Study Of Blood Vessels Research Articles

Role of BKCa channels in smooth muscle cells of mesenteric artery from type 1 diabetic rats

High conductance calcium‐activated potassium channels (BKCa) play a very important role in the regulation of arterial vascular tone through the hyperpolarization of the cell membrane. Diverse studies in blood vessels from different vascular beds in animal models with type I and II diabetes mellitus (DM) as well as in patients with type II diabetes have shown a decrease in the BK channels functional response which is probably related with cardiovascular complications secondary to this pathology that is the main cause of mortality in these patients.ObjectiveTo explore the expression and role of the BKCa channels in the contractility of the Mesenteric artery of Type I diabetic rats induced with streptozotocin.MethodsWe conducted isometric tension experiments in mesenteric artery rings (>500) to evaluate the function of the BKCa channel when pharmacologically activated with NS1619, a specific activator drug for this channel, or inhibiting it with Iberotoxin (Ibtx) a toxin that specifically blocks these channels. And with the purpose of knowing if BKCa channels are expressed in these arterial beds we conducted inmunofluorescence studies.ResultsWe observerd a small but not significant response to both activator and inhibitor of the BKCa channels in both control and experimental groups. The inmunofluorescence images indicated that the alfa subunit (the pore subunit) and beta 1 (modulator of the BKCa channel activity) are mostly expressed intracelullarly in endothelial cells and in the smooth muscle of these vessels. This suggests that the lack of response to NS1619 and IBtx is due to the fact that the channel is intracelullar and therefore its participation in the determination of muscle tone of the mesenteric artery is not significant. In contrast, preliminary results of isometric tension in first‐order rat mesenteric artery rings (approximately 400 μm in diameter), show a great participation of the BKCa channels in the regulation of the arterial tone of these vessels, by diminishing in about 80% the tension originated when contracting said rings with phenylephrine.ConclusionsBased on these results, we can conclude at present that the BKCa channels have a greater participation in the maintenance of muscle tone of small arteries (resistance) but not in big arteries (conductive) and that the type I diabetes does not affect the BKCa function in large conduncance arteries.Support or Funding InformationSupported by Conacyt 223350 to RETThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Vascular Stress Analysis During in Vivo Intravascular Optical Coherence Tomography Imaging

Intravascular optical coherence tomography (IVOCT) has been employed to clinical coronary imaging for several years. But the influence of flushing and OCT catheter to the blood vessel biomechanical properties have not been studied. In this paper, IVOCT imaging is integrated with the fluid-structure interaction (FSI) simulation to study the blood flow velocity and the stress distribution of a porcine carotid artery during IVOCT imaging. 3D geometric model is built based on the in vivo OCT images, and a hyperelastic model is employed for the material properties of the vascular wall. The blood flow profile and wall stress distributions under various imaging condition are obtained. This study is helpful for the biomechanical property studies of blood vessels and the clinical treatment of vascular diseases.

The Study of Blood Vessels of Submandibular Gland and Urinary Bladder in Rats Using an Original Morphometric Analysis

The objective of the study is to elucidate the factors influencing treatment compliance of asthmatic patients and to introduce the measures which will facilitate rise of the compliance indices.Materials and methods. There were examined 104 patients from 18-50 years old. For the study management there were formed two groups with main one comprising 51 patients undergoing combined basic medication and allergen specific immunotherapy. The second, control group, included 53 patients who refused to undergo allergen specific immunotherapy and they received only basic medication-assisted treatment. The follow-up of the patients was conducted during a year. To determinate treatment compliance there was used own questionnaire and the control of treatment efficacy was done on the grounds of Asthma Control Test and Patient Quality of Life Questionnaire.Findings of the study and their discussion. At the beginning of the study the medium index of the patients’ treatment compliance was low in both groups. During each doctor’s visiting there were checked and worked out patients’ practical skills on accurate drug administration and control over treatment handling as well as conducting of monitoring and modification of triggers (the need in smoking cessation, active motion and bodily exercises performance, hypoallergic diet abiding, etc. was explained) and comorbidity treatment. Within three months the indices increased in both groups and some increase remained six and even twelve months after. Improvement in patients’ indices of treatment compliance was accompanied by the better performance of treatment control and quality of life. During the study the majority of patients of the main group managed to reduce a daily dose of inhaled corticosteroids and long-acting b2-agonists.Conclusion. The conducted study shows that after 12 months the indices of patients’ treatment compliance, ability to control asthma and quality of life increased in both groups while the triggers were decreased (by means of smoking cessation, comorbidity management and accommodation ecological factors control). At the same time, better results (bronchial asthma manageability, basic treatment volume decrease) were received in the group of patients with allergen-specific immunotherapy treatment application.

Evaluación de medios de contraste en angiografía arterial y sus capacidades de atenuación del haz

Many studies have focused on the pharmacokinetics of iodinated contrast media. Most show how the enhancement curve of a parenchymal organ is a function of some parameters, such as cardiac output, rate of infusion, the diameter of the arterial needle, etc. It is also able to establish that differences in wash-in and wash-out compared to the parenchyma are an expression of abnormality.In angiography the most important is dynamics of the contrast medium and its ability to attenuate the radiation. The fluid dynamics depends on the density, viscosity, temperature, and water solubility of the contrast media. The study of blood vessels is obtained by direct infusion, so the complete filling is important for a proper assessment of the diameters and consequently the patency. Radio-opacity features appear to be particularly important in coronary angiography, and despite being a “quantitative” method, with a good injection “qualitative” information can also be obtained.

Microwave irradiation for fixation and immunostaining of endothelial cells in situ

Using microwave irradiation during tissue fixation and immunostaining reduces sample preparation time and facilitates penetration of fixatives and antibody solutions into the tissues. This results in improved fixation and reduction of non-specific binding of antibodies, respectively. Experimental analyses of endothelial cells in blood vessels in situ have been limited because of the difficulty of tissue preparation. We report here a technique using intermittent microwave irradiation for blood vessel fixation and immunostaining the fixed tissues. Intermittent microwave irradiation during fixation reduced blood vessel contraction and resulted in well preserved morphology of blood vessels, especially the endothelial cells. Microwave irradiation also reduced non-specific binding of fluorescein-labeled antibodies. These microwave irradiation-assisted techniques are useful for analysis of endothelial cell function and for pathological study of blood vessels in situ.

ウシ黄体における発情周期を通じた血管分布変化および中期黄体内血管分布に及ぼす PGF2α の影響

ウシ黄体における発情周期を通じた血管分布変化および中期黄体内血管分布に及ぼす PGF2α の影響

The role of pericytes in blood-vessel formation and maintenance

Blood vessels are composed of two interacting cell types. Endothelial cells form the inner lining of the vessel wall, and perivascular cells--referred to as pericytes, vascular smooth muscle cells or mural cells--envelop the surface of the vascular tube. Over the last decades, studies of blood vessels have concentrated mainly on the endothelial cell component, especially when the first angiogenic factors were discovered, while the interest in pericytes has lagged behind. Pericytes are, however, functionally significant; when vessels lose pericytes, they become hemorrhagic and hyperdilated, which leads to conditions such as edema, diabetic retinopathy, and even embryonic lethality. Recently, pericytes have gained new attention as functional and critical contributors to tumor angiogenesis and therefore as potential new targets for antiangiogenic therapies. Pericytes are complex. Their ontogeny is not completely understood, and they perform various functions throughout the body. This review article describes the current knowledge about the nature of pericytes and their functions during vessel growth, vessel maintenance, and pathological angiogenesis.

Attenuation of the development of DOCA salt hypertension by a high Mn intake in the rat

The effects of a high Mn intake on blood pressure, vascular reactivity and central catecholamine levels were studied in DOCA salt-hypertensive rats. High Mn intake inhibited blood pressure elevation in DOCA salt rats but did not modify it in normotensive rats. The blood pressure-lowering effect of Mn was associated with inhibited cardiac hypertrophy and increased natriuresis. Pharmacological studies in blood vessels showed that high Mn intake normalized vasoconstriction and sensitivity to norepinephrine of isolated and perfused mesenteric vascular beds from DOCA salt rats. Furthermore, high Mn intake improved the endothelium- and NO-dependent relaxation in isolated aortae from DOCA salt-hypertensive rats but not in those from normotensive rats. Norepinephrine levels were higher in the hypothalamus of DOCA salt-hypertensive rats than in those of normotensive rats, and high Mn intake decreased norepinephrine levels in hypothalamus of DOCA salt rats. In conclusion, a high Mn intake attenuated the development of hypertension with beneficial vascular and central effects. Mechanisms related to the pathophysiological development of DOCA salt hypertension may be involved.

X-ray phase-contrast method and its application to the study of blood vessels with a model object

Studies of the phase-contrast method are reviewed. The principles of phase-contrast image formation are considered. The potentialities of the method are demonstrated using a model object as an example: a capillary tube filled with air and paraffin.

Comparative evaluation of blood vessels in serous tumors of the ovaries by color Doppler mapping and morphometry.

Morphometric study of blood vessels in serous tumors of the ovaries was carried out. Vascularization of benign, borderline, and malignant tumors is different, which agrees with the data of color Doppler mapping. Pronounced morphological changes in vascular wall (degenerative changes, sclerosis, and hyalinosis) were detected mainly in borderline and malignant tumors.

Endothelial Injury of Capillaries in the Stria Vascularis of Guinea Pigs Treated with Cisplatin and Gentamicin

The drugs cisplatin and gentamicin are used for treatment of various cancer patients suffering from infection. The authors report a detailed electron microscopic study of blood vessels in stria vascularis of guinea pigs after treatment with cisplatin alone and in combination with gentamicin. The most distinctive features expressing endothelial cellular injury were mitochondrial, including occasional paracrystalline inclusions; electron-lucent foci with depleted organelles; intracytoplasmic vacuole formations; lipid bodies; cytoplasmic extrusions located on the luminal surface; and severe luminal constriction of part of the vessels from animals treated with the combined drugs. The study suggests that the damage to strial capillaries due to treatment with cisplatin alone and in combination with gentamicin may contribute to the injurious effects of these drugs on the strial tissue. Furthermore, the results of this study may enlarge the awareness of the potential vascular damage and vascular complications in additional body systems after medical use of cisplatin alone or in combination with gentamicin.

Vascular α-adrenoceptors: from the gene to the human

Adrenoceptors can be subdivided into three major types, the alpha 1-, alpha 2-, and beta-adrenoceptors. Each of these types can be further subdivided into three subtypes, based on pharmacological characteristics. Molecular cloning techniques have supported this subclassification. Recent data now suggest that alpha-adrenoceptor subtypes identified by pharmacological and molecular techniques correspond well, although species orthologs of several adrenoceptor subtypes have been identified. The secondary structure of the adrenoceptors has been elucidated and correlated with their interaction with second messenger molecules. alpha 1-Adrenoceptors, beta-adrenoceptors, and alpha 2-adrenoceptors mediate their actions through stimulation of inositol phosphate release, stimulation of adenylate cyclase, and inhibition of adenylate cyclase, respectively. Site-directed mutagenesis and the preparation of chimeric receptors have located the site of receptor--second messenger interaction to the third intracellular loop for each of these adrenoceptors. While subtypes of each of these classes all interact with the same second messenger, studies with recombinant alpha 2-adrenoceptors show subtype-related differences in receptor--second messenger interaction. Multiple alpha-adrenoceptor subtypes are expressed in vascular smooth muscle and are involved in various aspects of blood vessel function, including contraction, cellular growth, and proliferation. Various physiological factors can selectively influence responses to a particular subtype, and the relative roles of each subtype can vary between vascular beds and along an individual blood vessel as its caliber changes. Functional studies in blood vessels suggest the presence of additional alpha-adrenoceptor subtypes not yet identified via molecular techniques. Optimization of the therapeutic profile of an alpha-adrenoceptor antagonist may be possible via enhancement of selectivity for a particular subtype or by design of a specific profile of affinity for the individual subtypes.

Fractures du pôle proximal du scaphoïde Entité anatomo-clinique et thérapeutique

The authors present their anatomical and clinical findings concerning fractures and nonunions of the carpal scaphoid. They stress the proximal pole type I et II of the Schernberg (type C of Herbert) classification, and they suggest isolation of an anatomical entity, by the study of blood vessels, the ligament connections, and especially the pathomechanics as well as a clinical entity, by the mechanism of fracture and the surgical treatment, emphasizing the proximo-distal screwing, with excellent results. They present a series of 29 patients, with type I or II proximal fractures, either fresh or non-unions.

Plurivesicular nerve endings in the pulmonary artery.

PREVIOUS electron microscopic studies of blood vessels have failed to reveal “nerve endings” or synaptic regions within the muscularis1–4 although small bundles of mye-linated and unmyelinated axons have been clearly seen in the adventitia. The specific histological fluorescence method of Falck and Hillarp5 for catecholamines has provided morphological evidence for the intraneuronal, varicose distribution of the adrenergic transmitter in blood vessels6. While electron microscopic details are available on the terminal autonomic innervation of non-vascular smooth muscle7–10, the identification of comparable neuro-effector relationships in blood vessels is lacking, apart from the preliminary observations of de Robertis and de Iraldi11.

Study of blood vessels on cortex of living mammalian brain—description of technique

Study of blood vessels on cortex of living mammalian brain—description of technique

Use of cyanol in the study of blood-vessels in sheep skin.

As one approach to the problem of the nourishment of the growing wool fibre in its follicle, a detailed study of the distribution of blood-vessels in the skin of sheep and the blood supply to the wool follicle has been commenced in these laboratories.