Age-related characteristics of the organic angioarchitectonics of normal rats and in arterial hypertension

Architectonics of intraorganic arterial vessels in the cervical cortex, heart, kidneys and spleen have been investigated in 40 normotensive and spontaneously hypertensive rats, 6 months and 1 year old. In all the organs studied a direct dependence has been revealed between the degree of changes in the intraorganic arteries and relative content of the arterial vessels in the tissue organs. Functional changes of the arterial vessels in the organs studied observed during the hypertensive phase, transfer into the organic ones, as a result of prolonged adaptation, when the stage of a stable hypertension takes place.     

Age-related characteristics of intraorganic vascular structures of the cerebral cortex, heart, kidneys and spleen in rats in the normal state and in arterial hypertension

The work has been performed on 40 normotensive and spontaneously hypertensive rats at the age of 6 months-1 year. In all the organs studied a direct dependence between the degree of changes in the intraorganic arterial walls and a relative content of the arterial vessels in the organ tissues has been revealed. The functional changes of the arterial bed of the organs mentioned in spontaneously hypertensive rats during hypertensive phase at the stage of stable hypertension, as a result of a prolonged adaptation transform into organic ones.     

Vascular bed of a lymph node and lymphodynamics after leg lengthening by the G. A. Ilizarov method

In the experiments performed on dogs, the right shin has been elongated, lymph movement has been studied in the extremity, as well as in the arteries of the popliteal and medial iliac lymph nodes. The lymph movement rate immediately after fracture decreases 6 times, and during the elongation process it gradually restores with normalization on the 14th day of distraction. The integrity of the arterial bed in the lymph node is not disturbed during the elongation process of the shin. The intraorganic bed of the regional lymph nodes reacts to the shin elongation by increasing diameter of the arteries and the number of the functioning vessels. The changes in the arterial bed demonstrate an acceleration of the blood stream in the lymph nodes under the elongation of the shin. After osteogenesis normalization in the lymph stream takes place.     

Structure of the excretory ducts, intraorganic lymphatic vessels, tissue canals and intercellular space of various organs (data of scanning electron microscopy injection replicas)

Architectonics of the biliary canaliculi and intrahepatic ducts systems, as well as intraorganic urinary pathways in white rats have been investigated by means of scanning electron microscopy of injection replica. Acinar structure of the intralobular part of the biliary bed has been proved. Anastomoses between the biliary canaliculi of the neighbouring lobules have been demonstrated. A useful method for obtaining injection replica of the intraorganic lymphatic vessels is filling of the ductal system of the parenchymatous organs with solid resins (methylmethacrylate+) under a high (nonphysiological) pressure. Casts of periportal and paravenous hepatic lymphatic vessels have been obtained. An ability of methylmethacrylate to replicate intercellular and connective tissue spaces is verified. Casts of the perisinusoid spaces (Disse) are obtained for the first time.     

Age-related characteristics of the stromal-parenchymal relations of the human thymus

In 155 thymuses and in 57 capsules of the organ, distributed according to 12 age groups, beginning from fetuses of 5 months up to 90 years, age transformations of stromal-parenchymatous relations of the human thymus have been studied and quantitatively estimated. During the postnatal ontogenesis the thymic capsule and its intraorganic connective, tissue frame together with the parenchyma undergo certain phase reorganizations, specific for each age period. The greatest development of the thymic connective tissue frame reaches at the age of 1-3 years and during sex maturation period. The thymic lymphoepithelial tissue exists during all age periods. In the thymic adipose body foci of extramedullary lymphopoesis are revealed, beginning from the first mature up to the elderly age.     

Morphofunctional characteristics of the intrinsic arterial vessels of the kidney in healthy subjects and in various cardiovascular diseases

The investigation has been performed in 132 kidneys of corpses of persons at various ages, 96 of them died from some cardiovascular diseases and 36--from mechanical asphyxia. Injection, macro-microscopical, histological, biometrical and variational-statistic methods have been used. The total section areas of the arterial vessels is determined, it characterizes the vascular bed capacity of the renal cortical and medullary parts. At atherosclerosis, hypertension and cardiac ischemia an essential decrease in the vascular bed capacity in the cortical part and its increase in the medullary part of the kidney is observed. An increasing diameter of the juxtamedullary glomeruli is supposed to intensify the juxtamedullary blood stream. The greatest changes in architectonics and capacity of the renal arterial bed is observed at hypertension combined with atherosclerosis, and the least--at a chronic cardiac ischemia.     

Extra- and intraorganic blood channel of the rabbit lumbar vertebrae in health and after cutting the segmentary arteries and veins

Extra- and intraorganic blood bed of the lumbar vertebrae has been investigated by means of the cast method and vital injection of the vessels with Indian ink-gelatin mixture and subsequent serial translucent preparations. Existence of constant topographo-anatomical relations has been stated between the segmentary arteries and veins with the lumbar vertebrae. Peculiarities in spatial organization of the microcirculatory bed have been revealed in different zones of the vertebral body, as well as peculiarity of blood supply of the epiphyseal osseous marginal plate. Topography and localization of changes in the intraorganic vertebral blood bed have been studied under conditions of bilateral crossing of the segmentary vascular fasciculi at the level of one, two and three vertebrae. Compensatory resources of the vertebral column blood bed are discussed, when large extra-organic trunks in the lumbar part are damaged.     

Intraorganic venous bed of the stomach cardia in children during the first 3 years of life

The intraorganic venous bed of the gastric cardial part has been studied in 27 organs, obtained from children corpses of both sex beginning from birth up to three years of life. They died from causes that were not connected with gastric or vascular system pathology. The results of the investigation prove the presence of mucous, submucous, muscular and serous-subserous venous plexuses in the wall of the gastric cardial part in children of the first three years of life. Every membrane of the stomach wall has its specific structure of the venous link in the microcirculatory bed. In the stomach mucous membrane already in a newborn there are complexly built microcirculatory pathways. Age changes are mostly expressed in the venous link of the gastric mucous membrane; this is probably connected with functional activity of the given layer of the organ. The largest venous vessels are situated in the gastric submucous base. By the end of the newborn period and, especially fully, during the successive age periods immune protection of the gastric wall is formed as an accumulation of lymphoid tissue to an antigenic effect of food. In these age groups certain structural mechanisms of blood outflow from the gastric wall appear.     

Condition of the internal arterial and microcirculatory bed of the neck muscles of the dog after simultaneous ligation of the common carotid and vertebral arteries

In 21 mongrel dogs changes in the intraorganic arterial and microcirculatory bed of the cervical muscles have been studied after a simultaneous ligation of the common carotid and vertebral arteries. The most pronounced changes of rearrangement are observed during early periods after the operation (up to two months). The form, size of the arterial loops and direction of the blood stream change in them. On the base of the arterio-arterial anastomoses collateralies are formed, their degree of development is progressing with the increase of the postoperative time. The arteriolo-arteriolar anastomoses in small loops convert into microvascular collateralies that are of importance only during early postoperative stages. The new conditions of hemodynamics at the arteriolar level result in a dependent rearrangement in other links of the microcirculatory bed, where a number of compensatory-adaptive mechanisms are revealed. After the magistral by-pass ways are completely formed, the changes observed disappear and the microcirculatory network acquires the features specific for intact animals.     

Viability of the kidney following autovenoplasty of its artery]

A segment of one of the renal arteries of the dog was substituted for a piece of the femoral vein of the same dog. Along the site of vascular anastomoses the kidney was excluded from general blood circulation. The results of the vessel plastics were not always favourable. Inspite of the independence of anastomoses in the course of operation, the lumen of the substituted piece of the renal artery underwent deformity in a number of experiments, the circulation of the kidney was disturbed, the parenchyma of the organ was injured, a part of renal bodies and tubules were atrophied, intraorganic vessels, especially glomeruli were reconstructed. The alterations were of focal character. In general the structure of the kidney was preserved. In most experiments the substitution of the renal artery for the own vein did not cause any disorders. The wall of the transplanted vein was soon reconstructed--artealized, the renal parenchyma kept normal structure. The success of vascular plastics and the full value of blood circulation was controlled by removing the twin organ. Animals with one kidney lived practically unlimited time without obvious disorders, the content of nitrogen in the blood was normal, no alterations were found in intraorganic vessels and the renal parenchyma.     

The effect of lidocain on the renal function

The evidence supporting a role for direct neurogenic control of renal function was investigated in twenty anaesthetized dogs. Unilateral renal sympathectomy was induced by 0.5 mg/kg/min of lidocain infusion into the left renal artery and the kidney function changes were compared to those observed in the right non infused kidney. The renal parameters were similar in the kidneys during the control periods. 0.5 mg/kg/min of lidocain infusion into the left renal artery resulted in significant reductions of the RBF, GFR, urine and sodium excretion in the left kidney. The intrarenal lidocain infusion induced a small decrease of the arterial blood pressure but this can not explain the changes observed in the left kidney. The modifications of the right kidney function during lidocain infusion were significantly less than those observed in the left kidney. Comparing the measured RBF and the renal blood flow calculated by the CPAH in the left kidney during the lidocain infusion, we have found a marked difference, when the decrease of the calculated RBF was greater. We believe that effects of pharmacological denervation can be best explained by the intrarenal hemodinamically mediated changes. The sympathectomy produces a considerable vasoconstriction in the renal cortical vascular bed, subsequently it decreases the RBF, GFR renal sodium and water excretion. But the lidocain blocks the sympathetic nerves influencing the renal medullary vessels and the renal medullary blood flow increases. These observations are not consistent with the notion that renal nerves are at least partially responsible for the natriuresis accompanying salt loading.     

Echography of the kidney and its calyceal-pelvic complex in comparison with the anatomic and roentgenographic data

Anatomical and echographic data have been compared in 35 mature human kidneys. Ultrasound anatomy of the kidney has been verified. It has been stated that the central part of the renal echogram is occupied by the zone of intensive echosignals, that corresponds not to the calyceal complex, as it had been considered previously, but to the renal sinus. The renal sinus filled with fatty tissue and small arterial and venous vessels, their diameter is below the resolving power of the ultrasound device, is visualized as fused intensive echosignals of an elongated form, when the renal scanning is longitudinal, and as oval or round -- when the scanning is transversal. The calyceal-pelvic complex, filled with liquor, is presented as an anechogenic branching structure, situating within the zone of an increased echogeneity. The echographic picture of the calyceal-pelvic complex is always fragmentary: as small anechogenic areas in the hyperechogenic zone mentioned (the small pelvic calyces), or an excentrically situated anechogenic zone near the hilus renalis (the renal pelvis). In order to make the echographic investigations more accurate, it is necessary to follow certain methodical requirements, anatomical comparisons including.     

Recent insights into the interactions between the baroreflex and the kidneys in hypertension

Recent findings in chronically instrumented animals challenge the classic concept that baroreflexes do not play a role in the chronic regulation of arterial pressure. As alterations in renal excretory function are of paramount importance in the chronic regulation of arterial pressure, several of these recent studies have focused on the long-term interactions between the baroreflex and the kidneys during chronic perturbations in arterial pressure and body fluid volumes. An emerging body of evidence indicates that the baroreflex is chronically activated in several experimental models of hypertension, but in most cases, the duration of these studies has not exceeded 2 wk. Although these studies suggest that the baroreflex may play a compensatory role in attenuating the severity of the hypertension, possibly even in primary hypertension with uncertain causes of sympathetic activation, there has been only limited assessment of the quantitative importance of this interaction in the regulation of arterial pressure. In experimental models of secondary hypertension, baroreflex suppression of renal sympathetic nerve activity is sustained and chronically promotes sodium excretion. This raises the possibility that the renal nerves may be the critical efferent link for baroreceptor-induced suppression of central sympathetic output through which long-term compensatory reductions in arterial pressure are produced. This contention is supported by strong theoretical evidence but must be corroborated by experimental studies. Finally, although it is now clear that pressure-induced increases in baroreflex activity persist for longer periods of time than previously suggested, studies using new tools and novel approaches and extending beyond 2 wk of hypertension are needed to elucidate the true role of the baroreflex in the pathogenesis of clinical hypertension.     

Anatomical notes on the capsular veins of the kidney of the cat

Capsular veins of 36 kidneys in cat (Felis domestica) have been investigated on macroscopical level. There are venous shunts on the superficial renal level which occur in both surfaces (dorsal and ventral) and different pathways of these vessels for comparative diagnosis. The collateral renal circulation may be sufficient to maintain the renal vascularization in stress conditions.     

Age-related dynamics of blood supply and vascular-tissue interrelations in the human pineal body

Thirty-seven pineal bodies have been studied. They have been obtained from persons of both sex at the age of 18 up to 88 years, perished from accidental causes. Specific volumes of the epiphyseal tissues and vascular constructions of all types have been determined in histological preparations. In young age (up to 40-45 years) the volume of the intraorganic epiphyseal vascular bed is greater, and its blood supply is better than in persons of elderly and old age, when the sclerosing process in the organ occurs at the expense of outgrowth of fibrous elements of the connective tissue carcass. During the pineal body involution, the volume of its intraorganic vascular bed decreases essentially. This results in certain disturbances of blood supply and affects functional activity of the organ.     

Blood supply of the main vessels in laboratory rats and rabbits

The vascular bed in 25 rabbits and 25 white rats has been revealed by means of vital injection of Indian ink into the intraorganic vessels, staining of erythrocytes (benzidine reaction) and silver impregnation. In preparations of the aorta, inferior and superior vena cava diameter of the vessels, the wall and middle membrane thickness, amount of elastic membranes have been measured. Ramification of small vessels and capillaries are revealed only in the paravasal tissues, surrounding the aorta and veins. In serial sections it has been stated that at their greatest extent vasa vasorum has no walls and only in places, where the intercostal (or others) vessels get out of the aorta in its middle or external tunics, a limited, as to its spread, network of intramural vessels exists. The morphometrical analysis does not show any regular connection between the vascular diameter, wall thickness, or middle membrane thickness, amount of elastic membranes in it with presence or peculiarities in distribution of the intramural vessels.     

Effect of ventilation on sodium excretion in the anesthetized dog with unilateral renal denervation

We studied if the effect of mechanical ventilation induced to keep arterial blood gas values within normal physiological limits has any influence on renal sodium excretion in anesthetized dogs (n = 17) subjected to acute unilateral renal denervation. Compared to the control and the postcontrol periods, ventilation elevated arterial pO2 from 86 +/- 5 to 96 +/- 5 mmHg and blood pH from 7.37 +/- 0.02 to 7.41 +/- 0.01 while arterial pCO2 was decreased from 38 +/- 2 to 33 +/- 1 mmHg (p less than 0.05 in all cases). Compared to the innervated kidney urine flow, urinary sodium and potassium excretion from the denervated kidney were markedly elevated both during spontaneous respiration and during mechanical ventilation but GFR and cPAH were similar on the two sides. Ventilation decreased sodium excretion by the denervated kidney from 314 +/- 26 to 252 +/- 31 mumols/min/100 g k. w. (p less than 0.05). No other excretory changes were noted either in the innervated or in the denervated kidneys. Difference in sodium excretion between innervated and denervated kidneys was decreased from 209 +/- 19 to 126 +/- 20 mumole/min/100 g k. w. (p less than 0.001), due to the ventilation induced diminution of sodium excretion from the denervated kidney. It is concluded that mechanical ventilation of anesthetized dogs modifies sodium excretion, and this phenomenon can be demonstrated only in the denervated kidney.     

Photooptical and ultrastructural changes in the microcirculatory bed of the kidney after functional vasoconstriction

In experiments on rats it was found that at the early stages (5 to 15 minutes) after vasoconstriction of the kidney caused by adrenaline solution there occurred sharp narrowing of the intraorganic arterial bed lumen, particularly that of the afferent arterioles. Ultrastructural changes in the glomerular renal capillary components observed were morphological expression of the effect of angiospasm and circulatory hypoxia. Residual phenomena of constriction of the renal microcirculatory bed still persisted at later stages--in 3, 7 days. These changes characterized the stage of peculiar mobility and contractile properties of their endothelial cells, caused by spasmogenic disturbances of microcirculation.     

Morphofunctional reorganization of the kidneys in lymphatic outflow disturbance

In 115 Wistar male rats structures and rates of tissue blood flow have been studied in the cortical and medullary renal substance histologically, polarographically (estimation of the volumetric tissue blood flow by hydrogen clearance). Systemic arterial (peritoneal aorta), venous (caudal vena cava) and lymphatic (renal lymph nodes) pressures have been measured, normal and after ligation of the thoracic duct at early (1-3 days), middle (1 month) and late (2-3 months) periods. In 1-3 days edema and dystrophy of the renal parenchyma, decrease of the blood flow rate in the cortical and its increase in the renal medullary substance, as well as a sharp elevation of pressure in the lymph nodes are observed. In 1 month of the experiment together with dystrophy and edema moderate sclerosis, decreasing blood flow rate in the cortical and medullary substance are noted. Increase of the systemic arterial and venous pressure and decreasing pressure in the lymph nodes, as well as a sharp increase of the renal nodes mass are revealed. In 2-3 months of the experiment, together with sclerosis of the renal parenchyma, elevated blood flow rate is observed in the kidneys and decreasing pressure in the lymph nodes up to its initial value takes place.     

Efferent neural apparatus of the thymus gland, spleen and lymph nodes and its reaction to electric stimulation of the posterior hypothalamic field

At a histochemical investigation of the rabbit lymphoid organs innervation certain peculiarities on histotopography of adrenergic and acetylcholinesterase (AChE)-containing nervous elements have been established. At a chronic experiment by means of a dosed repeated bilateral electrostimulation of the posterior hypothalamic field in the organs mentioned, inhibition of the functional activity has been noticed. It is most specific not for the AChE-containing structures, but for the adrenergic ones, localized to some extent in the parenchyma, as well as along the course of the blood vessels and their adventitium. The results are discussed in terms of modulatory influence of the posterior hypothalamic field on trophic and functions of the lymphoid tissue. This influence is realized both humoraly and via the nervous pathways (either directly using certain ways and connections, or indirectly by means of neurogenic tonus of the intraorganic blood vessels regulation).