Animals ; Endothelium, Vascular ; physiology ; Gene Expression Regulation ; Humans ; MicroRNAs ; physiology

The vascular endothelium is a dynamic structure responsible for the separation and regulated movement of biological material between circulation and interstitial fluid. Hormones and nutrients can move across the endothelium either via a transcellular or paracellular route. Transcellular endothelial transport is well understood and broadly acknowledged to play an important role in the normal and abnormal physiology of endothelial function. However, less is known about the role of the paracellular route. Although the concept of endothelial dysfunction in diabetes is now widely accepted, we suggest that alterations in paracellular transport should be studied in greater detail and incorporated into this model. In this review we provide an overview of endothelial paracellular permeability and discuss its potential importance in contributing to the development of diabetes and associated complications. Accordingly, we also contend that if better understood, altered endothelial paracellular permeability could be considered as a potential therapeutic target for diabetes.
Adherens Junctions ; Adiponectin ; Endothelium ; Endothelium, Vascular ; Extracellular Fluid ; Insulin ; Permeability ; Physiology ; Tight Junctions

Antiendothelial cell antibodies (AECA) have been detected in the sera of patients of autoimmune diseases showing vasculitis. Using IgM-ELISA, we found AECA in 42 (56%) of 75 sera samples from patients with Behcet's disease in a previous study. All of the 15 AECA-positive sera of Behcet's disease patients had an increased expression of the intercellular cell adhesion molecule-1 (ICAM-1), 93.3% of the sera induced the vascular cell adhesion molecule-1 (VCAM-1), and 100% of the serum induced the E-selectin molecule on human dermal microvascular endothelial cells (HDMEC). After stimulation of HDMEC with AECA-positive sera of Behcet's disease patients, the expression of ICAM-1 and VCAM-1 on HDMEC increased significantly at 4 hours, reaching a peak at 16 hours. Expression of E-selectin was induced at 1 hour after stimulation with a peak at 4 hours and it decreased thereafter. Adherence of T lymphocytes to HDMEC increased significantly after stimulation with AECA-positive sera from Behcet's disease patients. Also, the adherence of T lymphocytes to HDMEC increased at 4 hours and returned to its normal level at 48 hours. These results show that AECA-positive sera of Behcet's disease patients are capable of activating HDMEC to promote the adherence of T lymphocytes to increase the expression of ICAM-1, VCAM-1, and E-selectin on the cell surfaces. The whole process may play an important role in the pathogenesis of vasculitis in Behcet's disease.
Antibodies/physiology* ; Antibodies/blood ; Behcet's Syndrome/immunology ; Behcet's Syndrome/blood* ; Blood Physiology ; Cell Adhesion/physiology ; Cells, Cultured ; Endothelium, Vascular/physiology* ; Endothelium, Vascular/immunology* ; Endothelium, Vascular/cytology ; Human ; Microcirculation/physiology ; Skin/blood supply* ; T-Lymphocytes/physiology*

OBJECTIVETo explore the potential mechanism of breakthrough bleeding associated with progestin with in vitro methods.

METHODSThe isolation and culture of human endometrial endothelial cells (HEECs) was performed with the method established in our laboratory. The content and activity of urokinase-type plasminogen activator (uPA) and the content of plasminogen activator inhibitor-1 (PAI-1) in cell supernatants after incubated with different concentrations of progesterone (0-5 micromol/L) and 17beta-estradiol (0, 0.1, or 1 nmol/L) were measured by method of ELISA. Apoptosis rate of HEECs was measured by flow cytometry. Viable cell count was measured by MTT.

RESULTSThe increased level of progesterone (0.5-5 micromol/L) combined with 17beta-estradiol elevated content and activity of uPA while the production of PAI-1 remained unchanged. The apoptosis of HEECs was inhibited along with the increment of total viable cell counts at higher concentrations of progesterone with 17beta-estradiol.

CONCLUSIONThe inhibition of apoptosis and increased content and activity of uPA may contribute to the occurrence of irregular bleeding associated with progestin use to some extent

Apoptosis ; drug effects ; physiology ; Endometrium ; cytology ; physiology ; Endothelium ; cytology ; physiology ; Estradiol ; pharmacology ; Female ; Humans ; Metrorrhagia ; etiology ; Progestins ; physiology

To explore the changes of wall shear stress(WSS) effect on arterial endothelial cell(EC) apoptosis after reducing arterial blood flow. The reducing flow model was established in 60 rabbits. Endothelial stretched preparations were made at 8 different time intervals from 0 to 30 days. The apoptosis rate of arterial endothelial cells (AEC) was measured with TdT-mediated dUTP-biotin nick end labeling(TUNEL) method. The results showed that the apoptosis rate of AEC was significantly higher from 1 day to 7 days after decreasing WSS than that of control, which peaked on day 3. While with progressively increasing in WSS, the apoptosis rate restored to the level of control from 14 days to 30 days. These suggest that the apoptosis state of AEC might be markedly influenced by the changes of WSS. The persist decreasing of WSS may be the important factor which induces the cell apoptosis.
Animals ; Apoptosis ; Arteries ; cytology ; physiology ; Endothelium, Vascular ; cytology ; physiology ; Male ; Rabbits ; Regional Blood Flow ; Shear Strength

It is known that penile erection is mediated primarily through the release of a nonadrenergic noncholinergic (NANC) neurotransmitter which has been recently identified as nitric oxide (NO). To evaluate whether the endothelium is involved in neurally mediated relaxation in corpus cavernosum, we determined electrical field stimulation (EFS) induced relaxation in both the presence and absence of endothelium, and we tested the effect of an inhibitor of NO synthase, NG-nitro-L-arginine (NOARG), in the absence of endothelium to examine if de-endothelialized tissue can still generate NO. Isolated corpus cavernosal strips from New Zealand White rabbits were used for isometric tension study using organ chambers. The endothelium was removed through denuding tissue. After the tissue was contracted with norepinephrine, EFS was performed at frequencies of 5, 15 and 40 Hz in the presence of guanethidine and atropine to evaluate NANC-selective nerural relaxation. The relaxation induced by EFS was observed after preincubation with NOARG(10(-4) M) for 30 minutes. L-arginine (10(-3) M) was then added for 30 minutes in the presence of NOARG before a second set of EFS studies were performed. Following norepinephrine precontraction, EFS relaxed corporal strips in both the intact and de-endothelialized strips. However, deendothelialization significantly impaired EFS induced relaxation (p< 0.05). NOARG attenuated relaxation induced by EFS and the addition of L-arginine reversed the inhibitory effect of NOARG in the strips with endothelium. In the strips without endothelium, NOARG still inhibited EFS induced relaxation. This relaxation was reversed by the addition of L-arginine.
Animal ; Endothelium/physiology ; Male ; Muscle Relaxation ; Neurons/metabolism ; Nitric Oxide/*physiology ; *Penile Erection ; Penis/innervation/*physiology ; Rabbits

Based on the morphology and function of lymphatic vessel, and on the achievements of researches in the regulatory mechanism of lymphatic circulation, we fully considered the dynamic interaction of blood, interstitial fluid and lymph fluid; then we imitated and used Sungawa's method of analyzing the heart output, and finally set up a dynamic model for describing lymphatic circulation. Comparison of our calculating results with the data from Ikomi's experiment showed that they were identical, thus indicating that our model is of value in explaining the dynamic mechanism of lymphatic circulation. In this paper is especially calculated the relationship between lymph flow and massage frequency, which is useful for analyzing the effect of massage on the lymph flow rate with respect to this model.
Animals ; Computer Simulation ; Endothelium, Lymphatic ; cytology ; physiology ; Humans ; Lymph ; physiology ; Lymphatic Vessels ; physiology ; Models, Biological ; Nonlinear Dynamics ; Pressure ; Rabbits ; Rheology

BACKGROUNDNon-heart-beating donor lung has been a promising source of lung transplantation. Many studies on non-heart-beating donor lungs are based on animal lung transplantation. In this study, we assessed by organ bath the effect of one-hour warm ischemia on the non-heart-beating donor lung in terms of the integrity of contractile and relaxant functions and tissue structures of pulmonic arteries and bronchi.

METHODSSixteen Swedish pigs were randomly classified into two groups: heart-beating donor group and 1-hour warm ischemia non-heart-beating donor group. Pulmonic and bronchial rings were taken from the isolated left lungs of the pigs. The pulmonic rings were stimulated by U-46619 (5.7 mol/L) and acetylcholine (10(-4) mmol/L) to assess the contractile abilities of smooth muscle and the endothelium-dependent relaxation response, respectively. As such, acetylcholine (10(-5) mmol/L) and natrium arachidonic acid (0.01%) were used to detect the contraction of bronchial smooth muscle and epithelium-dependent relaxation response. Meanwhile, the variances of precontraction tension of control groups were recorded to measure whether there was spontaneous relaxation during endothelium/epithelium-dependent relaxation course. Finally, papaverine solution (10(-4) mmol/L) was used to detect the non-endothelium/epithelium-dependent relaxant abilities of pulmonic and bronchial smooth muscles.

RESULTSThere was no significant difference in the tension values of precontraction of pulmonic rings (P > 0.05), endothelium-dependent relaxation (P > 0.05), precontraction of bronchial rings (P > 0.05) and epithelium-dependent relaxation (P > 0.05) between the heart-beating donor group and the 1-hour warm ischemia non-heart-beating donor group. And the pulmonic and bronchial rings of each subgroup B had no spontaneous relaxation. Finally, papaverine solution relaxed the smooth muscle of all the rings completely.

CONCLUSIONSThe results of this experiment suggest that the contractile and relaxant functions and tissue structures of pulmonic arteries and bronchi are not damaged after warm ischemia for 1 hour, and support the further study of non-heart-beating donor lung.

Animals ; Bronchi ; physiology ; Endothelium, Vascular ; physiology ; Lung Transplantation ; Pulmonary Artery ; physiology ; Swine ; Tissue Donors ; Vasodilation ; Warm Ischemia ; methods

Endothelial progenitor cells (EPCs) are immature endothelial cells which have the capacity to proliferate, migrate and differentiate into mature endothelial cells from bone marrow to the peripheral circulation. EPCs have been shown to participate in postnatal endothelial repair and neovascularization of ischemic organs, and have been used as a new source of seeded cells in vascular tissue engineering. In this review, we focus on the origin, identification, property and function of EPCs as well as their application in vascular tissue engineering.
Animals ; Blood Vessels ; physiopathology ; Endothelial Cells ; cytology ; physiology ; Endothelium, Vascular ; pathology ; physiology ; Humans ; Neovascularization, Physiologic ; physiology ; Recovery of Function ; physiology ; Stem Cells ; cytology ; physiology ; Tissue Engineering ; methods

The coupling between the endothelium and blood flow is an important biomedical problem and has drawn extensive research. Endothelial cells are known to adapt their shapes and functions in response to applied shear flow. Shear Stress being regarded as a primary triggering signal for cellular remodeling, it is important to understand the interaction mechanism between applied shear flow and endothelial cells. In present study we have established a theoretical model to simulate the coupling between the deformation of an endothelial cell and applied shear flow. A two dimensional computational fluid dynamic (CFD) is conducted to determine the local distributions of mechanical stress and pressure on cell surface. Our results show that: (1) the deformation of endothelial cell changes with alpha (corresponding to the shear stress imposed on cell surface by flow fluid). When alpha is greater than 0.021, the cell deformability increases greatly; (2) the distributions of stress and pressure on cell surface are not uniform, but the maximal shear stress and displacement are always at the top point of the cell. Meanwhile, we have measured the deformation of cultured human aortic endothelial cells (HAECs) exposed to shear flow by using a flow chamber. We found that the numerical results are well consistent with those of experiment. These results suggest that the non-uniformity distributions of mechanical stress and pressure on cell surface may play a particular role in the mechanism of cell activation and in the regulation of endothelial cells functions (modification of cytoskeleton, distributions of adhesion molecules, etc.). The present study offers a framework to facilitate the development of a comprehensive dynamic model for endothelial cells.
Aorta ; cytology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; physiology ; Humans ; Models, Cardiovascular ; Stress, Mechanical