Effect of intravenous PDE-5 inhibitor Sildenafil on pulmonary microcirculation n

2006 ◽  
Vol 54 (S 1) ◽  
Author(s):  
V Milekhin ◽  
N Pizanis ◽  
R Maykan ◽  
G Butrous ◽  
H Jakob ◽  
...  
Keyword(s):  
Pulmonary Microcirculation

Proproliferative phenotype of pulmonary microvascular endothelial cells

2007 ◽  
Vol 292 (3) ◽  
pp. L671-L677 ◽  
Author(s):  
Victor Solodushko ◽  
Brian Fouty
Keyword(s):  
Endothelial Cells ◽  
Barrier Function ◽  
Pulmonary Arteries ◽  
D1 Protein ◽  
Coagulation Cascade ◽  
Microvascular Endothelial Cells ◽  
Significant Heterogeneity ◽  
Pulmonary Microvascular Endothelial Cells ◽  
Microvascular Endothelial ◽  
Pulmonary Microcirculation

Endothelial cells perform a number of important functions including release of vasodilators, control of the coagulation cascade, and restriction of solutes and fluid from the extravascular space. Regulation of fluid balance is of particular importance in the microcirculation of the lung where the loss of endothelial barrier function can lead to alveolar flooding and life-threatening hypoxemia. Significant heterogeneity exists between endothelial cells lining the microcirculation and cells from larger pulmonary arteries, however, and these differences may be relevant in restoring barrier function following vascular injury. Using well-defined populations of rat endothelial cells harvested from the pulmonary microcirculation [pulmonary microvascular endothelial cells (PMVEC)] and from larger pulmonary arteries [pulmonary artery endothelial cells (PAEC)], we compared their growth characteristics in low serum conditions. Withdrawal of serum inhibited proliferation and induced G0/G1 arrest in PAEC, whereas PMVEC failed to undergo G0/G1 arrest and continued to proliferate. Consistent with this observation, PMVEC had an increased cdk4 and cdk2 kinase activity with hyperphosphorylated (inactive) retinoblastoma (Rb) relative to PAEC as well as a threefold increase in cyclin D1 protein levels; overexpression of the cdk inhibitors p21Cip1/Waf1 and p27Kip1 induced G0/G1 arrest. While serum withdrawal failed to induce G0/G1 arrest in nonconfluent PMVEC, confluence was associated with hypophosphorylated Rb and growth arrest; loss of confluence led to resumption of growth. These data suggest that nonconfluent PMVEC continue to proliferate independently of growth factors. This proliferative characteristic may be important in restoring confluence (and barrier function) in the pulmonary microcirculation following endothelial injury.

A New Model for the Study of Pulmonary Microcirculation: Determination of Pulmonary Edema in Rats

1994 ◽  
Vol 57 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Victor H. Fingar ◽  
Scott W. Taber ◽  
T.Jeffery Wieman
Keyword(s):  
Pulmonary Edema ◽  
New Model ◽  
Pulmonary Microcirculation

The peculiarities of pulmonary macro- and microhemodynamics changes after treatment with agonists and blockers of cholinoceptors

2021 ◽  
Vol 20 (4) ◽  
pp. 35-44
Author(s):  
Vadim I. Evlakhov ◽  
Ilya Z. Poyassov ◽  
Tatiana P. Berezina
Keyword(s):  
Pulmonary Artery ◽  
Pulmonary Vascular Resistance ◽  
Pulmonary Artery Pressure ◽  
Vascular Resistance ◽  
Venous Return ◽  
Filtration Coefficient ◽  
Artery Pressure ◽  
Capillary Filtration ◽  
Capillary Filtration Coefficient ◽  
Pulmonary Microcirculation

Background. The pulmonary arterial and venous vessels are innervated by parasympathetic cholinergic nerves. However, the studies, performed on the isolated rings of pulmonary vessels, can not give answer to the question about the role of cholinergic mechanisms in the changes of pulmonary circulation in full measure. Aim. The comparative analysis of the changes of the pulmonary macro- and microhemodynamics after acetylcholine, atropine, pentamine and nitroglycerine treatment. Materials and methods. The study was carried out on the anesthetized rabbits in the condition of intact circulation with the measurement of the pulmonary artery pressure and flow, venae cavae flows, cardiac output, and also on isolated perfused lungs in situ with stabilized pulmonary flow with measurement of the perfused pulmonary artery pressure, capillary hydrostatic pressure, capillary filtration coefficient and calculation of the pulmonary vascular resistance, pre- and postcapillary resistances. Results. In the conditions of intact circulation after acetylcholine, pentamine and nitroglycerine treatment the pulmonary artery pressure and flow decreased, the pulmonary vascular resistance did not change as a result of decreasing of pulmonary artery flow and left atrial pressure due to diminution of venous return and venae cavaе flows. On perfused isolated lungs acetylcholine caused the increasing of pulmonary artery pressure, capillary hydrostatic pressure, pulmonary vascular resistance, pre- and postcapillary resistance and capillary filtration coefficient. After M-blocker atropine treatment the indicated above parameters of pulmonary microcirculation increased, on the contrary, after N-blocker pentamine treatment they decreased. Nitroglycerine infusion caused less decreasing of the parameters of pulmonary microcirculation in comparison with effects of pentamine, but capillary filtration coefficient decreased to a greater extent. These data indicate that nitroglycerine decreases endothelial permeability of pulmonary microvessels. Conclusion. After activation or blockade of cholinergic mechanisms in the condition of intact circulation the calculated parameter of pulmonary vascular resistance is depended from the ratio of the pulmonary artery pressure and flow and left atrial pressure, which are determined by the venous return. The different character of the changes of pulmonary microcirculatory parameters after M-blocker atropine and N-blocker pentamine treatment is evidence of reciprocal relations of M- and N-cholinoceptors in the nervous regulation of the pulmonary microcirculatory bed.

Pulmonary microcirculation: tubules rather than sheet and post

1982 ◽  
Vol 53 (2) ◽  
pp. 510-515 ◽  
Author(s):  
W. G. Guntheroth ◽  
D. L. Luchtel ◽  
I. Kawabori
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Critical Point ◽  
Ringer Solution ◽  
Basic Component ◽  
Pulmonary Vasculature ◽  
Critical Point Drying ◽  
Pulmonary Microcirculation ◽  
Scanning Electron

We examined latex casts of the pulmonary microcirculation with the scanning electron microscope (SEM). Mature rats were anesthetized and ventilated; the pulmonary vasculature was washed out with lactated Ringer solution and then filled with a mixture of Geon latexes. The airways were filled with glutaraldehyde with resulting transmural vascular pressures of 10 cmH2O. After critical-point drying and corrosive removal of the lung tissue, SEM studies of the vascular replicas revealed two distinct patterns of pulmonary microcirculation: 1) sparse, long, tubular capillaries that comprise the thin subpleural layer and appear as “filler” in the peribronchial spaces; and 2) alveolar microcirculation that is composed of tightly matted, intersecting tubules, shorter but of the same diameter as type 1, in spherical array in two layers. The alveolar capillaries at low magnification appear superficially as sheets; however, the detailed morphology is not consistent with the sheet-and-post model. We conclude that the basic component of the pulmonary microcirculation is tubular and not different from other capillary beds except in density.

Behavior of Stimulated Leukocytes in the Pulmonary Microcirculation of Perfused Rat Lungs

1997 ◽  
pp. 355-362 ◽  
Author(s):  
Takuya Aoki ◽  
Yukio Suzuki ◽  
Kazumi Nishio ◽  
Kouichi Suzuki ◽  
Atsusi Miyata ◽  
...  
Keyword(s):  
Rat Lungs ◽  
Pulmonary Microcirculation

scholarly journals Computational modeling of RBC and neutrophil transit through the pulmonary capillaries

2001 ◽  
Vol 90 (2) ◽  
pp. 545-564 ◽  
Author(s):  
Yaqi Huang ◽  
Claire M. Doerschuk ◽  
Roger D. Kamm
Keyword(s):  
Transpulmonary Pressure ◽  
Temporal Variations ◽  
Local Pressure ◽  
In Vivo Experiments ◽  
Pulmonary Capillaries ◽  
Transit Times ◽  
Capillary Bed ◽  
Pulmonary Microcirculation ◽  
Preferential Pathways

A computational model of the pulmonary microcirculation is developed and used to examine blood flow from arteriole to venule through a realistically complex alveolar capillary bed. Distributions of flow, hematocrit, and pressure are presented, showing the existence of preferential pathways through the system and of large segment-to-segment differences in all parameters, confirming and extending previous work. Red blood cell (RBC) and neutrophil transit are also analyzed, the latter drawing from previous studies of leukocyte aspiration into micropipettes. Transit time distributions are in good agreement with in vivo experiments, in particular showing that neutrophils are dramatically slowed relative to the flow of RBCs because of the need to contract and elongate to fit through narrower capillaries. Predicted neutrophil transit times depend on how the effective capillary diameter is defined. Transient blockage by a neutrophil can increase the local pressure drop across a segment by 100–300%, leading to temporal variations in flow and pressure as seen by videomicroscopy. All of these effects are modulated by changes in transpulmonary pressure and arteriolar pressure, although RBCs, neutrophils, and rigid microspheres all behave differently.

scholarly journals The soluble guanylate cyclase stimulator riociguat is the first-line therapy for chronic thromboembolic pulmonary hypertension patients

Kardiologiia ◽  
2020 ◽  
Vol 60 (8) ◽  
pp. 115-123
Author(s):  
Z. S. Valieva ◽  
S. E. Gratsianskaya ◽  
T. V. Martynyuk
Keyword(s):  
Pulmonary Hypertension ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
First Line ◽  
Pulmonary Thromboendarterectomy ◽  
First Line Therapy ◽  
Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Microcirculation

Chronic thromboembolic pulmonary hypertension (CTEPH) is a precapillary type of pulmonary hypertension with chronic obstruction of large and medium branches of pulmonary arteries along with secondary alterations in pulmonary microcirculation, which cause progressive increases in pulmonary vascular resistance and pulmonary arterial pressure and ensuing severe right heart dysfunction and heart failure. Pulmonary thromboendarterectomy (PTE) is the treatment of choice for CTEPH; however, this procedure is available not for all patients. Although the surgery performed in the conditions of centers with advanced experience generally shows good results, up to 40% of patients are technically inoperable or PTE is associated with a high risk of complications. At present, riociguat, the only officially approved drug from the class of soluble guanylate cyclase stimulators, is considered as a first-line treatment for inoperable and residual forms of STEPH. Introduction of riociguat to clinical practice can be called a real breakthrough in the treatment of patients with STEPH who cannot undergo PTE or those with relapse or persistent STEPH after the surgery.

Pulmonary Embolization of Bovine Collagen

2003 ◽  
Vol 127 (2) ◽  
pp. e67-e69
Author(s):  
Denis M. McCarthy ◽  
Mark Haas ◽  
Paul J. Thuluvath ◽  
Jeff F. Geschwind ◽  
Grover M. Hutchins ◽  
...  
Keyword(s):  
Collagen Matrix ◽  
Intratumoral Injection ◽  
Local Drug Delivery ◽  
Bovine Collagen ◽  
Effective Delivery ◽  
Autopsy Examination ◽  
Pulmonary Embolization ◽  
Pulmonary Microcirculation ◽  
Valuable Role

Abstract A bovine collagen matrix is sometimes used as a delivery medium during direct intratumoral injection of a chemotherapeutic agent. The bovine collagen enhances the dose and duration of local drug delivery and limits systemic toxicity. Although this strategy is advocated as a means of easy and effective delivery of chemotherapeutic drugs, the associated risks are not well defined. We report the case of a 71-year-old man with hepatocellular carcinoma who underwent weekly intratumoral injections of cisplatin in a bovine collagen matrix. During the third injection, he suddenly and unexpectedly underwent cardiac arrest and died. An autopsy disclosed diffuse occlusion of the pulmonary microcirculation by bovine collagen. The collagen emboli were associated with an inflammatory infiltrate typical of bovine collagen–induced hypersensitivity. This case identifies a fatal complication of intratumoral chemotherapy injections using a bovine collagen matrix, which does not appear to have been previously reported. This case underscores the valuable role of the traditional autopsy examination as a means of identifying possible complications of novel oncologic strategies, which are being rapidly developed and implemented.

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