[Measurements of caliber of blood vessels, blood pressure and blood flow of retina in cases of normal and late toxemia of pregnancy].
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Blood Circulation↗
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Influence of tensile strain on smooth muscle cell orientation in rat blood vessels.
Blood vessels are subject to tensile stress and associated strain which may influence the structure and organization of smooth muscle cells (SMCs) during physiological development and pathological remodeling. This study focused on the influence of the major tensile strain on the SMC orientation in the blood vessel wall. Several blood vessels, including the aorta, the mesenteric artery and vein, and the jugular vein of the rat were used to observe the normal distribution of tensile strains and SMC orientation; and a vein graft model was used to observe the influence of altered strain direction on the SMC orientation. The circumferential and longitudinal strains in these blood vessels were measured by using a biomechanical technique, and the SMC orientation was examined by fluorescent microscopy at times of 10, 20, and 30 days. Results showed that the SMCs were mainly oriented in the circumferential direction of straight blood vessels with an average angle of approximately 85 deg between the SMC axis and the vessel axis in all observed cases. The SMC orientation coincided with the principal direction of the circumferential strain, a major tensile strain, in the blood vessel wall. In vein grafts, the major tensile strain direction changed from the circumferential to the longitudinal direction at observation times of 10, 20, and 30 days after graft surgery. This change was associated with a decrease in the angle between the axis of newly proliferated SMCs and that of the vessel at all observation times (43 +/- 11 deg, 42 +/- 10 deg, and 41 +/- 10 deg for days 10, 20, and 30, respectively), indicating a shift of the SMC orientation from the circumferential toward the longitudinal direction. These results suggested that the major tensile strain might play a role in the regulation of SMC orientation during the development of normal blood vessels as well as during remodeling of vein grafts.
Actins↗
[The importance of mesenteric mechanoreceptors for the reflex innervation of resistance blood vessels capacity blood vessels in the splanchnic area].
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Blood Pressure↗
Induction of pancreatic differentiation by signals from blood vessels.
Blood vessels supply developing organs with metabolic sustenance. Here, we demonstrate a role for blood vessels as a source of developmental signals during pancreatic organogenesis. In vitro experiments with embryonic mouse tissues demonstrate that blood vessel endothelium induces insulin expression in isolated endoderm. Removal of the dorsal aorta in Xenopus laevis embryos results in the failure of insulin expression in vivo. Furthermore, using transgenic mice, we show that ectopic vascularization in the posterior foregut leads to ectopic insulin expression and islet hyperplasia. These results indicate that vessels not only provide metabolic sustenance, but also provide inductive signals for organ development.
Animals↗
Prognostic significance of parenchymal lymphatic vessel and blood vessel invasion in carcinoma of the lung.
In a series of 685 men who had undergone a microscopically curative resection of a carcinoma of the lung admitted to a prospective randomized adjuvant chemotherapy trial, a review of the data relative to the prognostic implication of either parenchymal lymphatic vessel or blood vessel invasion as determined by routine histologic examination was carried out. In the patients without parenchymal lymphatic vessel invasion and without lymph node metastasis, the three year survival rate was 61.0 per cent. In those without lymphatic vessel invasion but with lymph node metastasis, the three year survival rate was 34.5 per cent. In the patients with lymphatic vessel invasion and no lymph node metastasis, the three year survival rate was 41.7 per cent and when lymph node metastasis was present, it was 33.8 per cent. In the patients without blood vessel invasion and with neither lymph node metastasis nor lymphatic vessel invasion, the survival rate was 61.9 per cent at three years. When either or one, or both, of the latter were present, the survival rate was 35.6 per cent. In the patients with blood vessel invasion, the three year survival rate in those without lymph node invasion or lymphatic vessel invasion was 58.0 per cent, and in those with either one or both, the survival rate was 34.9 per cent. It is concluded that parenchymal lymphatic vessel invasion in itself is an indication of a poor prognosis. However, blood vessel invasion when identified by routine histologic examination was found to provide little, if any, additional predictive information.
Blood Vessels↗
Biochemical evidence for cholinergic activity in retinal blood vessels.
Blood vessels from human, cat, pig and bovine retinas were analyzed for their contents of choline acetyltransferase (ChAT) and muscarinic binding sites. ChAT was measured by the synthesis of 3H-acetylcholine in the presence of 3H-acetyl CoA and choline. Muscarinic binding sites were determined by the specific binding of 3H-quinuclidinyl benzylate (3H-QNB). Tissue levels of ChAT varied from 39-850 nmol/g/hr, the lowest values being in human tissues. Muscarinic binding sites were less different (0.5 to 1.8 fmol/mg net weight) among the species studied, being the highest values in human retinal vessels. It appears that retinal blood vessels not only have sites to bind acetylcholine, perhaps to mediate physiologic responses, but might be capable of supplying acetylcholine for local vascular tone control.
Animals↗
Effect of radiographic magnification on image contrast of blood vessels.
Blood vessel phantoms 0.5--4 mm in diameter were radiographed with a 0.1 mm x-ray tube with and without scattering medium. The contrast of the blood vessel images was determined by densitometry. Without scattering medium, magnification did not increase the image contrast for 1 mm or larger vessels. With scattering medium, contrast improved significantly due to the reduction of scattered radiation by the air gap between object and film.
Absorptiometry, Photon↗
Immunohistochemical differentiation between lymphangiographically verified lymphatic vessels and blood vessels.
In order to investigate the antigen profile in human lymphatic vessels when compared with blood vessels, postmortem retrograde lymphangiography was done via the thoracic duct on six patients. Formalin fixed, paraffin embedded tissue was stained immunohistochemically for Factor VIII-Related antigen (F VIII R:Ag), with Ulex Europaeus 1 lectin (UEA-1) and for laminin. The results show that the endothelium of blood vessels and lymphatics at all levels of the lymphatic system react positively following staining for Factor VIII-R:Ag and with UEA-1 lectin. The staining for F VIII R:Ag was generally weaker in the endothelial cells lining lymphatic vessels. Staining for the basement membrane component laminin can be used to distinguish lymphatic capillaries and smaller lymphatic collecting vessels from blood vessels.
Antigens↗
Immunohistochemical differentiation between lymphatic vessels and blood vessels--use of anti-basement membrane antibodies and anti-factor VIII-related antigen.
Several immunohistochemical methods using Factor VIII-Related antigen (FVIIIR:Ag), laminin, Type IV collagen and fibronectin antisera were applied for the purpose of differentiating rat lymphatics from blood vessels by light and electron microscopy. Weibel-Palade bodies (WPB) were demonstrated in both types of vessels by conventional electron microscopy. The immunoreactivity to laminin and Type IV collagen in blood vessels showed a strong, continuous, linear subendothelial staining pattern in contrast to lymphatic vessels in which immunoreactivity was absent or weak in paraffin-embedded sections stained with the indirect immunoperoxidase technique. A positive reaction for fibronectin was observed in all extra-vascular tissue spaces as well as in lymphatics and blood vessels. FVIIIR:Ag and WPB were present in both lymphatic and blood endothelial cells. FVIIIR:Ag antiserum labeled with gold particles was observed only in the vacuoles which were assumed to be identical with WPB as demonstrated by our conventional electron microscopy. We conclude that the immunohistochemical method using laminin and Type IV collagen antisera is a reliable and practical way to differentiate lymphatic vessels from blood vessels by light microscopy.
Animals↗
Cellular mechanics and gene expression in blood vessels.
Blood vessels are permanently subjected to mechanical forces in the form of stretch, encompassing cyclic mechanical strain due to the pulsatile nature of blood flow, and shear stress. Alterations in stretch or shear stress invariably produce transformations in the vessel wall that will aim to accommodate the new conditions and to ultimately restore basal levels of tensile stress and shear stress. Vascular cells are equipped with numerous receptors that allow them to detect and respond to the mechanical forces generated by pressure and shear stress. The cytoskeleton and other structural components have an established role in mechanotransduction, being able to transmit and modulate tension within the cell via focal adhesion sites, integrins, cellular junctions and the extracellular matrix. Beyond the structural modifications incurred, mechanical forces can also initiate complex signal transduction cascades leading to functional changes within the cell. Many intracellular pathways, including the MAP kinase cascade, are activated by flow or stretch and initiate, via sequential phosphorylations, the activation of transcription factors and subsequent gene expression.
Animals↗
[Morphological study on innervation of the cerebrospinal blood vessels. I. Cerebral blood vessels].
The distribution of nerve fibers in the cerebral blood vessels was studied by a catecholamine histofluorescence method, acetylcholinesterase (AChE) staining and immunohistochemistry. The ultrastructure of the terminal boutons in the vessel wall was also studied. In the adventitia of the cerebral artery, green fluorescence aminergic fibers and brownish AChE-positive (probably cholinergic) fibers were observed. In contrast, the cerebral venous system showed no AChE-positive fibers. The highest density of aminergic fibers were found in the dural sinus and the second highest in the internal cerebral vein. Serotonin immunoreactive nerve fibers were found along small intraparenchymal blood vessels such as perforating arteries in the brain stem, and arterioles and venules in the cerebral cortex. Under ultrastructural observation, a serotonin immunoreactive terminal was demonstrated in conjunction with the basement membrane of the capillary.
Acetylcholinesterase↗
Angiotensin binding sites in bovine and human retinal blood vessels.
Blood vessels isolated from bovine and human retinas have sites that specifically bind 3H-angiotensin II (3H-Ag II) with an apparent dissociation constant (Kd) of 14 nM and a capacity of binding (Bmax) of 0.82 pmol/g. The binding sites for 3H-Ag II appear to be influenced by guanine nucleotides (GTP) and cations (Mg2+ and Na+) in a way that resembles angiotensin II receptors in other tissues. The physiologic effect of blood-borne or locally-formed angiotensin II on retinal blood flow remains to be defined.
Angiotensin II↗
[Morphological study on innervation of the cerebrospinal blood vessels. II. Spinal blood vessels].
The distribution patterns of aminergic and cholinergic nerve fibers in the feline spinal blood vessels were studied by means of amine histofluorescence and acetylcholinesterase (AChE) staining. The anterior spinal artery had a dense network of aminergic and AChE-positive (probably cholinergic) nerve fibers. The posterior spinal vein, in contrast, had only aminergic nerve fibers. Intraparenchymal small blood vessels in the spinal cord also had strongly fluorescent (probably peripheral) aminergic nerve fibers. This was quite a characteristic feature in the spinal cord. The distribution pattern and the density of these two sorts of nerve fibers widely varied with the individual segment of the spinal cord. The thoracic spinal cord had the lowest number of these nerve fibers throughout the spinal cord. This fact may give a clue to explain why the thoracic spinal cord is most susceptible to ischemic change.
Acetylcholinesterase↗
[Effect of diets of different isomer composition of fatty acids on the blood vessel wall, blood lipids and platelet aggregation].
It was established in rat experiments that prolonged (4.5 months) use of the diet with a high content of spatial (trans-) and positional isomers of fatty acids exerted an adverse effect on the laboratory animals. They showed the impairment of the hemostasis integrity; namely of the walls of blood vessels (aorta, intraorgan arteries of the heart and kidneys), blood lipids, fatty acid composition and aggregation properties of platelets. The animals developed alterations similar to those occurring with the use of the diets rich in saturated fatty acids. The vessels manifested dystrophic alterations of elasticity and smooth muscle cells, whereas blood an increase in the content of atherogenic lipoproteins associated with a high content of total lipids and cholesterol. The ADP-induced enhancement of platelet aggregation was observed in experiments in vitro.
Animals↗
Neurohumoral control of blood vessel tone. Springfield Blood Vessel Symposium. An international symposium held in honor of Che Su, PhD. Springfield, Ill., April 12-13, 1986. Proceedings.
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Blood Vessels↗
[Lymphatic vessels and blood vessels of the lung and of the bronchial anastomosis after autotransplantation--an experimental study].
Changes of the lymph and blood vessels of the lung and of the bronchus anastomosis were investigated in dogs in several times after 180 autotransplantations of a lobe of the lung. The regeneration of the lymph vessels in the lung autograft started 8-14 days after the operation and was concluded 30-60 days after the operation. Afterwards the lymph vessels had the normal structure and there was no difference to the intact lung. The anatomic regeneration of the lymph vessels in the bronchus anastomosis and the lymph drain from the lung autograft started 8-9 days after the operation and was concluded within the first 14 days. The regeneration of the bronchial arterial system began 6-7 days after the autotransplantation and was completed within the first 14 days.
Animals↗
Cyclic angiogenesis and blood vessel regression in the ovary: blood vessel regression during luteolysis involves endothelial cell detachment and vessel occlusion.
Angiogenesis occurs as a cyclically regulated process in the ovary and the uterus. After ovulation, there is massive sprouting of blood vessels in the growing corpus luteum (CL) during the first third of the ovarian cycle. During luteolysis and for several weeks thereafter, all newly formed vessels regress. Here we have systematically analyzed regression of blood vessels during luteolysis to identify mechanisms of blood vessel regression. Blood vessel counts are highest in the midcycle CL and drop rapidly after the onset of luteolysis. After a rapid phase of tissue dissociation, blood vessel regression proceeds slowly over several weeks in the residual CL. Endothelial cells in regressing vessels acquire a distinctly rounded and condensed phenotype. Ultrastructural analysis of blood vessel regression processes in the cyclic CL suggests two major mechanisms of blood vessel regression: a) detachment of rounded endothelial cells from their basement membrane, leaving areas devoid of covering endothelial cell monolayer, and b) contraction and occlusion of arterioles and small arteries with pronounced proliferation of smooth muscle cells. In situ detection of nucleosomal fragmentation products demonstrates numerous apoptotic luteal cells, but only a few apoptotic endothelial cells in the regressing CL. Induction of apoptosis in cultured endothelial cell monolayers by RGD peptides demonstrated that endothelial cells detach from their adhesive surface before fully becoming positive for nucleosomal fragmentation products. These data indicate that cyclic angiogenic processes in the ovary offer a suitable experimental system to analyze mechanisms of blood vessel growth and regression, and suggest that detachment of endothelial cells before apoptosis as well as contractive occlusion of blood vessels may be critical determinants of blood vessel regression.
Animals↗
Blood vessel invasion in gastric carcinoma.
In an effort to identify factors in primary tumors that would predict liver metastases, we retrospectively reviewed 102 patients with gastric cancer, and their tissue blocks were restained. New staining methods for elastin and endothelium were used to identify intratumoral vessels. Blood vessel invasion, thus detected, was analyzed quantitatively, as well as qualitatively, according to the location of invasion, the size of the involved vessel, and the mode of invasion. The invasion was then compared with the presence of liver metastasis by the chi 2 test, the Mann-Whitney U test, and the Student t test. Discrimination analysis of factors significantly correlated with liver metastasis was performed with linear discrimination function to identify a predictive model for liver metastasis. Significant differences in qualitative frequency of blood vessel invasion (p less than 0.01), the number of lymph node metastases (p less than 0.05), and the depth of tumor invasion (p less than 0.05) were found in those patients in whom liver metastasis developed, as compared with 5-year disease-free survivors. Quantitative analysis of blood vessel invasion revealed eight other factors correlated with liver metastasis; frequency of blood vessel invasion in the 0.01 to 0.1 mm and 0.1 to 1 mm diameter vessels, in the forms of complete, partial tumor thrombi, and vessel wall invasion, in the submucosa and the subserosa, and the number of anatomic stomach layers involved. Application of the discrimination coefficient to these factors allows prediction of liver metastasis with 81.8% sensitivity, 85.3% specificity, and 83.6% accuracy. Liver metastasis can be predicted from the qualitative and quantitative examination of blood vessel invasion within the primary tumor by the use of an elastic fiber stain.
Capillaries↗