
Author(s):  
R. J. Rivers
Keyword(s):  
Average Length ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch ◽  
Electromechanical Transduction ◽  
Isolated Segment ◽  
A Site ◽  
Conducted Response

Conducted vasodilation occurs remotely from a site of microapplication of a drug. Intravascular pressure is required for a conducted response in vivo, yet in vitro studies in unpressurized arterioles show pressure is not essential. To determine how pressure affects conducted vasodilation, intra-arteriolar pressure was controlled within an in situ isolated segment (average length 950 +/- 96 microns, average baseline diameter 28 +/- 2.1 microns) of arterioles in the hamster cheek pouch. Methacholine (10(-4) M, 5 s) was microapplied either onto the isolated segment or remotely, with local and conducted vasodilation measured at both locations. Increasing pressure in the lumen of the segment (0-80 cmH2O) increased the segment local dilation to methacholine, and the segment-conducted dilation plateaued (at 4.1 +/- 0.8 micron) when segment pressure reached 20 cmH2O. Any local (16 +/- 1.5 microns) and conducted (4.4 +/- 1.3 microns) dilations viewed outside the segment were unaffected by segment pressure and persisted in its absence. Thus segment pressure affected only electromechanical transduction of the conducted response. Thus vasomotor signals move throughout the vasculature regardless of tone, but tone is essential to transduce the response.

scholarly journals Five steps in leukocyte extravasation in the microcirculation by chemoattractants

1992 ◽  
Vol 1 (6) ◽  
pp. 403-409 ◽  
Author(s):  
T. Oda ◽  
M. Katori ◽  
K. Hatanaka ◽  
S. Yamashina
Keyword(s):  
Cell Layer ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch ◽  
Extravascular Space ◽  
Vascular Lumen ◽  
Endothelial Cell Layer ◽  
Layer 4 ◽  
Leukocyte Extravasation

For in vivo study of the phenomena observed in vitro, PMN (polymorphonuclear leukocyte) extravasation was analysed quantitatively in the microcirculation of the hamster cheek pouch using a video system. Topical application of leukotriene B4or N-formyl-methionylleucyl- phenylalanine increased dose dependently the number of PMNs adhering to the venules. Eighty to 90% of the adhering PMNs disappeared from the vascular lumen into the venular wall within 10-12 rain after the adhesion. After PMNs had passed through the endothelial cell layer, they remained in the venular wall for more than 30 min after application of the chemoattractants and appeared in the extravascular space. Thus, the process could be divided into five steps: (1) rolling and (2) adhesion to the endothelium, (3) passage through the endothelial layer (4) remaining in the venular wall, and (5) passage through the basement membrane.

Myogenic response gradient in an arteriolar network

1993 ◽  
Vol 264 (6) ◽  
pp. H2168-H2179 ◽  
Author(s):  
M. J. Davis
Keyword(s):  
Fourth Order ◽  
In Vitro Study ◽  
Normal Pressure ◽  
Cheek Pouch ◽  
Myogenic Response ◽  
Hamster Cheek Pouch ◽  
Third Order ◽  
Response Gradient

Experiments were conducted to test the hypothesis that a longitudinal gradient in myogenic responsiveness exists within an arteriolar network. Single arterioles were dissected from the hamster cheek pouch, cannulated with micropipettes, and transferred to an inverted microscope for in vitro study. Pressure-diameter relationships of five branching orders of arterial vessels were measured in the presence of spontaneous vascular tone and after elimination of tone with a Ca(2+)-free solution containing nitroprusside. At luminal pressures matching those found in vivo, the diameters of the vessels with spontaneous tone were as follows: small arteries, 81 microns; first-order arterioles, 52 microns; second-order arterioles, 32 microns; third-order arterioles, 24 microns; and fourth-order arterioles, 11 microns. All branching orders of vessels exhibited true myogenic responses as indicated by negative slopes of their pressure-diameter relationships. Each vascular branching order exhibited its maximum myogenic responsiveness at a pressure near or just slightly higher than its normal pressure as measured in vivo. Relative myogenic responsiveness increased with decreasing vessel size down to the level of the second- and third-order arterioles, whereas fourth-order arterioles were substantially less responsive than third-order arterioles. A compilation of data from numerous in vivo and in vitro studies suggests that the same myogenic response pattern may be found in other vascular beds.

Antithrombotic Activity of Polydeoxyribonucleotides of Maml1Alian Origin (Laboratory Code: Fraction P) in Experimental Animals

1979 ◽  
Author(s):  
R. Niacia ◽  
H. Hantovani ◽  
G. Prino ◽  
R. Pescador ◽  
G.F. Nardi
Keyword(s):  
Ex Vivo ◽  
Thrombus Formation ◽  
Local Level ◽  
Femoral Vein ◽  
Dry Weight ◽  
Experimental Models ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch ◽  
Antithrombotic Activity

Fraction P(FP)is a polydeoxyribonucleotidic substance of mammalian 9rigin which was found able to ac tivat e the fibrinolytic system of some experimental animals.We have investigat ed the possible antithrombotic activity of FP in three different experimental models. In the col lagen-induced thrombosis of the rabbit femoral vein,pretreatment with FP i.v.(50, 100 or 200 mg/kg) reduced the thrombus dry weight by 427, (P < 0.005). 50% (P < 0.001) and 72% (P < 0.001), respectively; pretreatment with FP peros02.5, 25 or 50 mg/kg) decreased the thrombus dry weight by 22% (n.s.), 46% (P < 0.001) and 69% (P < 0.001), respectively. In the electrical l y induced thrombosis of rat carotid artery, pretreatment with FP i.v. (37.5, 75 or 150 mg/kg)reduced the fall in arterial surface temperature by 20%(P < 0.005), 62% (P < 0.025) and 86% (P < 0.001), respectively. In the hamster cheek pouch model, venular thrombosis induced by iontophoresis of ADP was inhibited by 85 %(P < 0.025) when the animals were pretreated with FP i.v. (2 mg/kg) or by 957, (P < 0.025) when FP was given per os (1 mg/kg). These antithrombotic effects lasted longer than the activation of fibrinolysis measured in ex vivo studies in the same animal species. This would suggest that a more complex mechanism(possibly including vascul ar factors at local level)could be responsible for the in vivo effect of FP as an inhibitor of thrombus formation.

Sign in / Sign up

Export Citation Format

Share Document