Morphologic changes in the microcirculatory bed at stages of prolonged experimental fasting in animals

In 40 white male rats with body mass 180-200 g, by means of silver nitrate impregnation, morphological changes have been studied in the blood microcirculatory bed of the small intestine mesentery, spinal trapezoid muscle and eye ball conjunctiva at various stages of a prolonged fasting. With an increasing time of the experiment, a gradual undirected character of the changes in the microvessels is noted. After 3 days of fasting the changes in diameters of the microvessels, comparing to the control ones, have not any significant values in all the organs studied. After 6 days of fasting significant changes in diameters in all the links of the microcirculatory bed of the eye ball conjunctiva and in that of the spinal trapezoid muscle are observed. The microvascular changes are mostly pronounced on the 9th day of fasting. The maximal decrease of the microvessel diameters is noted in the eye ball conjunctiva, and the minimal--in the small intestine mesentery. The changes in the spinal trapezoid muscle are of intermediate character. The highest points of the structural lability gradient fall on the capillary and postcapillary-venular links of the blood microcirculatory bed.     

Characteristics of endocrine disorders in the early stages of the development of chronic experimental pancreatitis

The experiments on normal mongrel dogs and those with chronic experimental pancreatitis were performed to reveal the early changes of the endocrine pancreas function. The concentration of immunoreactive insulin and glucagon were studied in afferent vessels of the organ after intraarterial glucose-loading during pancreatic perfusion in situ. The data obtained have shown that in chronic pancreatitis the maximum secretion of insulin is decreased and delayed, as compared to normal animals. At the same time insulin-glucagon secretion ratio remains unchanged. That was indicative of the normal alpha-cell function at the early stages of the disease.     

Index of microcirculatory changes in experimental dehydration in animals

On the basis of morphokinetic synthesis principles the method of determination of summarizing criterion of microcirculatory system changes was developed. It consists of marked characteristics of changes of a number of the most important morphofunctional phenomena of each of this system compartments -- interstitial, lymphatic, blood and cellular -- with their successive summation to obtain the systemic microcirculation index. The experimental dehydration in rats being a model has shown that systemic microcirculatory index was 2 times as large in 3 days of dehydration, more than 3 times -- in 6 days, and 4, 5 times -- in 12 days. In the initial stage of the experiments maximal changes were found in interstitial compartment of the microcirculatory system. The intermediate period of dehydration differed by predominant changes of vascular compartment when the lymphatic phenomena were more evident than the hemomicrocirculatory ones. In the later stage of dehydration the cellular component changes of tissues and organs were predominant.     

Mechanisms of disorders in blood rheological properties following prolonged clinical death from acute blood loss

The changes in blood viscosity were studied in 22 anesthetized dogs 10 minutes after clinical death because of acute blood loss. The increased blood viscosity within 3 hours after resuscitation was mainly connected with the appearance and progressive increase of changed red cell quantity.     

Use of chromogenic substrates in the clarification of disorders in the early stages of blood coagulation

The kallikrein specific chromogenic peptide substrates S-2302 (KABI) and Chromozym PK (Boehringer) were used in the first analysis of a familial defect in the early stage of clotting. Slight to extensive prolongation of the activated partial thromboplastin time was seen in the affected persons. Using dextransulfate for activation of plasma marked deficiency in kallikrein activity was found in 3 persons. Using factor XIIa (activated Hageman factor) for activation normal prekallikrein levels were found in 2 of them whereas factor XII levels, however, were below normal. The third had a prekallikrein deficiency presumably caused by oral contraceptives. In a fourth member of the family factor XII deficiency was found with normal kallikrein activity. The application of chromogenic peptide substrates for analysing the early stage of clotting has to take into account the special mechanisms of activation.     

Ultrastructural changes in rat liver in early stages of experimental acute pancreatitis]

Morphologic disorders in the liver during the acute pancreatitis are an important aspect of multiorgan disturbances seen in this disease. The study aimed at evaluating ultrastructural disorders in the of the experimental pancreatitis. The study involved 24 male Wistar rats. The acute experimental pancreatitis has been produced by the injection of a 5% sodium taurocholate during sterile laparotomy. Samples for examination have been taken after 1, 3, 6, and 12 hours. Collected samples have been examined systematically. Mitochondrial pleomorphism, partial RER degranulation, decrease in glycogen content, and autophagocytosis have been noted already within 1 and 3 hours. The degree of these disorders has increased within 6 hours, reaching its peak after 12 hours. Marked degeneration of mitochondria, high autophagocytosis, nearly complete disappearance of glycogen, impaired sinusal endothelium, and Kupffer's cells stimulation, in which increased phagocytic activity has been noted made a complete picture of the ultrastructural disorders. Such morphologic changes in the liver have indicated its damage in the early stages of the acute pancreatitis. It may be of importance for the development of multiorgan complications of this disease.     

Systemic and organic changes in the microcirculatory bed in experimental dehydration of the body

Among systemic mechanisms of microvascular reactivity of the musculus spinotrapezius, pancreas and small intestine mesentery at dehydration, a special role play the changes directed to maintenance of harmony between the capacity of the blood bed and volume of the circulatory blood, morpho-functional factors on regulation of hemodynamics, as well as mechanism of liquor resource++ elimination from the blood bed. The organic peculiarities of the microvascular reactivity at dehydration are determined by topic and quantitative character of their changes.     

Effect of naloxone on blood microcirculatory changes in anaphylactic shock

During the experiment conducted upon 85 guinea-pigs it has been found that the injection of naloxone at the dose of 0.5 g/kg half an hour before the reproduction of anaphylactic shock (AS) by the use of horse serum increases the number of cases of the retarded development of pathological reaction and survival of the animals. Except for the quantitative differences mentioned any peculiarities characterizing the effect of naloxone were not found. As to the morphological differences of variants in the course of AS they are distinctly defined only at the analysis of film preparations of the intestinal mesentery. The typical AS becomes apparent by haemorrhages, by dilatation of all the vessels of blood circulation and by forming of erythrocytic aggregates in them. At the retarded development of AS a spasm of precapillaries is observed. After convalescence of the animals the aggregates of erythrocytes can be revealed only in venules. Studying the animals recovered after AS one can find that for a long time these animals had the erythrocytic aggregates in the clearances of venules, as well as the signs of new formation of the capillaries.     

Function of the microcirculatory system during the long-term regression of the early stages of atherogenesis

Lipid metabolism, intestinal mesentery microcirculatory bed (MCB) and erythrocyte (E) morphology in arterial and venous blood were studied in rabbits with experimental atherosclerosis (the model of N. N. Anichkov) and its spontaneous regression. The interrelation was determined between lipid metabolism (LM), MCB structural and functional disorders and anomalous E form appearance, and to a lesser extent the atheromatosis of the aorta. Microcirculatory (MC) disorders disappeared 12 months later in the regression of the early stages of atherogenesis (after 2 months of diet). The generalized character of MC disorders in LM suggests the existence of a trend towards MC reconstitution in prolonged regression in different organs and tissues. Thus, LM correction at the early stages of the pathological process can be accompanied by the disappearance of MC disorders, which seems important for the prevention of atherosclerosis.     

Patterns in the development of the ultrastructure of elements of the microcirculatory system in the early stages of human embryogenesis

By means of transmissive electron microscopy methods, general regularities in development of the microcirculatory system have been studied at early stages of the human prenatal ontogenesis in functionally different organs. Ultrastructure of two cell types has been described in the mesenchyme of human embryos. Formation mechanisms of the primary blood vessels belonging to the protocapillary type are revealed. Structural peculiarities of the primary protocapillary network differentiating into various links of the secondary organospecific hemomicrocirculatory bed are distinguished. Certain stageness in development of the microcirculatory system is stated, its blood circulatory compartment including. Two stages are determined in development of the microcirculatory system: prevascular and vascular microcirculation. The latter includes the precirculatory and circulatory phases.     

Dynamics of the heart minute volume and rheological properties of the blood in the early post-resuscitation period after preagonal and agonal conditions

Fifteen experiments on heparinized (500 IU/kg) dogs (both male and female) under slight nembutal anaesthesia with promedol have revealed that polyglucin hemodilution (60% of blood; 40% of polyglucin) during resuscitation following 4 hours of hypovolemic hypotension prevented the onset of ischemic hyperperfusion syndrome for 5 minutes of post-resuscitation period. Moreover, delayed hyperperfusion syndrome was not observed 3 hours after resuscitation, as it was in animals with blood reinfusion only. Hyperperfusion syndrome was more expressed in animals, recovered after a 4-hour hypovolemic hypotension, than in animals whose agony was caused by a 2-hour arterial hypotension. The correlation was established between high blood viscosity and post-ischemic hyperperfusion (reactive hyperemia).     

Morphofunctional characteristics of the duodenum in the early stages of experimental escherichiosis

Using the model of experimental colibacillosis in mice morphological, immunomorphological and morphometrical studies of duodenum 1 to 24 hours after inoculation were performed. Typical dynamics of cellular composition in the intestinal wall, accompanied with increased lymphoplasmacellular infiltration, and dystrophic changes in cells of submucosal and intermuscular neuroplexuses were found. The data obtained testify, that the infectious process at the acute state of experimental colibacillosis has an immune character (immediate hypersensitivity of local type), characterised by increasing in immunoglobulin-containing cells and including in this process of mast and endocrine cells.     

Surprisingly high correlation between early and late stages in non-two-state protein folding

We collected quantitative kinetic data on early and late stages of folding in non-two-state proteins from the literature, and studied the relationship between the kinetics of the two stages. There was a surprisingly high correlation between the rate constants of these stages. The correlation coefficient of the logarithmic rate constants was as high as 0.97, which could not be caused by chance. We also studied relationships of the logarithmic rate constants of the two stages with native three-dimensional structures represented by the residue-residue contact map. There were again surprisingly high correlations between the logarithmic rate constants and the number of non-local contact clusters obtained from the contact maps. Because the number of non-local contact clusters represents overall arrangement of substructures in a native protein, the results strongly suggested the importance of the arrangement of the substructures for the kinetics of both early and late stages of protein folding.