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Treatment of true bifurcation stenosis by elective stent implantation in parent vessel and non-stent dilatation of side branch: immediate and follow-up results.

Data of 67 consecutive patients who underwent stent implantation in the parent vessel and non-stent dilatation of the side branch of a true bifurcation stenosis was retrospectively analysed. The mean age was 53.2 +/- 9.7 years, with majority (89.6%) being males. Forty-seven (70.1%) lesions involved the bifurcation of left anterior descending artery and its major diagonal branch. The parent vessel was treated using balloon angioplasty in 50 (74.6%), rotational atherectomy in 15 (22.4%) and directional coronary atherectomy in 2 (3.0%) patients. All the patients subsequently received an intracoronary stent in the parent vessel. Depending upon the treatment strategy for the side branch, the patients were divided into two groups: (1) Percutaneous transluminal coronary angioplasty group, which included 37 patients in whom the side branch was dilated by plain balloon angioplasty, and (2) Debulking group, in which 30 patients underwent debulking of the side branch using rotablation or directional coronary atherectomy. Overall, the procedure was successful in 64 (95.6%) patients. One (1.5%) patient developed non-Q wave myocardial infarction during the hospital stay. There were no Q-wave myocardial infarction, need for emergency coronary artery bypass surgery or death. Clinical follow-up of at least six months was available in all patients with a mean duration of 9.5 +/- 3.2 months. Recurrence of symptoms developed in 19 (28.4%) patients. Fourteen (20.9%) patients required target vessel revascularisation, of which 11 (29.7%) belonged to the percutaneous transluminal coronary angioplasty group and 3 (10.0%) to the debulking group, the difference being statistically significant (p = 0.045). The freedom from target vessel revascularisation was 93.1 and 89.4 percent at 6 and 12 months in the debulking group, compared to 78.4 and 68.9 percent at the same time in the percutaneous transluminal coronary angioplasty group. This study thus demonstrates that percutaneous intervention for true bifurcation stenosis with stent implantation in the parent vessel and non-stent dilatation in the side branch provides favourable immediate and follow-up results. Debulking in comparison to plain balloon angioplasty of the side branch results in further improvement in clinical outcome and need for target vessel revascularisation on follow-up.

Adult↗

[The architecture of the cutaneous blood vessels in scent pigs].

OBJECTIVE: To study the anatomy of cutaneous blood vessels of the scent pig, and to provide an animal model for research in plastic surgery. METHODS: Seven Chinese mini-pigs (scent pigs) were used in the study. RESULTS: 1. The scent pig is small, easy to house, rich in panniculus adiposus. 2. The origin of cutaneous blood vessels is divided into three types: the musculo-cutaneous perforator, the intermuscular septal perforator and the direct cutaneous vessel. There are some differences in distribution, size, and architecture from the characteristics of that of human being. 3. The architecture of cutaneous vessels could be divided into four vascular plexuses: the profound vascular plexus, middle vascular plexus, superficial vascular plexus of the superficial fascia and the subdermal vascular plexus. 4. The density of vessels and vessel plexuses in the neck and trunk is higher than that of the legs. CONCLUSION: In terms of the morphology of cutaneous blood vessels, the scent pig is an ideal animal model for skin flap study.

Animals↗

Plasmin proteolysis of endothelial cell and vessel wall associated tissue factor pathway inhibitor.

Plasmin is an important protease that mediates clot fibrinolysis and vessel wall extracellular matrix proteolysis. Recently, in vitro studies have suggested that plasmin can cleave and inactivate recombinant TFPI, a major inhibitor of TF-mediated coagulation. We hypothesized that such an interaction may occur in vascular cells expressing TFPI, or in the vessel wall, with implications for thrombolysis. In a series of experiments, we examined the effects of plasmin on cell surface and extracellular matrix (ECM) associated TFPI in endothelial cells (EC) in culture and on EC and smooth muscle cells (SMC) in the vessel wall. Plasmin (0.2 microM) decreased cell surface and matrix associated TFPI activity in cultured endothelial cells by 77 +/- 5% and 69 +/- 6% respectively (p < 0.01). Plasminogen, the proenzyme form of plasmin had no such effect on cell surface TFPI or matrix TFPI. Cell surface TFPI antigen measured by fluorescence activated cell sorter (FACS) was also significantly reduced by plasmin. Proteolysis of conditioned medium TFPI was suggested by loss of a approximately 45kD TFPI on Western Blot analysis following plasmin treatment. Plasmin also proteolysed a approximately 45kD TFPI protein in the intact ECM of EC, an effect which was inhibited by preincubation with aprotinin, a plasmin inhibitor. Incubation of similar concentrations of plasmin, with homogenates of normal vessel decreased a approximately 45kD TFPI immunoreactive band on Western blot analysis. Plasmin also decreased surface TFPI activity on frozen sections of normal vessel as measured by an amidolytic assay. Finally, plasmin treatment of atherosclerotic plaque sections caused complete removal of TFPI immunoreactivity associated with luminal EC and intimal SMC, when compared to control treated plaque (n = 3). Together these data suggest that plasmin proteolyses the majority of EC-associated (surface and matrix) TFPI and may remove TFPI from the luminal surface and intima of the vessel wall. TFPI proteolysis in cultured EC was associated with significant reduction in TFPI anticoagulant activity. These data provide evidence that plasmin degradation of TFPI occurs in vascular cells and in the vessel wall and may have implications for re-thrombosis following thrombolysis in vivo.

Animals↗

Tumor angiogenesis modulates leukocyte-vessel wall interactions in vivo by reducing endothelial adhesion molecule expression.

The expression of endothelial cell (EC) adhesion molecules involved in leukocyte-vessel wall interactions is suppressed in malignancies. In the present study, we investigated in vivo the regulation of leukocyte-vessel wall interactions by the presence of a tumor. By means of intravital microscopy, tumor necrosis factor alpha-stimulated leukocyte-vessel wall interactions were studied in ear skin microvessels of nude mice bearing small human LS174T colon carcinomas and in C57Bl/6 mice bearing murine B16F10 melanomas. Leukocyte-vessel wall interactions were studied both within and outside small tumors growing in the ear, and in ear microvessels of mice with a large tumor growing on their flank. Tumor-free mice were used as controls. Compared with values measured at the edge of the ear and in the contralateral ear, leukocyte adhesion was found to be diminished significantly in vessels inside the ear tumor in both mouse models. This reduction disappeared with increasing distance from the tumor. Surprisingly, the level of leukocyte adhesion in ear venules of mice with a large flank tumor was also reduced significantly. Leukocyte rolling, i.e., the step preceding adhesion, was not influenced by the presence of a tumor in nude mice, but was down-regulated in immune-competent C57Bl/6 mice. Treatment of mice bearing a small ear tumor with a humanized antivascular endothelial growth factor antibody prevented the down-regulation of leukocyte-vessel wall interactions inside the tumor vessels compared with the nontreated group. Fluorescence-activated cell sorter analysis showed that isolated tumor ECs have suppressed levels of intercellular adhesion molecule 1 as compared with ECs from normal mouse tissues. In cultured b.END5 cells the tumor necrosis factor alpha-induced up-regulation of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 was reduced in ECs that were preincubated with basic fibroblast growth factor or vascular endothelial growth factor. The current results may have an impact on the effectiveness of clinical immunotherapeutic treatment protocols, because immune effector cells may not be able to enter tumor tissue.

Animals↗

Acute recoil of stents used for the relief of stenotic great vessels in the setting of congenital cardiac disease.

We implanted either large or medium Palmaz stents, or a Palmaz Corinthian stent, in various stenotic vessels, such as the pulmonary arteries, pulmonary veins, aorta, or superior caval vein. Using angiograms, we measured the diameter of the stenotic vessel before or after the implantation, the minimal diameter of the lumen, the minimal diameter of the largest fully expanded balloon used to expand the stent, and the diameter immediately after withdrawal of the balloon. The minimal diameter of the fully expanded balloon, and the minimal diameter of the lumen subsequent to expansion, were 8.2 +/- 2.4, and 7.7 +/- 2.3 mm, giving an absolute recoil of 0.5 +/- 0.4 mm, and a proportional recoil of 7 +/- 4%. There was no significant difference in either the absolute or proportional recoil for any of the stents, or for any of the different stenotic vessels. The proportional recoil correlated linearly with the minimal diameter of the lumen prior to the procedure, and with the ratio of the stenosis to the balloon, while the diameter of the stenotic vessels, the minimal diameter of the largest fully expanded balloon, the proportional stenosis prior to the procedure, and the ratio of the balloon to the diameter of the stenotic vessel, had no significant correlation with proportional recoil. The proportional recoil exceeded more than one-tenth when the minimal diameter of the lumen prior to the dilation was less than 3 mm, or the ratio of the balloon to the stenosis was greater than 3.0. An absolute recoil of around 1 mm is common when a large or medium Palmaz, or a Palmaz Corinthian stent, is implanted in great vessels. Balloons with a diameter of approximately one-tenth greater than that of the adjacent vessel may be needed if the minimal diameter of the lumen is small prior to the procedure.

Acute Disease↗

Blood velocity measurement in human conjunctival vessels.

The bulbar conjunctiva is one of the few areas in which blood flow in the peripheral vasculature can be directly and noninvasively observed in the human. Although extensive literature exists describing morphological changes which correlate with a variety of systemic diseases in this vasculature, little quantitative data is available on hemodynamics in either normal or abnormal states. The hemodynamic data available are primarily subjective assessments of "low flow." Approaches to place the subjective assessment on more quantitative grounds have usually been based on photographic techniques that have intrinsic inadequacies. The objective of the work reported here was to develop a system capable of providing sequential blood velocity data potentially useful for providing quantitative information on blood flow and its change in the microvessels of the human conjunctiva. The method that has evolved uses a standard Zeiss slit-lamp to image a subject's conjunctival vessels by using a 1-inch Newvicon TV camera with an electronic magnification of 2x. The video image is simultaneously recorded on a video tape recorder (VTR) to an overall system magnification of approximately 4 microm/raster line. The data acquisition phase requires approximately 5 minutes of patient time, whereas the actual determination of blood velocity in individual vessels is done offline through a modification of the dual-slit videodensimetric method. Two independently controllable video cursors are placed axially over the vessel image with the VTR in the still-frame mode. For each consecutive video field, the position of two reference points on the vessel and the position of each cursor relative to these and to each other are encoded into a computer to track the moving image caused by normal eye movement. The computer then determines new cursor coordinates to ensure a constant position within the vessel. The electrical signals obtained for each cursor site and for each video field are cross-correlated to yield the average blood velocity over the sampled time interval. The system has been calibrated in vitro from 0.2 to 2.5 mm/sec, evaluated in experimental animals, and used to measure blood velocity (0.3 to 1.5 mm/sec) in human conjunctival venules with diameters ranging from 20 to 50 microm. At this writing, blood velocity has been recorded during a period of about 3 months in the same vessel of several postmyocardial infarction patients. Thus, the method appears suitable for determining sequential changes in small vessel blood flow in patients over extended periods of time.

Journal Article↗

[Surgeries on major vessels in removal of different tumors].

Experience in diagnosis and surgical treatment of 49 patients with tumors of different localization close to their major with main vessels is analyzed. Two variants of tumor - vessel interrelation were seen, patients with iatrogenic vascular lesions were included into a separate group. In 9 patients (group 1) only extravasal compression by the tumor was seen. Most of these tumors were benign. In 15 patients (group 2) reconstructive vascular surgeries were performed because of close interrelation with the tumor or tumor spread into the vessel. Most of these tumors were malignant. Iatrogenic lesions of arteries during surgeries were in 25 patients (group 3). It is demonstrated that duplex sonography permits to diagnose affection of vessels by tumors without invasive procedures. All the patients underwent vascular reconstruction simultaneously with tumor removing. Sceletization of vessels with their decompression was the surgery of choice in benign tumors. In malignant tumors it is recommended to remove the tumor with affected segment of vessel and repair of blood flow. Ligation of vessel may be justified in some cases.

Adult↗

Effects of previously well-developed collateral vessels on left internal mammary artery graft flow after bypass surgery.

Transthoracic Doppler ultrasonography can assess left internal mammary artery patency and flow after coronary artery bypass grafting. We aimed to show, by transthoracic Doppler ultrasonography, the early effects upon left internal mammary artery graft flow of preoperative collateral vessels supplying the left anterior descending artery. Thirty-four consecutive patients undergoing coronary artery bypass were prospectively enrolled: 19 patients with collateral vessels supplying the left anterior descending were compared with 15 patients without collaterals. After bypass, end-diastolic velocity, mean velocity, flow volume, and ejection fraction were significantly greater, and the resistivity index was lower in patients with collateral vessels. The changes in velocities, volume, resistivity index, and pulsatility index were also found to be greater in patients with collateral vessels than in those without collaterals. Collateral vessels were the only factor affecting the changes in end-diastolic volume, mean velocity, flow volume, and resistivity index in multivariate analysis. Three factors affected postoperative left ventricular ejection fraction: collateral vessels, preoperative ejection fraction, and changes in left internal mammary flow volume. We conclude that patients with well-developed collaterals to the left anterior descending have better flow in the left internal mammary graft and more significant improvement in left ventricular function after coronary bypass. The flow volume of the mammary graft and the improvement of ventricular systolic functions after coronary bypass might be presumed with the presence of grade 2 or 3 preoperative collateral vessels.

Adult↗

[Significance of chong vessel theory for climacteric reactions].

OBJECTIVE: To probe clinical application value of the Chong Vessel. METHODS: Analyze characteristics of running of the Chong Vessel based on running and distribution of the Chong Vessel in ancient literatures, and summarize indication rule of the Chong Vessel from the function of the Chong Vessel in the human body and the indications of the Chong Vessel, further probe into relation between the Chong Vessel and function of the human endocrine system. CONCLUSION: Acupuncture-moxibustion therapy can exert the action, which can not be attained by drugs, on the diseases and syndromes induced by endocrine imbalance, such as climacteric syndrome and the diseases and syndromes caused by deficiency of both qi and blood in the aged.

Acupuncture Therapy↗

CT angiographic analysis of carotid artery stenosis: comparison of manual assessment, semiautomatic vessel analysis, and digital subtraction angiography.

BACKGROUND AND PURPOSE: To compare multisection CT angiography (CTA) analyzed with source/maximum intensity projection (MIP) images as well as semiautomated vessel analysis software with intra-arterial digital subtraction angiography (DSA) in detection and grading of carotid artery bifurcation stenosis. METHODS: Consecutive patients with sonography evidence of a marked internal carotid artery stenosis underwent both carotid CTA and DSA (37 patients, 73 vessels). In CTA, the grade of stenosis was determined using axial source and MIP images as well as vessel analysis. The scans were blind-analyzed by 2 neuroradiologists using the NASCET criteria. RESULTS: Correlation of CTA source/MIP images versus DSA estimates of stenosis (R = 0.95) was higher than for the vessel analysis method versus DSA (R = 0.89). Compared with DSA, CTA source/MIP images underestimated high (78.2% versus 86.4%, P < .05) and moderate grades of stenosis (57.3% versus 63.1%, P < .05) to a lesser extent than the vessel analysis method (68.5% versus 83.5% and 51.8% versus 63.1%, P < .05). For a high-grade stenosis, sensitivity and specificity of source/MIP image CTA were 75% and 96%, respectively, whereas for the vessel analysis method, they were 47% and 96%, respectively. For moderate stenosis, the source/MIP image CTA sensitivity and specificity were 88% and 82%, respectively, and for vessel analysis method, 62% and 82%, respectively. CTA detected all 4 occlusions. CONCLUSION: In evaluation of carotid stenosis, CTA provides an adequate, less invasive alternative with a high correlation to conventional DSA, though it tends to underestimate clinically relevant grades of stenosis. Its accuracy is not improved by semiautomated analysis. The data support the use of CTA in confirming carotid occlusion.

Aged↗

Microvascular architecture in a mammary carcinoma: branching patterns and vessel dimensions.

The objective of this work was to introduce a tumor vessel classification scheme and to provide the first quantitative measurements of vessel branching patterns and the related vascular dimensions in a mammary carcinoma. Mammary adenocarcinoma R3230AC tumors, grown in the rat ovarian tissue-isolated tumor preparation, were infused with Batson's No. 17 polymer and maintained at an intravascular pressure of 50 mm Hg during polymerization. Maceration of the tumor in KOH allowed visualization of the vasculature. The vessel branching patterns, lengths, and diameters were measured in four tumors (4-5 g). A centrifugal ordering scheme was devised specifically to account for the unique features of tumor microvascular network topology. The arterial networks revealed two types of branching patterns. One type of arteriolar network exhibited decreasing vessel diameters and lengths with increasing branch order. In a second type of network, the diameter and length of the vessels displayed fluctuations in both variables at higher generations. Avascular and poorly vascularized regions with sparse capillary supply were present in the tumors, but analysis of several capillary networks in vascularized regions revealed a nonplanar meshwork of interconnected vessels. The meshworks were composed of vessels with a mean segment length of 67 microns, a mean diameter of 10 microns, and a mean intercapillary distance of 49 microns. Capillary path lengths ranged from 0.5 to 1.5 mm. Thus, tumor capillary diameter was greater than that in most normal tissues and, in the regions where capillary networks existed, intercapillary spacing was in the normal range. In the venous network, diameters decreased from 650 to 20 microns for the first to ninth order venules. Venule length decreased from 5 to 0.5 mm for first to fourth order but was fairly uniform (less than 500 microns) for higher orders. In conclusion, solid tumor vascular architecture, while exhibiting several features that are similar to those observed in normal tissues, has others that are not commonly seen in normal tissues. These features of the tumor microcirculation may lead to heterogeneous local hematocrits, oxygen tensions, and drug concentrations, thus reducing the efficacy of present day cancer therapies.

Adenocarcinoma↗

[Histochemical study on enzymatic barrier of the newly formed vessels in infarcts].

To investigate the properties of the vessels newly formed in cerebral infarcts, we performed enzyme histochemical study for alkaline phosphatase and gamma-glutamyl transpeptidase that are membrane enzyme of capillary endothelial cells in the brain as well as immunohistochemical study for factor VIII related antigen and laminin. Adult mongolian gerbils were used in the experiment to produce cerebral infarcts. The animals showing clear neurological signs of ischemia after occlusion of the left common carotid artery were selected. Following one hour ischemia blood flow was reperfused and the animals were allowed to grow and sacrificed at predetermined intervals ranging from two days to two years. The stainings for alkaline phosphatase and gamma-glutamyl transpeptidase were performed by Brustone method and Rutenburg method respectively, and those for factor VIII related antigen and laminin by PAP method, in frozen sections. Four days after ischemia, vessels of a slightly large size that were running irregularly with reactivity of factor VIII related antigen and circumscribed by laminin were observed in the marginal zone of the infarcts. These newly formed vessels increased in number during the second and the third week also in the center of the infarcts, and one month after ischemia began to decrease. However, a number of vessels were seen in the infarcts, whose features were comparatively similar to those of normal vessels. These vessels remained as long as for two years. The number of the vessels with alkaline phosphatase and gamma-glutamyl transpeptidase activity did not increase during the first week. They increased later during the second and third week.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗

Origins of the neurovascular bundle: interactions between developing nerves and blood vessels in embryonic chick skin.

Growth cones of nerves and endothelial cells of blood vessels are closely analogous in their migratory behavior, and they are both set a similar task during the early development of a limb. Both must invade the mesenchyme to form ramifying networks of large nerves and vessels. Both systems must densely pervade certain regions of the developing limb, such as muscle rudiments, and both form dense cutaneous plexuses at precisely the same depth beneath the epidermis. Moreover, adult tissues show many examples of neurovascular bundles in which nerves and blood vessels run closely parallel and branch in a correlated fashion, suggesting some interdependence during development. We have examined the interrelationship between developing nerves and blood vessels in chick wing skin because it allows a particularly convenient two-dimensional analysis of the two systems which can be revealed simultaneously in the same preparation by injection of Indian ink combined with silver-staining. We show that nerves do not use blood vessels as pathways along which to crawl, but that there are two other ways in which neurovascular associations arise: in some situations nerves and blood vessels follow the same route because they are responding independently to the same mesenchymal cues; and in some situations nerves induce blood vessels to remodel around them.

Animals↗

The blood circulation inside the spleen. I. The arterial blood vessels general distribution in the rat spleen.

As an attempt to investigate the different pathways followed by the blood into the spleen and to analyse their functional significance, a technique was used mainly based on the intraarterial perfusion of a Prussian blue "solution" added of some chemical mediators and vasoactive substances. Such technique provides results which may be analysed taking into account the effect of the anaesthetic used, that may influence the findings. From the anaesthetic used, the sulfuric ether and the barbital sodium produce vasoconstriction of the white pulp blood vessels, whereas the chlorpromazine-promethazine doesn't have this effect, and so the Prussian blue appears inside these vessels. The vasodilator drugs, such as succinonitrile and papaverine hydrochloride, show a general vasodilator effect on the splenic arterial system. Teh arterial vessels of the white and the red pulp, including those placed at the subcapsular areas, become enlarged; into the white pulp, either the central or the peripheral blood vessel plexus of the lymphatic follicle becomes evident. The latter readily constitutes the perifollicular and the pericolumnar plexus. The blood vessels of this plexus become permeable to the Prussian blue "solution" by the heparin sodium effect, and so the dye particles enter the marginal zone and the splenic sinuses. In addition, from the white pulp arteries arise 2 types of anastomotic arterioles which appear enlarged after succinonitrile treatment: The short anastomotic arterioles that crosses the marginal zone entering the red pulp near the white pulp; the long anastomotic arterioles which enter the red pulp and after a long course end up into or around a collector sinus. The addition of histamine dihydrochloride to the perfusion solutions shows a slight vasodilator effect mainly on the subcapsular penicillar arterioles, including the helicine arterioles. The adrenergic stimulation of the splenic blood vessels induces a generalized arterial constriction, except of the anastomotic arterioles, that becomes open; in such way, the blood pathway follows the course of the anastomotic arterioles and the collector arterioles also become constricted. The adrenergic vasoconstrictor effect is inhibited by the phenoxy-benzamine hydrochloride. The addition of acetylcholine chloride, in the dosage, used, induces a generalized arterial vessel constriction, mainly of the perifollicular plexus. This effect is inhibited by atropine sulfate which, on the other hand, produces evident enlargement of the perifollicular and pericolumnar arterial plexus.

Animals↗

Synthetic atrial natriuretic factor is a specific dilator of noradrenaline and serotonin activated renal resistance vessels.

The action of a synthetic 'atrial natriuretic factor' (sANF) on induced tone in isolated rat renal resistance vessels (lumen diameter about 200 microns) was examined and compared with the effects of sANF on resistance vessels of similar size taken from the cerebral, mesenteric and femoral vasculature. Synthetic ANF caused a relaxation of the renal vessels when these were submaximally activated with noradrenaline or serotonin, but had no effect on the responses of the other vessels to these agonists. In contrast to previous reports concerning rabbit aortic vessels, methylene blue (which is thought to cause inhibition of guanyl cyclase) did not reduce the dilator response to sANF in the renal vessels. The results demonstrate that sANF has a specific relaxing effect on renal resistance vessels, and are consistent with its effect being mediated through specific receptors. The mechanism of this relaxant effect remains unknown.

Animals↗

Developmental and radiological anatomy of the superficial cerebral convexity vessels in the human fetus.

The superficial cerebral vessels on the convex side of the cerebral hemisphere were investigated using 40 brains of aborted human fetuses (ranging from 2 to 7 months of gestational age), injected with radiopaque material either through the arterial or venous system. These brains, particularly their vessels, were studied in detail through stepwise roentgenography in stereo-pairs, photography and careful dissections. Morphological changes of the superficial vessels of the cerebral convexity reflect the developmental alterations of the cerebral structures, particularly those of the opercula and cerebral sulci. Between the gestational ages of 3 and 4 months, the middle cerebral artery and its tributaries run radially on the sylvian fossa and over the convexity. Anastomoses among the peripheral branches of the anterior, middle and posterior cerebral arteries take place on the convex side of the hemisphere. At the ages of 3 and 4 months, the middle cerebral vein and its tributaries are well developed compared with the superior and inferior cerebral (or ascending and descending cortical) veins. The middle cerebral vein and its tributaries rapidly regress from the 5th to 7th month. The superior and inferior cerebral veins, on the other hand, develop rapidly during this period. Owing to the development of the opercula and resultant depression of the insula, after seven months of gestation the middle cerebral artery and its branches, begin to differentiate into the vallecular (related to the sylvian vallecula or fronto-temporal notch), insular (related to the insular cortex), opercular (related to the frontal, parietal and temporal opercula) and convexity segments (related to the convex side of the hemisphere). The anastomotic veins of Trolard and Labbé are also recognizable at this stage. The superficial sylvian vein in the process of formation may also be detected. The configuration of the cerebral vessels on the convex side of the hemisphere is also affected greatly by the development of the cerebral sulci. These cerebral vessels may run along, or dip into the sulci. Since the development of the superficial cerebral vessels is closely related to that of the cerebral mantle, these studies should be correlated to detail with those of developmental alterations of the intraparenchymal vessels (medullary arteries and veins). The latter investigation will be presented in a future communication.

Cerebral Arteries↗

Does smooth muscle cell polyploidy occur in resistance vessels of spontaneously hypertensive rats?

The ploidy of smooth muscle cells (SMCs) enzymatically isolated from the aorta and superior mesenteric artery (elastic arteries), caudal artery (small muscular artery) and the small mesenteric arteries and arterioles (mesenteric resistance vessels) of the spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats at ages 12, 26, 32 and 40 weeks was determined by flow cytometric DNA analysis and Feulgen-DNA photometric measurements. Frequency of polyploid cells in the aorta and superior mesenteric artery of the SHR increased from 4.43 +/- 1.35 and 7.58 +/- 1.69%, respectively, at 12 weeks to 31.26 +/- 3.00 and 14.13 +/- 1.30% at 40 weeks. There was a smaller increase in the percentage of polyploid cells in these two vessels of the WKY from 4.73 +/- 0.74 and 5.82 +/- 0.33%, respectively, at 12 weeks to 10.64 +/- 0.17 and 7.68 +/- 0.64% at 40 weeks. The caudal artery and mesenteric resistance vessels showed no significant increase in the percentage of 4N (tetraploid) cells in the SHR from 12 weeks (6.80 +/- 0.92 and 6.10 +/- 0.75%) to 40 weeks (7.83 +/- 0.67 and 7.57 +/- 0.07%). Similarly, there was no significant change in ploidy in these arteries of the WKY. Hence, while polyploidy of SMCs increases in the aorta and superior mesenteric artery of the rat with increasing age and with duration of hypertension, there is no significant change in the number of polyploid cells in smaller vessels such as the caudal artery or mesenteric resistance vessels. Since it is the resistance vessels that are involved in the development and maintenance of hypertension, polyploidy of SMCs in the blood vessel wall appears to hold little relevance to the etiology of this disease. As well, increased incidence of polyploidy is not directly attributable to increases in blood pressure as the caudal artery has a high systolic pressure in the SHR yet the incidence of polyploid cells in this artery does not differ from that of the WKY.

Aging↗

The changes of enzymatic activity in blood vessel walls of rat brain during extrauterine development. Histophotometric studies.

The investigations of acylohydrolase acylocholine (cholinesterase) enzymatic activity in the brain vessels walls were performed during extrauterine ontogenic development on 3rd, 7th, 14th, 21st, 28th, 40th and 60th days of life and in the 18 months old rats using Koelle method. Objective evaluation of histoenzymatic reaction intensity is rather difficult because of subjective factors and technical problems. Therefore, our estimations were performed by the use of microscopic unit "Morphoquant" produced by CARL ZEISS Jena factory and coupled with a KSR 4100 ROBOTRON computer. The measurements on 50 fields from parietal cortex or callosal corpus were executed using white light. The area of a single measuring field was 4,200 micron2. The results of measurements were expressed as the percentage of the measured field area occupated by blood vessels with positive ChE reaction in their walls. The results indicate that the amount of blood vessels with positive ChE reaction during the whole postnatal development is increasing. In particular, a very intense increase in the amount of vessels with ChE reaction take place between 7th to 14th days of extrauterine life. In the white matter of callosal corpus a very strong increase in the blood vessels amount with positive ChE reaction is visible between 21st and 28th days of life. In the brains of 18 months old rats a decrease in the positive blood vessels amount was noted. When compared to the parietal cortex, this decrease was higher in corpus callosum. From 40th day of life the amount of blood vessels with positive histoenzymatic reaction for ChE was higher in the grey matter than in the white matter.

Animals↗