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The vertebral arteries, as the first branches from the subclavian arteries, normally enter into the transverse foramen of the sixth cervical vertebra in dogs. This case report presents the non‐standard course of the left vertebral artery and unilateral asymmetry of the sixth cervical vertebra in a 14‐year‐old female mixed breed dog. The anomaly was an incidental finding during the preparation of a corrosion cast prepared for educational and scientific purposes. The left sixth cervical vertebra transverse foramen and the ventral lamina were not developed. The left vertebral artery originated normally from the left subclavian artery, but atypically entered into the transverse foramen of the fifth cervical vertebra. On the right side, the anatomical structures of the sixth cervical vertebra and the course of the right vertebral artery were normally developed. To our knowledge, this is the first case of such an anomaly described in a dog. [ABSTRACT FROM AUTHOR]

Exercise is beneficial to brain health, and historically, the advantageous effects of exercise on the brain have been attributed to neuronal plasticity. However, it has also become clear that the brain vascular system also exhibits plasticity in response to exercise. This plasticity occurs in areas involved in movement, such as the motor cortex. This experiment aimed to further characterize the effects of exercise on structural vascular plasticity in the male rat motor cortex, by specifically identifying whether features of angiogenesis, the growth of new capillaries, or changes in vessel diameter were present. Male rats in the exercise group engaged in a 5-week bout of voluntary wheel running, while a second group of rats remained sedentary. After the exercise regimen, vascular corrosion casts, resin replicas of the brain vasculature, were made for all animals and imaged using a scanning electron microscope. Results indicate sprouting angiogenesis was the primary form of structural vascular plasticity detected in the motor cortex under these aerobic exercise parameters. Additionally, exercised rats displayed a slight increase in capillary diameter and expanded endothelial cell nuclei diameters in this region. [ABSTRACT FROM AUTHOR]

Background: Vascular diseases from diabetes typically result in conditions that interfere with the microvascular functions, such as erectile dysfunction (ED) of the penis. It is unrevealed which morphological changes the microvasculature of the penis may result from the treatment and supplementation of curcumin. Objective: This study aims to determine the effects of curcumin, the active compound of turmeric, on penile microvasculature in experimentally induced diabetic rats. Methods: Rat were divided into three groups, control © and diabetic (DM). Diabetic rats supplemented with curcumin (DMC) (200 mg/kg BW). For induction of a diabetic condition, rats were injected with a single intraperitoneal injection of streptozotocin (60 mg/kg BW). A histological study and vascular corrosion casting along with scanning electron microscopy (SEM) were used to determine a morphological change of microvessels in the penis of rats after 8 weeks of experiments. Results: The histological investigations of penile tissue of DM group revealed thickly lined venous sinuses with smooth but sparse muscle layers. Dorsal arteries (DA) and deep dorsal veins (DV) of the penis were present of narrow lumen and showed thickening of collagen fibers at their wall of tunica media. An increasing thickness of collagen fibers was observed. Vascular corrosion casting revealed critically decreased diameters of DM venous sinus in the penis' glans, which were observed as shrunken and partially lacking in the distal area of the glans. The diameter of venous sinuses in corpus cavernosum (CC) of DM rats were dilated and the density of venous sinuses was decreased. Interestingly, the signs of vessel restoration and improvement were presented by increasing diameters and recovering with healthy and nourished DA, DV, venous sinus at the area of the glans, and CC of the penis in DMC groups. Conclusion: The results have shown that the effects of curcumin could improve the destruction of the penile microvasculature in induced diabetic rats by STZ. [ABSTRACT FROM AUTHOR]

Background: Diabetes has a significant impact on the impaired function of the reproductive system in the testis. Objective: The aim of this study was to investigate the effects of curcumin from turmeric on structural changes of testicular tissues and microvasculature in STZ-induced diabetic rats. Methods: Rats were injected with a single dose of streptozotocin (60 mg/kg BW) to induce a diabetic condition. Three days after the injection, rats with a blood sugar level > 250 mg/dl were considered diabetic. Rats were allocated to one of three groups, diabetic (DM), diabetic rats receiving curcumin (DMC) (200 mg/kg BW), and control (C). Testicular tissues were studied eight weeks after the treatment using the histological technique. Testicular microvasculature was examined using the vascular corrosion cast technique under a scanning electron microscope (SEM). Results: The testicular tissue of DM group showed damaged seminiferous tubules, spermatocytes, and spermatids with necrosis and germ cells degeneration. Destruction of testicular arteries and veins in pampiniform plexus were demonstrated. The destroyed capillaries, arterioles, and venules demonstrated stenosis and shrinkage. The vessel diameter in all DM groups decreased. In the DMC group which received curcumin, the appearance of all seminiferous tubules, spermatogenic, and sertoli cell was normal. The reconstruction and restoration of testicular artery, pampiniform plexus, capillary network, arterioles, and venules were clear. As a result of curcumin supplementation, the standard and healthy testis microvasculature was restored. The DMC vessels diameter increased back to a quasi normal condition, particularly at the artery, arteriole, and capillary levels. Conclusions: The results provided evident for effects of curcumin could be associated with recovering and improvement of the testicular tissues and microvasculatures in diabetic condition. [ABSTRACT FROM AUTHOR]

Background: Pigs are frequently used as animal models in experimental medicine. To identify processes of vascular development or regression, vascular elements must be recognised and quantified in a three-dimensional (3D) arrangement. Vascular corrosion casts enable the creation of 3D replicas of vascular trees. The aim of our study was to identify suitable casting media and optimise the protocol for porcine liver vascular corrosion casting.Materials and Methods: Mercox II® (Ladd Research, Williston, Vermont, USA) and Biodur E20® Plus (Biodur Products, Heidelberg, Germany) were tested in 4 porcine livers. The resins (volume approximately 700 mL) were injected via the portal vein. Corrosion casts were examined by macro-computed tomography, micro-computed tomography and scanning electron microscopy.Results: For hepatectomies, the operating protocol was optimised to avoid gas or blood clot embolisation. We present a protocol for porcine liver vascular bed casting based on corrosion specimens prepared using Biodur E20® epoxy resin.Conclusions: Only Biodur E20®Plus appeared to be suitable for high-volume vascular corrosion casting due to its optimal permeability, sufficient processing time and minimum fragility. Biodur E20® Plus is slightly elastic, radio-opaque and alcohol-resistant. These properties make this acrylic resin suitable for not only vascular research but also teaching purposes. [ABSTRACT FROM AUTHOR]

This article presents a study which described the follicular vascular modelling from the luteinizing hormone (LH) surge to ovulation in a pig model, characterized by a long periovulatory window. The analyses were conducted on vascular casts of corroded ovaries in order to identify the spatial relationships of three-dimensional biological structures. Researchers observed that the human gonadotropin (hCG) treatment changes the organization and architecture of follicular blood vessels.

The brain is a vital organ that requires a constant blood supply. Stroke occurs when the blood supply to specific parts of the brain is reduced; diabetes is an autonomous risk factor for stroke. The present study aimed to investigate the potential vascular protective effect of gymnemic acid (GM) by assessing the morphological changes of microvasculature, along with VEGFA and angiopoietin-1 (Ang-1) protein expression in the brains of diabetic rats. Rats were divided into five groups, including control, gymnemic control rats (CGM), rats that were rendered diabetic by single injection of 60 mg/kg streptozotocin (STZ), diabetic rats treated with 400 mg/kg GM (STZ + GM) and diabetic rats treated with 4 mg/kg glibenclamide (GL; STZ + GL). After 8 weeks, brain tissues were collected to examine the three-dimensional morphology of the anterior cerebral arteries by vascular corrosion casting. Western blotting was performed to determine VEGFA and Ang-1 expression. Cerebral arteries, arterioles and capillaries were depicted the diameter, thickness and collagen accumulation of the wall, and the results demonstrated narrow diameters, thickened walls and collagen accumulation in the STZ group. After receiving GM, the histopathological changes were similar to that of the control group. Through vascular corrosion casting and microscopy, signs of vessel restoration and improvement were exhibited by increased diameters, and healthy and nourished arterioles and capillaries following treatment with GM. Furthermore, VEGF expression and Ang-1 secretion decreased in the STZ + GM group compared with STZ rats. The results of the present study revealed that GM treatment decreased blood vessel damage in the brain, suggesting that it may be used as a therapeutic target for the treatment of diabetes. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate the growth of the vasculature in the rat humeral head cartilage after the initial development of the secondary ossification centre until the adult organization. Rats aging from 5 weeks to 12 months were used. Histological observations on humeral heads were implemented with morphometrical analysis. Subsequently, vascular corrosion cast, that permits a three-dimensional observation of the vasculature, were prepared and observed by scanning electron microscopy. In young animals the epiphysis contains thin bone trabeculae and most of the epiphysis is occupied by bone marrow spaces. With age, the bone trabeculae progressively enlarge up to double their thickness. The percentage of bone tissue increases from 33.6 to 58.6% of the entire epiphysis, while the bone marrow spaces tend to increase very little in their mean dimension. Vascular corrosion casts show that the epiphyseal microcirculation is well distinguished from that of the diaphysis, and arises from the vessels present in the capsule and the periosteal networks. In young animals the only capillaries are bone marrow sinusoids and few subchondral capillaries. In adult animals small vessels run between the clusters of sinusoids forming the trabecular circulation. Capillary sprouts from sinusoids are always observed both in the young and adult animals. Thus, in adult rats different proper microcirculatory districts can be distinguished in the epiphysis: (a) the sinusoidal network, that supplies the hematopoiesis of the bone marrow and the adjacent osteogenic tissue; (b) the bone tissue microcirculation, limited to small vessels that supply the metabolism and the remodelling of the bone tissue. The reported microvascular organization and its adaptation to the epiphyseal growth represent the morphological basis for understanding the reciprocal interaction among the different tissues in developing and adult rat epiphysis. [ABSTRACT FROM AUTHOR]

The microangioarchitecture of the thalamus and metathalamus in common tree shrew ( Tupaia glis) was studied using vascular corrosion cast/stereomicroscope and SEM technique. The arterial supply of the thalamus and metathalamus was found to originate from perforating branches of the posterior communicating artery, the posterior cerebral artery, the middle cerebral artery, and the anterior choroidal artery. These perforating arteries gave rise to numerous bipinnate arterioles which in turn, with decreasing vessel diameters, branched into a non-fenestrated capillary bed. Venous blood from the superficial parts of the thalamus and metathalamus was collected into the thalamocollicular vein, whereas venous blood from internal aspects of the thalamus was conveyed to the internal cerebral vein. Some venous blood from the most rostral part of the thalamus flowed into tributaries of the middle cerebral vein before draining into the cavernous sinus. Further, the thalamic and metathalamic vascular arrangement was found to be of centripetal type. In addition, thalamic arterial anastomosis was rarely observed. Thus, obstruction of thalamic blood supply could easily lead to thalamic infraction. [ABSTRACT FROM AUTHOR]

While injuries due to a hypoxic state commonly appear later in both intestinal crypts and basal portion of the villi than in the apical portion, a nonhomogeneous distribution of blood flow in the intestinal mucosa may be supposed. The presence of two different microvascular plexuses inside the mucosa, corresponding to the cryptal plexus and the villous plexus, supports the above hypothesis. This work studies the intestinal microvasculature in shocked versus normal rats. Forty-five rats were divided into four groups to study the histological damage and the microvascular bed by ink injection, fluorescent microsphere infusion, and resin injection for scanning electron microscopy (SEM) of vascular corrosion cast (VCC) observations. An infusion pressure of 100 ± 5 mm Hg was used in control animals, while 30 ± 5 mm Hg infusion pressure was adopted for controls as well as for shocked animals to simulate physiological or shock conditions. Hemorrhagic shock was induced by removing blood and maintaining a mean arterial pressure of 30 ± 5 mm Hg for 45–120 mins. A close connection among the patterns of microvasculature obtained with VCC and ink injection technique can be appreciated. In normal rats the whole microvasculature was visualized, but in both normal and shocked animals injected at low pressure different patterns could be found, generally showing a highly incomplete visualization of the vascular network. A significant decrease of visualization of both the entire microvasculature and the villous plexus is present in shocked animals when compared to unshocked controls, while no difference in the cryptal plexus visualization was observed. These observations suggest that the cryptal plexus is perfused preferentially during hemorrhagic shock, as a consequence of its peculiar microvascular organization. This may explain the relative resistance of the crypts, compared to villi, to hypoxic injuries in order to sustain endocrine function and the regenerative capability of the mucosa after prolonged hypoperfusion conditions that can lead to villous damage and temporary loss of the intestinal barrier function. [ABSTRACT FROM AUTHOR]

Background: Female sexual dysfunction is a common but poorly understood human condition. One of the aspects hindering progress in this area is the lack of appropriate animal models that can be used to study the complex factors involved in this sexual health problem. Recently, attention has focused on the probable role of vascular dynamics of the genital organs and their potential for impact on female sexuality. The objective of this study was to provide a better description of the vascular anatomy of the female rat vagina and external genital organs in an attempt to better develop this as an animal model to study female sexual dysfunction. Methods: Young female (nonestrous) virgin rats were anesthetized, the abdominal aorta was cannulated, and the distal vasculature was flushed and fixed in vivo for histological studies or for subsequent infusion with Mercox resin for vascular corrosion casting. Vascular corrosion casts of the external genitalia (vagina and vulva) were studied using a scanning electron microscope (SEM). Fixed tissue specimens were also embedded and sectioned for histochemical and immunohistochemical analysis. Results: Scanning electron microscopy imaging allowed a description of the vascular and microvascular system of the nonestrous female rat genitalia. Major feeding vessels were located laterally in the muscular and serosal layers of the vagina with a complex system of interanastomosing collaterals between these large lateral trunks. The sub-epithelial region of the vaginal wall contains a dense and rich network of capillaries that perfuse the epithelium. These data were corroborated by two- dimensional histochemistry and immunostaining for endothelial and smooth muscle cells on paraffin-embedded thin sections of the female vagina and vulva. Conclusion: This study provides the first detailed three-dimensional en bloc view of the macro- and microvascular anatomy of the female rat vagina and vulva. The findings suggest an active interaction between the microvasculature and the epithelial cells of the vaginal wall. This study will provide the basic anatomic groundwork for future experiments on perturbations of the vascular system of the rat female genitalia in response to hormonal stimuli and various disease states. [ABSTRACT FROM AUTHOR]

The article discusses a study that investigates the efficacy of electrical stimulation on sequential vascular dynamics during bone regeneration. The researchers create osseous defects in the femur of Wistar rats, in which the other are treated with electric stimulation while the other are not. The study reveals that electrical stimulation provided a change in vascular achitecture that influenced bone formation and healing.

To observe the branching site of the rat gastric submucosal arteriole toward the mucosal capillary network, we used vascular corrosion casting, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), under various conditions, including the normal state, water immersion restraint stress for 24 h, ethanol-induced ulcer and administration of low and high doses of noradrenaline. In normal rats, the branching site of the submucosal arteriole toward the mucosa was slightly narrowed, as seen in the cast observations. The SEM and TEM observations revealed that this narrowing was due to the presence of the so-called 'intra-arterial cushion'. In the restraint stress rats, this narrowing was increased. TEM and direct SEM observation of the intra-arterial cushion showed much the same findings. In the noradrenaline administered rats, similar changes were observed but not so in the rats with an ethanol-induced ulcer. Arterio-venous-anastomoses (AVA) were not observed in the submucosa, under any of the conditions used. We suggest that the submucosal intra-arterial cushions occurring at the branching sites of the submucosal arterioles may play an important role in regulating blood flow to the gastric mucosa. [ABSTRACT FROM AUTHOR]

Splenic vascular casts of the common tree shrew, Tupaia glis, were constructed with Batson's No. 17 plastic mixture and studied with the scanning electron microscope (SEM). Fifteen adult animals of both sexes, weighing between 120 and 180 g were used. Under ether anaesthesia, each animal was injected with 0.05 ml heparin intracardially; the right atrium was cut open and then 250 ml of 0.9% NaCl, followed by 50 ml of 10% neutral formalin, (in four animals) was injected through the left ventricle. Plastic mixture was injected through the same opening. After complete polymerization of the plastic, the spleen and surrounding tissues were removed and macerated in 40% KOH. The air-dried casts were then coated with carbon and gold before viewing and photographing under SEM at 15 kV. It was found that the splenic arteries penetrated deep into the organ before they divided into trabecular arteries and divided again into central arterioles. Each central arteriole sent out 15 to 30 radiating arterioles, called penicillar arterioles, and further divided into smaller vessels entering the marginal zone and red pulp. In this area each arteriole continued directly into either marginal or red pulp sinusoids. The sinusoids emptied into pulp venules which joined to form trabecular veins. Most of the trabecular veins travelled to the cortical area underneath the splenic capsule before approaching the hilum, where they finally drained into splenic and short gastric veins. It is likely that the spleen of the common tree shrew has a closed circulation. [ABSTRACT FROM AUTHOR]

On the diaphysis of the femur in Wistar strain, the blood vascular fine architecture which was supplied in the peripheral region in the bone marrow, was three-dimensionally studied by cast preparation-SEM observation method. Small arteries and precapillary arteries running in the spaces among sinusoidal veins approached to the bone surface. Blood capillaries in continuty from the precapillary arteries formed a single layer of network with various meshes near the bone surface. This network was observed to be communicated directly with the terminal portion of the peripheral sinusoidal veins just underlying the network. These sinusoidal veins collecting coral-like, formed a conical structure showing their constitutional units. [ABSTRACT FROM AUTHOR]

The three dimensional vascular microarchitecture of mercox resin on the lateral surface of parietal bone in Wistar strain adult male rats (b. w. 260-350 g.) was studied in relation to bone formation by SEM observation of corrosion casts. The microarchitecture was a single layer of network composed of precapillary artery, capillary and postcapillary vein, which were serpigious, sometimes joined with the vein from the vascular foramen of bone. The meshes of this network, which were irregular and varied in size, existed apart from the bone surface. According to the report of Iwaku and Ozawa (1986), it was reported that the vascular microarchitecture of the bone surface was very changable during the process of bone remodeling and this network, which was shown on the flat bone surface in this study, was very similar to one in the resting phase and/or the period in which the bone formation further advanced. From these facts and the morphological features of the bone surface observed here by SEM, it is suggested that this vascular network was closely related with the resting stage and/or the period in which bone formation further advanced in bone remodeling. [ABSTRACT FROM AUTHOR]

Injection of certain materials into blood vessels enables three dimensional visualization of vascular architecture and has provided abundant information which is not available by reconstruction of serial sections. By injection methods, the vascular architecture can be visualized either with scanning electron microscopy (SEM) after injection of resin and tissue digestion or with light microscopy (LM) after injection of barium sulfate and tissue clearing. The author has successfully observed whole blood vessels of 13.5-18.5 day mouse embryos using the collodion cast method in SEM. In mouse embryos younger than 12.5 embryonic days, a part, not whole, of blood vessels was obtained using cast colloiding. When the X-ray contrast medium was injected, the whole vasculature of the 9.5 day embryo was elucidated with LM, and the backscattered electron image and the secondary electron image of the identical area in the lung alveolar capillaries of the 17.5 day embryo were obtained with SEM, which showed the spatial relationship between the capillaries and their circumferential cells three dimensionally. Cast and injection methods are reviewed with respect to their application for investigating the development of mouse embryo. [ABSTRACT FROM AUTHOR]

This study was designed to examine the vascular system of human xenotransplanted tumors on nude mice with different complementary morphometrical and morphological methods. The vascular system shows a chaotic arrangement. There is an extreme heterogeneity in the vascular distribution and density. Large avascular regions could be identified in several non-necrotic tumors. There was no clear difference in the vascular density between the center and the periphery of the tumors, nor was there any zonal correlation for the distribution of the necrosis. With three-dimensional corrosion casts it could be demonstrated that clusters of vessels were directly beneath areas almost free of vessels. In the center, vessels often form a sinusoidal system with numerous blind ends without clearly discernible endothelial cells. Numerous irregular tumor-cell-lined sinusoids are visible next to endothelial-lined vessels with transmission electron microscopy. With scanning electron microscopy it could be demonstrated that large-calibre endotheliazed vessels were found in the direct vicinity or in the center of non-viable zones. Even large-calibre vessels have a capillary wall structure. Sometimes, a basement membrane cannot be observed at all or only incompletely. There are numerous indications of vascular discontinuities and leaks with a widespread intercellular occurrence of blood cells. [ABSTRACT FROM AUTHOR]