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At least 19 recordsLinked to original sources
PubMed1978

[Clinical-experimental studies on the behavior of the normal bladder blood vessels and of tumor vessels towards elevated intravesical pressure].

In 17 patients with tumours of the urinary bladder angiographies of the pelvis were carried out and then the angiography was repeated during an increase of the intravesical pressure to 60--120 mm Hg. In the normal, angiographically depictable vessels of the urinary bladder the blood circulation could not be interrupted by increased intravesical pressure. On the other hand, the pathological vessels of the tumours clearly reacted to an increase of the intravesical pressure. In 9 cases the circulation was completely interrupted, in 6 patients nearly all pathological vessels were compressed, and in 2 patients a clear reduction of the vessels visible before was reached. The different behaviour of normal and pathological vessels in our opinion is based on the inferior construction of the walls of the pathological vessels as well as on the lower blood pressure in the vessels of the tumour.

Aged↗
PubMed1979

[Histochemical and ultrastructural studies of the innervation of the lymph-vessel and blood-vessel wall. 1. Adrenergic innervation].

The adrenergic innervation of the lymph vascular wall was studied by means of the Falck fluorescence histochemical tecnique and electron microscopy with Tranzer and Richards' histochemical tecnique. The lymph vessels wall, compared with that of blood vessels, shows very few adrenergic nerve fibers located in the adventitia outside the smooth muscle cells. The possible role of the nervous system in the motor control of the lymph vessels is discussed.

Adrenergic Fibers↗
PubMed1977

[Collateral circulations and new vessels in retinal branch vein occlusions. II. New vessels (author's transl)].

Two types of anastomotic new vessels develop after retinal branch vein occlusions. In a previous article (Arch. Ophtal. (Paris), 1977, 8-9, pp. 507-522) the useful collateral vessels were described in the re-establishment of a better circulation in the territory of the occluded vein. The second part discusses new vessels: they are dangerous and useless. Their pathogenesis poses the problem of the relationship between hypoxia, ischaemia, revascularisation and vasoproliferation. Their prevention and treatment calls for laser photocoagulation of the ischaemic territory.

Argon↗
PubMed1978

[The so-called recanalisation of cotyledonary vessels with endangitis obliterans of placenta vessels (author's transl)].

With a graphic reconstruction on serial sections, performed with placentas which altogether showed so-called recanalisation, it is possible to work out the fact, that the recanalisation is an effect of the paravascular capillary network and with it to clarify the problem of the so-called recanalisation. It is proved, that the paravascular capillaries undertake compensatory hemodynamic functions and this undertaking of function prevents a complete occlusion of the cotyledonary vessels, so that you have to speak of restlumen and restflow but not of recanalisation. The endangitis obliterans of cotyledonary vessels is again unequivocally pointed out by this phenomenon as a intravital process.

Capillaries↗
PubMed1979

[Histochemical and ultrastructural studies of the innervation of the lymph-vessel and blood-vessel wall. II. Cholinergic innervation].

Using the Acetylcholinesterase (AChE) tecnique applied to light and electron microscopy, was observed that the lymph vascular wall shows very few and inconstant AChE-positive fibers. The cholinergic fibers run prevalently longitudinal in the perivascular connective tissue, only brief segments show a loose network. The results are discussed and compared with blood vessels innervation.

Animals↗
PubMed1978

Small vessel vasculitis caused by hepatitis B virus immune complexes. Small vessel vasculitis and HBsAG.

In a comprehensive study of 80 patients with vasculitis, 4 had concurrent hepatitis B virus (HBV) infection. Polyarteritis nodosa was present in 2 and in the other 2, cutaneous vasculitis, presenting clinically as palpable or Henoch-Schönlein purpura. In one of these patients skin biopsies demonstrated granular deposits of IgM, C3, C4, and the hepatitis B surface antigen (HBsAg) and electron-dense deposits of aggregated 20-nm particles resembling HBsAg in postcapillary venules. Evidence for circulating HBsAg-immune complexes included increased serum Clq binding activity, decreased serum complement, and a cryoprecipitate containing both HBsAg and IgM anti-HBs. Aggregated 20-nm particles resembling intact HBsAg were also seen by negative staining electron microscopy of the serum cryoprecipitate. This patient fulfills all the criteria for a specific immune complex vasculitis caused by his immune response to a chronic HBV infection. These findings emphasize that HBV infection may be associated with small vessel vasculitis as well as polyarteritis nodosa, mixed cryoglobulinemia, and glomerulonephritis. A similar immune response to other viral infections may be expressed as palpable (Henoch-Schönlein) purpura also.

Adult↗
PubMed1978

[The vessels of the inner ear (author's transl)].

The inner ear as an example of a highly specialized sensory organ also possesses a highly specialized vascularisation. This represents an impressive example for a reasonable adaption of the terminal blood vessels to a specific function of the organ fulfilling more than only the nutrition. In this paper the microvascular bed of the cochlea is examined using both the injection method of the vessels and the biomicroscopic observation in vivo. The combination of these technics supported by histologic and stereoscan microscopic examinations has made it possible to give an account of the functional morphology of the inner ear vessels. As a detailed structural analysis of the vessels morphology with the help of dyes that fill the whole of the vessels space (i.e. Berlin blue) is not possible, perfusion experiments with silver nitrate were performed on the inner ear. After the perfusion the vessels are cleaned again, the silver however imbibes the intercellular reticular substances and after exposure produces a continous and sharp framework of the endothelium and--when present--muscular cells, thus showing the angioarchitectural contours. There is a very clear division of the cochlear vessels in a three dimensional space: The arterial and venous vessels are vividly separated from one another, forming two systems of microvascular units in the lateral wall and the spiral lamina. Each unit begins with special blood vessel convoluts in the modiolus, consisting of loops of arterioles. They are weakly muscularized whereas no muscle structures are seen elsewhere in the other parts of the inner ear vessels. There are no a.-v. anastomoses or sphinkters at all. The function of the vessel loops in the modiolus is to flatten the pulse wave as well as to regulate the blood flow in the microvascular bed by vasomotion. This was proved by statistical examinations of 1200 measurements of the widths of the vessels at several points of the cochlea in a blind study with and without vasoactive drugs. The terminology of the vessels is not standardized. The nomenclature in this paper has regard to the classification of the vessels, the course and the topographic localisation. Silver staining reveals changes in the form of the endothelium cells from the arterial towards the venous end. While the arteries show a long stretched spinle or lancet like form they change over blunt, oval, triangular or rhomboid forms into polygonal cells with spiked border lines at the venules. All experiments together give an account that the blood supply of the inner ear is in close correlation with the blood supply of the brain and too possesses autoregulative mechanisms, which must be localized in the convoluts at the beginning of every microvascular unit of the cochlear vessels.

Arterioles↗
PubMedDate not supplied

Central nervous control of venous tone. III. Responses of capacitance and resistance vessels of skin to bulbar and hypothalamic stimulation.

Electrical stimulation of 350 points in the bulbar formation of 35 dogs under chloralose anaesthesia demonstrated the presence of sites producing increase or decrease of systemic arterial pressure (SAP) in the same general morphological limits of bulbar pressor and depressor regions as described by earlier authors. Simultaneous recording of pressure changes in the cutaneous vessels however demonstrated that pressure changes in these vessels did not correspond to the pressor or depressor effects of the SAP. Instead, responses were obtained in which pressures in cutaneous capacitance and resistance vessels followed a trend which was opposite in direction and magnitude to that of SAP. Thus there were 30 depressor sites which produce increase in cutaneous vessel pressure and 23 pressor sites which produced a fall in cutaneous vessel pressure. For a marked rise in the SAP, only 62 sites elicited equally marked increase in both capacitance and resistance vessel pressure, while another 52 elicited only a small increase of equivalent magnitude in the capacitance and resistance vessels. Stimulation of 84 points produced dissimilar effects on capacitance and resistance vessels out of which 38 elicited moderate increase in resistance vessel tone with minimal changes in the capacitance vessel tone, while 46 points elicited moderate increase in capacitance vessel tone with only a small increase in the resistance vessel tone. These points were diffusely admixed in the bulbar reticular formation. Effects which were exclusive to the capacitance and resistance vessels of skin, singly or in combination, without affecting the SAP were elicited from 12 points while another 28 points produced marked rise or fall of systemic arterial pressure without affecting the cutaneous vessels. These observations suggest that the neuronal organisation regulating cardiovascular activities at the bulbar level is quite complex having the capacity to generate varying activities in different components of the vascular circuits by differentially altering the discharge of the efferent sympathetic fibres on the one hand, and marked selectivity of action on any particular vascular bed or circulatory component on the other hand. Stimulation of 93 points in the hypothalamus produced similar patterns of response as obtained from medulla oblongata. In addition, stimulation of 6 points in the anterior hypothalamus produced a distinctive response accompanied by dilatation of cutaneous resistance and capacitance vessels with marked increase in respiratory rate and minimal changes in the SAP. This type of response which resembled the physiological response employed for heat loss was not obtained from any stimulation site in the medulla oblongata.

Animals↗
PubMed1979

Measurements of the perivascular PO2 in the vicinity of the pial vessels of the cat.

PO2's in the environment of the pial micro-vessels of the cat were measured using recessed tip oxygen microelectrodes. Measurements were made on the surface of vessels with internal diameters ranging from 200 micrometers to 22 micrometers. Blood oxygen partial pressures were also measured inside these vessels by penetrating the vessels with sharpened electrodes. Both intravascular and extravascular PO2 values decreased progressively from the large arterial vessels down to the small arterioles. The observed values of intravascular PO2 showed a systematic longitudinal decrease from 98.5 +/- 10.7 (SEM) mm Hg in the largest vessels down to 72.6 +/- 3.6 mm Hg in the smallest vessels. In addition to the longitudinal gradient, a transmural gradient was observed across the walls of the microvessels. The difference between blood PO2 and vessel surface PO2 was 27.0 +/- 2.5 mm Hg in the largest vessels and 6.0 +/- 2.2 in the smallest. The mean wall thickness in these groups of vessels were 27.0 +/- 1.5 and 7.5 +/- 0.8 micrometers respectively. Measurements of the minimum tissue PO2 on the exposed surface of the cortex yielded a value of 25.4 +/- 6.6 mm Hg. Systemic arterial partial pressure of oxygen averaged 94.7 +/- 4.7 mm Hg. The data indicate that significant gradients for oxygen exist both longitudinally and radially in association with the pial vessels. The longitudinal gradients represent losses of oxygen from the precapillary vessels. The transmural gradients are apparently the result of both consumption by the microvessel wall and diffusional gradients due to oxygen flux into the extravascular space.

Animals↗
PubMed1976

Vessel caliber and branch-angle of human coronary artery branch-points.

Measurements were made of parent and branch vessel diameters and of the included angles of branch-points from postmortem human coronary arteriograms to determine the usefulness of theoretical equations predicting the relationships between parent and branch vessel caliber and between arterial caliber and branch-angle. The formulas were based on the concept that blood vessel size and arrangement provided for blood flow with minimum energy loss. Size relationships between parent vessel and its branches were determined for 42 left main and 53 other epicardial coronary artery branch-points in hearts with angiographically normal arteries. Left main coronary artery branch-points were studied in 68 hearts with various degrees of angiographically defined coronary artery disease. Measured diameters (D) of parent and branch vessels corresponded well to the theoretical formula: (DParent)3 = (DBranch1)3 + (DBranch2)3....,in angiographically normal coronary arteries. The exponent, on the average, is less with increasing grades of vascular disease for left main coronary artery branch-points. Mean area ratio, the sum of the cross-sectional area of the branches divided by the area of parent vessel, decreased with greater arteriographic disease. Area ratio varies with changes in the relative calibers of branch vessels. Fifty-seven branch-angles were determined by graphic analysis of postmortem biplane coronary arteriograms. No relationship could be found between branch-angle and vessel caliber. The included angle between branches varied from 32 degrees to 124 degrees without respect to relative or absolute vessel calibers. The results of these postmortem measurements on human coronary arteriogram suggest that coronary artery caliber may adjust to minimize energy loss at the branch-point but that branch-angle is determined by other factors. Restudy of arteriograms suggests that branch-angle may be determined by branch vessel destination.

Adaptation, Physiological↗
PubMed1978

Direct evidence that the greater contractility of resistance vessels in spontaneously hypertensive rats is associated with a narrowed lumen, a thickened media, and an increased number of smooth muscle cell layers.

The mechanical and morphological properties of segments of certain precisely defined resistance vessels (approximately 150 micrometer lumen diameter) in the mesenteric bed of spontaneously hypertensive (SHR) and normotensive (WKY) rats have been compared in vitro under carefully controlled conditions and also after fixation. At a given transmural pressure, the relaxed SHR vessels (compared with the WKY vessels) would have had a 16% smaller lumen diameter (P less than 0.01) and a 49% thicker media (P less than 0.005), so that the media volume per unit segment length was 31% greater (P less than 0.05). The smooth muscle cells were arranged circumferentially in about four layers in the SHR vessels and in about three layers in the WKY vessels. The SHR active wall tension in response to potassium was 53% greater (P less than 0.02) and to norepinephrine was 50% greater (P less than 0.01) than for WKY. However, the ED50 values for the norepinephrine dose-response curves were similar (approximately 5 micrometer). Activation with potassium plus norepinephrine gave greater responses in both vessel types, than with either agent alone, but the SHR responses were on average only 19% greater than the WKY (P less than 0.10). However, under these conditions, the SHR vessels would have been able to contract against 45% greater transmural pressures (P less than 0.001) because of their smaller lumen. On maximal activation, the mean force developed by each cell (approximately 3.85 micro N) was the same in both vessel types, even though on average (P = 0.10) the SHR cells had a 21% greater cross-sectional area. The results support the Folkow hypothesis that in genetic hypertension the increased peripheral resistance is associated with structural changes in the resistance vessels.

Animals↗