Arterial supply of the human long biceps tendon

The present study deals with the question whether an insufficient vascular supply of certain areas can be made responsible for ruptures in the biceps tendon. The macroscopic and microscopic examination shows that the blood supply of the tendon in the part most prone to ruptures, that is in the bicipital groove, is guaranteed even in older individuals. It is at least much better than in the intra-articular portion where ruptures are seldom observed. This means that mechanical components such as friction are dominant. The vascular factors seem to play a minor part.     

A possible balance of magnesium accumulations among bone, cartilage, artery, and vein in single human individuals

It is known that a large quantity of magnesium contains bones, and the magnesium contents in spongy bones decrease gradually with advancing age. To elucidate the relationships between a decrease of mineral contents in human bones and an accumulation of minerals in the other human tissues, the content of magnesium was analyzed by inductively coupled plasma-atomic emission spectrometry among human bones, arteries, veins, and cartilages in 27 subjects (17 men and 10 women). These were resected from the subjects who died in the age range 40–98 yr. Calcanei were chosen for analysis of magnesium contents in contrast with femoral, popliteal, and common carotid arteries, internal jugular and femoral veins, superior and inferior venae cavae, and pubic symphyses. The magnesium contents in the calcanei decreased gradually with aging, whereas they increased progressively in the arteries, veins, and pubic symphyses with aging. It was found that as the magnesium contents decreased in the calcanei, they increased in the arteries, such as the femoral, popliteal, and common carotid arteries, whereas they decreased inversely in the veins, such as the internal jugular and femoral veins and superior and inferior venae cavae. Furthermore, as the magnesium contents decreased in the calcanei, they hardly changed in the pubic symphyses. These suggest that magnesium released from bones is accompanied by accumulation of magnesium in the arteries.     

The origin of the follicular capillaries in the human spleen.

The major arteries which supply the follicular capillaries in the human spleen do not arise as they do in most mammals as lateral or radial branches from the central artery but come from penicillar arteries which penetrate the marginal zone and enter the follicle at various points around its circumference. Such arteries may have a very short course through the red pulp or they may pursue very long courses. Upon entering the follicle, these arteries branch a number of times, the branches remaining together in a tight array of parallel arterioles along with capillaries formed from them, the whole bundle being enveloped by a reticular fiber sheath. There is thus formed an arteriolar-capillary bundle. The whole bundle may branch. From the sides, especially from its central end, arterioles and capillaries radiate out to all parts of the follicle to terminate in the marginal zone or in the follicle itself.     

Pathway of nerves with vasoactive intestinal polypeptide-like immunoreactivity to the major cerebral arteries of the rat

Summary The pathway of nerves with vasoactive intestinal polypeptide(VIP)-like immunoreactivity to the major cerebral arteries was studied in rats by means of the indirect immunofluorescent method. The fibers are densely distributed in the ethmoidal nerves and in the adventitia of both the external and internal ethmoidal arteries. Section of both ethmoidal nerves and external ethmoidal arteries before they enter the cranial cavity induced a marked reduction of VIP-like immunoreactive fibers in the walls of the vessels of the circle of Willis and its major branches. However, section of the external ethmoidal artery alone did not result in visible changes of the nerves around major cerebral arteries. The present study suggests that VIP-like immunoreactive fibers surrounding major cerebral arteries of the rat arise from fibers in the ethmoidal nerve showing immunoreactivity to VIP.     

Anterior spinal arteries. Origin and distribution in man

This study was designed to extend our present knowledge of the origin and distribution of anterior spinal arteries and was carried our using 31 human cadavers with arterial injections of natural latex. The conclusions reached are that there are always one or two anterior spinal arteries (right or left), which proceed from the intracranial segment of the vertebral arteries. These arteries have a descending course, with distribution into the ventral face of the medulla oblongata and the first cervical segments of the medulla spinalis. In cases where there are two anterior spinal arteries, they anastomose with each other to form the common, unpaired and median anterior spinal artery. The different observed locations of the origins of anterior spinal arteries may be systematised into three types. Each of these types has differential characteristics: bilateral origin (type I; 77.4%), unilateral origin (type II; 9.7%) and origin in an intervertebral transversal anastomosis (type III; 12.9%). We do however subdivide the bilateral origin group, according to the calibre of the arteries, into the subtypes 'balanced' (type Ia; 22.6%), 'right dominated' (type Ib; 32.2%) and 'left dominated' (type Ic; 22.6%). The collaterals of the anterior spinal arteries which distribute into the ventral face of the medulla oblongata are described.     

Effects of sodium nitrite on ultraviolet light-induced relaxation and ultraviolet light-dependent activation of guanylate cyclase in bovine mesenteric arteries

It was demonstrated that precontracted strips from different bovine mesenteric arteries showed variation in sensitivity to ultraviolet radiation (366 nm). Some strips relaxed when they were exposed to ultraviolet light, others showed no sensitivity at all and, finally, some showed contraction. However, all arteries relaxed when they were irradiated with UV-light in the presence of 10 microM NaNO2. Ultraviolet radiation (366 nm) increased the activity of guanylate cyclase in crude homogenate from bovine mesenteric arteries by about 20-fold in the presence of NaNO2, while UV-light in the absence of sodium nitrite had no effect on the guanylate cyclase activation. These results support the notion that nitrite may be essential for vascular smooth muscle relaxation by UV-light, possibly through the release of nitric oxide.     

Structural and functional characteristics of the special regulatory devices in the peripheral pulmonary circulation in rabbits

The present study intended to describe in detail the several blood vessels harboring special regulatory devices in rabbit’s pulmonary tissue using light and electron microscopy and immuno-histochemistry. Numerous throttle arteries were recorded within the adventitia of the segmental and sub-segmental bronchi and within pulmonary pleura. These arteries showed characteristic narrow or obliterated lumens and some of them bear longitudinal muscular intimal bolsters. For the first time, TEM revealed some structural modifications of the vascular endothelial cells of these arteries indicating that they become more activated to perform some additional functions. Arteriovenous anastomoses (AVAs) including direct shunt vessels and glomus organs were also recognized. Direct arteriovenous shunts appeared as small connecting devices communicating between small arteries and small veins while glomus organs consisted of the tortuous glomus vessels and the related afferent and efferent vessels. Several arteries and veins showing unique unusual structural characteristics were also described. For the first time, serotonin (5-HT) was strongly expressed in the vascular endothelium and muscle fibers of throttle arteries, in glomus cells of the glomus vessels, and in vascular endothelium of some veins and venules of special structure. The exact role of 5-HT is still unknown and further investigations are required to determine the types and distribution of 5-HT receptors present in these vascular devices. We concluded that these special vascular devices can play a critical role in controlling blood flow and pressure in the peripheral pulmonary circulation; however, the exact physiological mechanisms by which they work or are controlled remain unknown providing a ripe area for further investigation.     

Comparison of calcium accumulation between the arteries of human and monkey

To examine whether an accumulation of elements in the arteries was affected by the way of walking, the authors investigated age-related changes of elements in the arteries of the Japanese, Thai, and Japanese monkeys. After the ordinary dissections by medical students were finished, the subclavian, axillary, brachial, radial, common iliac, externaliliac, femoral, and posterior tibial arteries were resected from the subjects of the Japanese and Thai over 60 yr of age and they were also resected from the Japanese monkeys over 20 yr of age. The element content was determined by inductively coupled plasma-atomic emission spectrometry. It was found that in an comparison between the arteries of anatomically corresponding regions, the average content of Ca was eight times or four times higher in the arteries of the lower limb than in the arteries of the upper limb in the Japanese or Thai, over 60 yr of age, respectively. In the Japanese monkeys over 20 yr of age, the average content of Ca was 1.2 times higher in the arteries of the lower limb than in the arteries of the upper limb. The result suggests that an accumulation of Ca in the arteries of the lower limb with aging is affected by the way of walking.     

The microcirculation of cerebral arteries: a morphologic and morphometric examination of the major canine cerebral arteries

A morphologic and morphometric examination of the major cerebral blood vessels in the dog was carried out to determine whether there were vasa vasorum in these arteries and what features might be associated with them. True vasa vasorum confined to the media were not seen in any of the vessels examined. Microvessels confined to the adventitia, however, were found in the internal carotid and vertebral arteries but not in the basilar, middle cerebral, or anterior spinal arteries. Animal size, vessel size as determined by adventitial and medial area, and the number of smooth muscle cell lamellae were not associated with the presence of these adventitial vessels; they occurred only in arteries with both an intra- and extradural portion. It therefore appears that most canine cerebral arteries do not have vasa vasorum.     

Comparative anatomical study of arteriographs of the hand of primates. Deep palmar arterial arches and their correlating arteries in cercopithecidae, pongidae and hominidae

A three-dimensional angiographic analysis of the deep palmar arterial arches and their correlating arteries in Cercopithecidae, Pongidae and Hominidae revealed the following features. In Cercopithecidae, 3 deep palmar arches are formed by the perforating branches of the 2nd dorsal metacarpal artery: 2 proximal arches (the catella volaris proximalis and the arcus volaris profundus) and 1 distal arch (the catella volaris distalis). The intermetacarpal arteries arise from the catella volaris proximalis and the palmar metacarpal arteries arise from the arcus volaris profundus. In Pongidae, the arches are formed by the perforating branches of the 1st dorsal metacarpal artery, and they are composed of only the catella volaris proximalis and catella volaris distalis. In Hominidae, the arches are formed by the perforating branches of the 1st dorsal metacarpal artery, and they consist of the arcus volaris profundus and an incomplete catella volaris distalis.     

Angiology of the brain of the baboon Papio ursinus, the vervet monkey Cercopithecus pygerithrus, and the bushbaby Galago senegalensis

The investigation was undertaken to compare the blood supply and venous drainage of the brain of the baboon P. ursinus, the vervet monkey C. pygerithrus, and the bushbaby G. senegalensis with that of man, because these animals are extensively used as research models. The blood supply of the three primates was found to be similar in each case. Like man they have a complete circulus arteriosus; but they have a single anterior cerebral artery, whereas man has paired anterior cerebral arteries. The arterial supply to the cerebellum in the primates is similar to that in man, the main difference being a "common inferior cerebellar artery" which bifurcates to form the anterior inferior cerebellar and posterior inferior cerebellar arteries. In man, these arteries arise separately from the basilar artery and vertebral arteries, respectively. The dural venous drainage was also found to be similar in these primates but was far more extensive than in man. The primates have additional sinuses--the more important of these being the "basisphenoid sinus" and the petrosquamous sinus. The former drains the basilar sinus and is itself drained via the vertebral venous plexus and internal jugular vein. The latter drains via the petrosquamous foramen into the retromandibular vein. The petrosquamous sinus has a rostral extension which drains through the foramen ovale and two lateral and medial connecting sinuses which drain the cavernous and basilar sinuses, respectively. These sinuses are not found in man.     

Mass ratios of magnesium to calcium and phosphorus in the arteries of Japanese and Thai

To elucidate quantitative changes of Ca, P, and Mg in the arteries with aging, the authors investigated changes of the mass ratios of Mg to Ca and P in the arteries of Japanese and Thai by inductively coupled plasma-atomic emission spectrometry. The arteries of Japanese that were used were the thoracic and abdominal aortas, coronary, common iliac, internal iliac, external iliac, and femoral arteries, in which very high accumulations of Ca and P occurred in old age. The arteries of Thai that were used were the abdominal aorta, ramifying site of the abdominal aorta, coronary, common iliac, internal iliac, and external iliac arteries. It was found that there were extremely significant correlations both between Ca and Mg contents and between P and Mg contents in all of the arteries of the Japanese and the Thai. With regard to the mass ratio, the mass ratios of Mg to Ca ranged from 1.5% to 2.1% in the six arteries of the Japanese, except for the thoracic aorta at 3.1%, at an advanced stage of atherosclerosis, being similar to each other. In the arteries of the Thai, the mass ratios of Mg to Ca ranged from 1.9% to 3.0%, except for the coronary artery at 0.5%, at an advanced stage of atherosclerosis. The mass ratios of Mg to P ranged from 2.5% to 2.7% in the six arteries of the Japanese, except for the coronary artery at 1.8%, at an advanced stage of atherosclerosis. With regard to the arteries of the Thai, the mass ratios of Mg to P ranged from 1.9% to 3.3%, except for the coronary artery at 0.7%, at an advanced stage of atherosclerosis. These results revealed that both the mass ratios of Mg to Ca and Mg to P were almost similar among the arteries of Japanese and Thai, except for the coronary arteries. Therefore, these results suggested that the inorganic deposits in the coronary arteries of Japanese and Thai were similar to those in the intimal tunica of the thoracic aorta, whereas in the other arteries, they were similar to those in the middle tunica of the thoracic aorta.     

B-mode and color Doppler ultrasound of the forearm arteries in the preoperative screening prior to coronary artery bypass grafting

The objective of this paper was to establish the normal findings of B-mode and color Doppler ultrasound of the forearm arteries in candidates for coronary artery bypass grafting with radial artery graft. Examination of radial and ulnar arteries was performed in 127 patients. The vessel diameters and peak systolic velocities were measured and the presence of atherosclerotic changes, calcifications and anatomical variants was assessed. Radial artery proved to be dominant forearm artery with non-significant side-to-side asymmetry. The luminal changes were present in 30% of the patients. Ulnar arteries were more prone to these changes than radial arteries (28.4% vs. 24.4%). The anatomical variants found included ulnar artery hypoplasia in 3.9% of patients and high brachial artery bifurcation in 2.4% of patients. No cases of high-grade stenosis or occlusion were found. The results of the present study indicate that B-mode and color Doppler are valuable methods for preoperative screening as they enable morphological and functional evaluation of the forearm circulation.     

Effects of recombinant eNOS gene expression on reactivity of small cerebral arteries

Resistance arteries are an important target for vascular gene therapy because they play a key role in the regulation of tissue blood flow. The present study was designed to determine the effects of recombinant endothelial (e) nitric oxide synthase (NOS) gene expression on vasomotor reactivity of small brain stem arteries (internal diameter, 253 +/- 2.5 microm). Arterial rings were exposed ex vivo to an adenoviral vector (10(9) and 10(10) plaque-forming units/ml) encoding eNOS gene or beta-galactosidase gene. Twenty-four hours after transduction, vascular function was examined by isometric force studies. Transgene expression was evident mainly in adventitia. In arteries with endothelium transduced with eNOS gene but not with control beta-galactosidase gene, relaxations to bradykinin and substance P were significantly augmented. Removal of endothelium abolished relaxations to bradykinin and substance P in control and beta-galactosidase arteries. However, in endothelium-denuded arteries transduced with recombinant eNOS, bradykinin and substance P caused relaxations that were abolished in the presence of the NOS inhibitor N(G)-nitro-L-arginine methyl ester. In control arteries, endothelium removal augmented relaxations to the nitric oxide donors sodium nitroprusside and diethylamine NONOate. This augmentation was absent in eNOS gene-transduced arteries without endothelium. Our results suggest that, in small brain stem arteries, expression of recombinant eNOS increases biosynthesis of nitric oxide. Adventitia of small arteries is a good target for expression of recombinant eNOS. Genetically engineered adventitial cells may serve as a substitute source of nitric oxide in cerebral arteries with dysfunctional endothelium.     

Wave propagation in a model of the arterial circulation

The propagation of the arterial pulse wave in the large systemic arteries has been calculated using a linearised method of characteristics analysis to follow the waves generated by the heart. The model includes anatomical and physiological data for the 55 largest arteries adjusted so that the bifurcating tree of arteries is well matched for forward travelling waves. The peripheral arteries in the model are terminated by resistance elements which are adjusted to produce a physiologically reasonable distribution of mean blood flow. In the model, the pressure and velocity wave generated by the contraction of the left ventricle propagates to the periphery where it is reflected. These reflected waves are re-reflected by each of the bifurcations that they encounter and a very complex pattern of waves is generated. The results of the calculations exhibit many of the features of the systemic arteries, including the increase of the pulse pressure with distance away from the heart as well as the initial decrease and then the large increase in the magnitude of back flow during late systole going from the ascending aorta to the abdominal aorta to the arteries of the leg. The model is then used to study the effects of the reflection or absorption of waves by the heart and the mechanisms leading to the incisura are investigated. Calculations are carried out with the total occlusion of different arterial segments in order to model experiments in which the effects of the occlusion of different arteries on pressure and flow in the ascending aorta were measured. Finally, the effects of changes in peripheral resistance on pressure and velocity waveforms are also studied. We conclude from these calculations that the complex pattern of wave propagation in the large arteries may be the most important determinant of arterial haemodynamics.     

Action of agonists and antagonists on adrenergic receptors in isolated porcine coronary arteries

The adrenergic receptors of porcine coronary arteries were investigated in helically cut strips of small (less than or equal to 0.5 mm outer-diameter (od), medium (0.8-1.2 mm od), large (1.5-2.5 mm od), and very large (greater than 4 mm od) coronary arteries. Both the beta1 agonist dobutamine and the beta2 agonist terbutaline relaxed coronary arteries partially contracted by 25 mM of KCl. Dobutamine contracted small coronary arteries at 10(-5) M concentrations, then relaxed them at 10(-4) M. The beta1-adrenoceptor antagonist metoprolol contracted coronary arteries relaxed by either dobutamine or terbutaline, but the beta2 antagonist H35/25 did so only in high and probably nonselective concentrations. Alpha1-adrenoreceptor stimulating concentrations of phenylephrine did not contract any of the arteries. Metoprolol and high concentrations of H35/25 further contracted large coronary arteries partially contracted by 25 mM potassium. These contractions were blocked by verapamil and papaverine but not by atropine, phentolamine, yohimbine, mepyramine, or methysergide. This seems to indicate that beta-adrenergic receptors in porcine coronary arteries are beta1-receptors, or closely resemble beta1-receptors. They differ from many other beta1-receptors, however, in that they are stimulated by terbutaline. Alpha1 adrenoreceptors seem not to be present in these porcine coronary arteries to a significant extent. Metoprolol and high concentrations of H35/25 have a direct contractile effect in large porcine coronary artery that is not mediated by alpha-adrenergic, muscarinic, histaminergic, or serotonergic receptors but requires verapamil-sensitive calcium.     

Comparative anatomical studies of thyroid and thymic arteries: I. Rat (Rattus norvegicus albinus)

The thyroid and thymic arteries were investigated in 50 male and 50 female rats. In more than 70% of the animals, on both sides the cranial thyroid artery forms a common trunk with the ascending pharyngeal artery. The caudal thyroid artery arises not from the deep cervical but from the pericardiacophrenic artery. It may be replaced, however, by a branch of some other artery, such as the brachiocephalic, subclavian, vertebral, or ascending cervical, suggesting a shift of its origin from the internal thoracic artery to the thyrocervical trunk as in man. All the thoracic lobes of the thymus are supplied directly by a thymic branch of the internal thoracic artery or indirectly by a branch of the pericardiacophrenic artery. More than half of the specimens have a cervical thymic lobe of variable size, which is supplied by a branch of the cranial thyroid, external carotid, and/or occipital arteries. Some of these thymic arteries, except those from the external carotid and occipital arteries, reach the thoracic lobe. The thoracic lobes lacking a cervical lobe may be supplied by the thymic branch arising only from the cranial thyroid artery. Other anomalous arteries supplying the thoracic lobe are derived from the superficial cervical and/or the right common carotid arteries. These results show that the thymic arteries of rats are basically similar to those of man, although they display a clear difference in their frequency and origin.     

Comparison of mechanical behavior among the extrapulmonary arteries from rats

Results of comparative tests on pulmonary arteries from untreated Long-Evans rats are presented from three sections of the artery: the trunk, and the right and left main extrapulmonary arteries. Analyses were conducted looking for mechanical differences between the flow (longitudinal) and circumferential directions, between the right and left main arteries, and between each of the mains and the trunk. The mechanical properties of rat pulmonary arteries were obtained with a bubble inflation technique. A flat disk of rat pulmonary artery was constrained at the periphery and inflated, and the geometry of the resulting bubble of material recorded from six different angles. To analyze the data, the area under the stress-strain curve was calculated for each test and orientation. This area, related to the strain-energy density, was calculated at stress equal to 200kPa, for the purpose of statistical comparison. The mean values for the area show that the trunk is less compliant than the main arteries; this difference is supported by histological evidence. When comparing the circumferential and longitudinal properties of the arteries, differences are found for the trunk and left main arteries, but with opposite orientations being more compliant. The mean values for the two orientations for the right main artery are statistically identical. There was indication of significant difference in mechanical properties between the trunk and the main arteries. The left main artery in the circumferential orientation is highly compliant and appears to strongly influence the likelihood that significant differences will exist when included in a statistical population. These data show that each section of the extrapulmonary arterial system should not be expected to behave identically, and they provide the baseline mechanical behavior of the pulmonary artery from normotensive rats.     

Study of arterial patterns of the hand in primates. Deep palmar arterial arches and their correlating arteries in Macaca fuscata

Study of the arterial patterns of the hand in Macaca fuscata, especially those of the deep palmar arterial arches and their correlating arteries, by three-dimensional arteriographic analysis revealed the following: (1) The deep palmar arterial arches are formed by the perforating branches of the 2nd dorsal metacarpal artery, and they are usually composed of two proximal arches (catella volaris proximalis and arcus volaris profundus) and one distal arch (catella volaris distalis). (2) In the 3rd and 4th metacarpal interosseous spaces, the intermetacarpal arteries arise from the catella volaris proximalis, and the arcus volaris profundus has palmar metacarpal arteries which descend along the palmar side of each metacarpal bone. (3) There is a definite regularity in the formation of the intermetacarpal arteries between the catella volaris proximalis and the catella volaris distalis and of the palmar metacarpal arteries between the arcus volaris profundus and the catella volaris distalis.