Effect of ultrasound on the formation of arterial and lymphatic collaterals in the rat pelvic extremities]

Pronounced morphological alterations combined with destruction of muscular tissue make their appearance in intact arterial and lymphatic bed of pelvic extremities in rats after treatment with ultrasound of high intensity. Ultrasound of low intensity failed to cause morphological changes either in the arterial or the lymphatic bed of extremities. A course of exposure of injured arterial and lymphatic bed of rat's pelvic extremities to ultrasound of small intensity considerably accelerated processes of formation of the arterial and lymphatic collaterals.     

Strain-gauge plethysmography in the evaluation of the evolution of deep vein thrombosis of the legs

Previous research has shown that MVO (Maximum Venous Outflow), VR (Venous Reflux), VE (Venous Emptying) and the respiratory waves recording are useful in differentiating occlusion and recanalization in postphlebitic syndrome. In the present work strain-gauge plethysmography was employed to quantitate the venous function after deep venous thrombosis of the legs. The studies were performed in a vascular laboratory with controlled temperature (23 to 25 C); records were obtained by a plethysmograph Parks mod. 270 connected to a Hewlett-Packard multi-channel mod. 7700. 17 patients (12 males, 5 females), mean age 55 years (range 24-75) that presented femoropopliteal thrombophlebitis documented by phlebography at the admission to the hospital were examined. MVO with and without superficial veins occlusion was measured by a mercury in silastic strain-gauge placed circumferentially about the calf. A pneumatic cuff thigh was inflated to 60 mm Hg. VE was measured in patients lying in inclined bed with the lower extremities 100 cm below the heart level compressing the calf with a pneumatic cuff 10 times for 5 seconds; the strain-gauge was placed on the foot level. VR after Valsalva's maneuver and the respiratory waves were recorded by a strain-gauge positioned at the maximum girth about the calf in patients lying on inclinated bed with the lower extremities 50 cm below the heart level. The result are here indicated: (Table: see text) There was differences in the evolution of venous function after deep venous thrombosis of the legs for each patient. Strain-gauge plethysmography may become evaluable non invasive technique in the evaluation of deep venous thrombosis evolution in the legs. The therapeutic assessment of postphlebitic syndrome.     

Mathematical analysis of several parameters of the microcirculatory bed of muscles and muscular organs]

The authors propose a complex mathematical method for analysis of the microcirculatory link of the vascular bed of muscles and muscular organs. On the basis of the data of the amount and diameters of the vessels the method permits calculating the following parameters according to the proposed pattern of the table-report and formulas: 1. the square surface of the cross-section of the vascular bed; 2. the square surface of the exchange or contact with the tissue surface of the vascular bed; 3. the density of the vascular network in percentage; 4. the blood volume in the vascular bed in volumetric units and average data; 5. the blood volume in one vessel on the average; 6. the volume of the tissue fed by one vessel; 7. the volume of blood per a unit of the surface of the vascular wall.     

The influence of muscular contractions on acetylcholine effects on nutritive blood flow in the hindpaw of dog.

In the earlier investigations it was shown that muscular exercise augmented the dilator effects of ACh in the vascular bed of the hind leg of dog. To get a closer insight into this phenonenon the effects of acetylcholine on the nutritive blood flow in contracting skeletal muscle in the dog were studied. It was found that i.a. acetylcholine administration raises the nutritive blood flow in the investigated vascular bed within about 30--36 minutes after muscular contractions. The nutritive blood flow during and following muscular contractions induced by stimuli of varying frequency was also investigated.     

Complications and vascular salvage of free-tissue transfers to the extremities

Complications were examined in 122 free flaps to lower and upper extremities in 104 patients, and vascular salvage was examined in 182 free flaps to lower and upper extremities in 158 patients. All patients were treated by the same surgeon. The overall survival rate of flaps was 96 percent. Complications occurred in 22 percent of the flaps. Complication rates were lower in patients with one free flap than in patients with two. Flaps had more vascular complications than nonvascular. Accompanying skin islands were found to be necessary to monitor vascularized bone transfers in order to avoid flap failure. Flow in the pedicle was reestablished in all flaps, but a higher percentage of flaps with longer ischemic times were lost. Although vascular compromise occurred frequently (15 percent), prompt surgical exploration and reexploration were thought to have greatly increased free-flap survival.     

Effect of cyclo- and lipoxygenase blockade on the development of immunogenic shock

In acute experiments on anesthetized dogs it was shown that simultaneous blockade of cyclo- and lipoxygenase (indomethacin and quercetin) completely prevented the development of hypotensive reaction after immune influence induced by intracoronary injection of anti-cardiac antibodies. The prevention of the development of shock reaction was caused by complete depression of pooling blood reaction in the periphery of the vascular bed with the following limitation of venous return to the heart and sharp drop in the cardiac output. Thus, metabolites of arachidonic acid dilating venous part of the vascular bed are of great importance for the development of immunogenic shock.     

Influence of gravitational overload and hypokinesia on the structure of the vascular bed of the stomach]

Under study were effects of gravitation stresses, total hypokinesia and their combinations on blood vessels of the stomach. The work was carried out in 130 rabbits, 16 of them being used to study the normal structure of the gastric vascular bed. The vascular bed was injected with the Gerota's mass followed by clearing, making histological preparations and roentgenography. The investigation has revealed both quantitative and qualitative changes in the structure of the gastric blood vessels. The maximum endurable stress of the ventro-dorsal direction causes morphological shifts less pronounced than stresses of longitudinal directions. With prolonged terms of hypokinesia (1-12 weeks) morphological changes became more pronounced in all the layers of the stomach. A combination of successive gravitation stresses and hypokinesia during 4-12 weeks aggravated morphological changes which occurred after exposure to isolated above factors. The animals subjected to maximum endurable stresses before and after 4-week hypokinesia developed vascular changes more typical for the effects of gravitation. The pretraining of animals did not give a pronounced positive effect on the changes of the angioarchitectonics of all the gastric layers after a repeated stress following 4-week hypokinesia.     

Changes in size and compliance of the calf after 30 days of simulated microgravity

Increased leg venous compliance may contribute to postflight orthostatic intolerance in astronauts. We reported that leg compliance was inversely related to the size of the muscle compartment. The purpose of this study was to test the hypothesis that reduced muscle compartment after long-duration exposure to microgravity would cause increased leg compliance. Eight men, 31-45 yr old, were measured for vascular compliance of the calf and serial circumferences of the calf before and after 30 days of continuous 6 degrees head-down bed rest. Cross-sectional areas (CSA) of muscle, fat, and bone compartments in the calf were determined before and after bed rest by computed tomography. From before to after bed rest, calculated calf volume (cm3) decreased (P less than 0.05) from 1,682 +/- 83 to 1,516 +/- 76. Calf muscle compartment CSA (cm2) also decreased (P less than 0.05) from 74.2 +/- 3.6 to 70.6 +/- 3.4; calf compliance (ml.100 ml-1.mmHg-1.100) increased (P less than 0.05) from 3.9 +/- .7 to 4.9 +/- .5. The percent change in calf compliance after bed rest was significantly correlated with changes in calf muscle compartment CSA (r = 0.72, P less than 0.05). The increased leg compliance observed after exposure to simulated microgravity can be partially explained by reduced muscle compartment. Countermeasures designed to minimize muscle atrophy in the lower extremities may be effective in ameliorating increased venous compliance and orthostatic intolerance after spaceflight.     

Synthetic human adrenomedullin and ADM15-52 have potent short-lasting vasodilator activity in the pulmonary vascular bed of the cat

Responses to synthetic human adrenomedullin, a novel hypotensive peptide localized in several organ systems, including the lung, and the carboxy terminal 15-52 amino acid fragment of adrenomedullin (ADM15-52) were investigated in the pulmonary vascular bed of the intact-chest cat. Under constant flow conditions when baseline tone in the pulmonary vascular bed was raised to a high steady level, injections of adrenomedullin and ADM15-52 into the perfused lobar artery in doses of 0.1-1 nmol, caused significant doserelated decreases in lobar arterial pressure. Since left atrial pressure was unchanged, the decreases in lobar arterial pressure reflect decreases in pulmonary lobar vascular resistance. Adrenomedullin and ADM15-52 exhibited similar vasodilator activity and were approximately 3-fold more potent than bradykinin in the pulmonary vascular bed of the cat. Pulmonary vasodilator responses to adrenomedullin and ADM15-52 were rapid in onset and laster for 150–200 sec, depending on the dose of the peptide injected. The present results demonstrate that synthetic human adrenomedullin and ADM15-52 possess potent, short-lasting vasodilator activity in the pulmonary vascular bed of the cat and suggest that amino acids 15-52 in the peptide are important for the expression of vasodilator activity in the pulmonary vascular bed of the cat.     

Vascular adaptation to deconditioning and the effect of an exercise countermeasure: results of the Berlin Bed Rest study.

Deconditioning is a risk factor for cardiovascular disease. The physiology of vascular adaptation to deconditioning has not been elucidated. The purpose of the present study was to assess the effects of bed rest deconditioning on vascular dimension and function of leg conduit arteries. In addition, the effectiveness of resistive vibration exercise as a countermeasure for vascular deconditioning during bed rest was evaluated. Sixteen healthy men were randomly assigned to bed rest (BR-Ctrl) or to bed rest with resistive vibration exercise (BR-RVE). Before and after 25 and 52 days of strict horizontal bed rest, arterial diameter, blood flow, flow-mediated dilatation (FMD), and nitroglycerin-mediated dilatation were measured by echo Doppler ultrasound. In the BR-Ctrl group, the diameter of the common femoral artery decreased by 13 +/- 3% after 25 and 17 +/- 1% after 52 days of bed rest (P < 0.001). In the BR-RVE group this decrease in diameter was significantly attenuated (5 +/- 2% after 25 days and 6 +/- 2% after 52 days, P < 0.01 vs. BR-Ctrl). Baseline blood flow did not change after bed rest in either group. After 52 days of bed rest, FMD and nitroglycerin-mediated dilatation of the superficial femoral artery were increased in both groups, possibly by increased nitric oxide sensitivity. In conclusion, bed rest deconditioning is accompanied by a reduction in the diameter of the conduit arteries and by an increased reactivity to nitric oxide. Resistive vibration exercise effectively attenuates the diameter decrease of leg conduit arteries after bed rest.     

Elimination of stress-induced activation of DNA reparative synthesis in the myocardium by increasing the load on the heart

The rate of DNA reparative synthesis was studied in the nucleus of myocardial cells in the heart compensatory hyperfunction (HCH) induced by the aorta coarctation and in animals exposed to surgical stress without the aorta coarctation. It was established that both surgery and emotional painful stress activated the DNA reparative synthesis in myocardial cells. For example, 12-24 hrs following the surgery the DNA reparation rate exceeded control values by 50-74%. HCH induced no changes in the DNA reparation rate in nuclei of myocardial cells. The mechanism of stress-induced DNA damage is discussed and a hypothesis is put forward on stabilizing the effect of hyperfunction on the DNA structure.     

Correlations of intracellular and cellular regeneration of the epithelium of the kidney tubules in necronephrosis

The study of radioautographs in ultrathin and semithin sections extracted from animal tissues and following the impulsive as well as long-term injection of 3H-thymidine was made. Intracellular regeneration processes (external cell membrane synthesis, DNA reparation, restoration of the lost albumin-synthesizing complex and cytoskeleton) turned to develop in proximal canals of epithelial cells. The processes were aimed at the liquidation of distortions preventing cell from entering mitosis.     

Effects of 13, 14-dehydroprostacyclin methyl ester on the feline intestinal vascular bed.

The effects of a stable PGI2 analog, 13, 14-dehydro-PGI2 methyl ester and several vasoactive hormones were compared in the feline intestinal vascular bed under conditions of controlled blood flow so that changes in perfusion pressure directly reflect changes in vascular resistance. The PGI2 analog decreased perfusion pressure in a dose-dependent fashion when injected in the range of dose of 0.03-3 microgram and was quite similar to PGE2 whereas isoproterenol was somewhat more potent as a vasodilagor in the feline intestinal vascular bed. The present data show that 13, 14-dehydro-PGI2 methyl ester has potent vasodilator activity in the intestinal vascular bed.     

Vasoconstrictor effects of leukotrienes C4 and D4 in the feline mesenteric vascular bed

The effects of leukotriene C4 (LTC4) and leukotriene D4 (LTD4) in the feline mesenteric vascular bed were investigated under conditions of controlled blood flow so that changes in perfusion pressure directly reflect changes in vascular resistance. Intra-arterial injections of LTC4 and LTD4 (0.3-3.0 micrograms) increased perfusion pressure in a dose-related fashion. Vasoconstrictor responses to LTC 4 and LTD4 were similar to norepinephrine (NE) whereas mesenteric vasoconstrictor response to the thromboxane analog, U46619, was markedly greater than were responses to LTC4 and LTD4. Meclofenamate in a dose that greatly attenuated the systemic depressor response to arachidonic acid was without effect on vasoconstrictor responses to LTC4 and LTD4, NE and U46619 in the mesenteric vascular bed. The present data show that LTC4 and LTD4 possess significant vasoconstrictor activity in the feline mesenteric vascular bed. In addition, the present data suggest that products of the cyclooxygenase pathway do not mediate vasoconstrictor responses to LTC4 and LTD4 in the intestinal circulation of the cat.     

Structure and development of the microcirculatory bed of the pleural villi in man and animals

The structure of the microcirculatory bed in the pleural villi was studied by the method of impregnation with silver nitrate, after V.V. Kuprianov. In human and animal mediastinal pleura, the microcirculatory ways are regulated within polymerously repeated complexes--moduli. A characteristic feature of the pleural villi blood supply is the presence of capillary glomeruli with a vascular peduncle consisting of an arteriole and a venule. Four types of structure are revealed in the vascular peduncle consisting of an arteriole and a venule. Four types of structure are revealed in the vascular peduncle of the pleural villi. They were studied morphometrically. Correlation in the development of the villi microcirculatory bed and that of the vascular peduncle was stated. Participation of villous vessels in the regulation of fluid balance in the pleural cavity was discussed.     

Characteristics of mutagenesis and repair following UV irradiation in the methylotrophic bacterium Pseudomonas methanolica

The methylotrophic bacterium Pseudomonas methanolica was shown to be very resistant to the bactericidal and mutagenic action of UV irradiation. The activity of reparation processes after UV irradiation was also detected as well as a weak photoreactivating activity in P. methanolica. The decrease in the survival rate of irradiated cells under the action of caffeine and acriflavine, reparation inhibitors, is indicative of the activity of the excision reparation systems and, possibly, the recombination branch of postreplicative reparation. No activity of the inducible reparation system was found. It has been concluded that the elevated resistance of P. methanolica cells to the bactericidal and mutagenic action of short-wavelength UV irradiation is associated with the activity of the reparation systems.     

Functional and morphological characteristics of the digestive reaction of gastric mucosa

Morphological state of connective tissue (stromal) cells of the stomach mucous membrane has been studied in healthy persons, having a habitual regime of feeding. During digestive period in the stomach mucous membrane, certain changes develop, which are considered as a digestive reaction. Three stages of the digestive reaction, having strict morphological signs are determined, their connections being stated by means of morphometry and mathematical analysis. I stage (preparatory) is characterized with a moderate vascular reaction, degranulation of mast cells under the superficial++ epithelium of the mucous membrane, with a moderate neutrophilic leukopedesis and a moderate lymphocytic infiltration; II stage (developed) is distinguished as a definitely demonstrated reaction of the microcirculatory bed, intensive degranulation of mast cells at all levels of the mucous membrane, massive discharge of neutrophilic granulocytes and lymphocytes into stroma; III stage (restorative) is characterized with a predominance of fibroblasts and fibrocytes, with reparation of mast cells, with decreasing saturation of stroma with neutrophilic granulocytes, lymphocytes, an increased number of eosinophilic granulocytes takes place. The data obtained widen our knowledge on functional morphology of the stomach mucous membrane, normal and at gastroduodenal pathology.     

Endothelin produces pulmonary vasoconstriction and systemic vasodilation

Endothelin is a newly described polypeptide derived from endothelial cells. The effects of porcine endothelin on the pulmonary vascular bed and systemic vascular bed were investigated in the anesthetized, intact-chest cat under conditions of constant pulmonary blood flow and left atrial pressure. Intralobar bolus injections of porcine endothelin (100-1000 ng) produced a mild vasoconstrictor response in the pulmonary vascular bed. The pulmonary vasoconstrictor response to endothelin was not altered when pulmonary vasomotor tone was increased by infusion of U46619. In contrast to this mild pulmonary vasoconstrictor response, endothelin decreased systemic arterial pressure. Moreover, injections of porcine endothelin into the right and left atria produced similar reductions in aortic pressure as well as similar increases in cardiac output and decreases in systemic vascular resistance. The systemic vasodilator response to porcine endothelin was not affected by beta 2-adrenoceptor blockade. The present data suggest that endothelin does not undergo significant first-pass pulmonary metabolism. The pulmonary vasoconstrictor response to bolus injections of porcine endothelin is not altered by changes in pulmonary vasomotor tone. In contrast, endothelin markedly dilated the systemic vascular bed independently of activation of beta 2-adrenoceptors. The present study provides the first report of the activity of endothelin on pulmonary and systemic hemodynamics in vivo. Moreover, the potent vasodilator activity of endothelin in the systemic vascular bed and its weak effect on pulmonary vessels suggest that endothelin may be more important in the regulation of peripheral vasomotor tone than the pulmonary vascular bed.     

Pulmonary vasodilator responses to vasoactive intestinal peptide in the cat

We investigated the effects of vasoactive intestinal peptide (VIP) in the feline pulmonary vascular bed under conditions of controlled pulmonary blood flow when pulmonary vascular tone was at base-line levels and when vascular resistance was elevated. Under base-line conditions, VIP caused small but significant reductions in lobar arterial pressure without affecting left atrial pressure. Decreases in lobar arterial pressure in response to VIP were greater and were dose related when lobar vascular resistance was increased by intralobar infusion of U 46619, a stable prostaglandin endoperoxide analogue. Acetylcholine and isoproterenol also caused significant decreases in lobar arterial pressure under base-line conditions, and responses to these agents were enhanced when lobar vascular tone was elevated. Moreover, when doses of these agents are expressed in nanomoles, acetylcholine and isoproterenol were more potent than VIP in decreasing lobar arterial pressure. Responses to VIP were longer in duration with a slower onset than were responses to acetylcholine or isoproterenol. Pulmonary vasodilator responses to VIP were unchanged by indomethacin, atropine, or propranolol. The present data demonstrate that VIP has vasodilator activity in the pulmonary vascular bed and that responses are dependent on the existing level of vasoconstrictor tone. These studies indicate that this peptide is less potent than acetylcholine or isoproterenol in dilating the feline pulmonary vascular bed and that responses to VIP are not dependent on a muscarinic or beta-adrenergic mechanism or release of a dilator prostaglandin.     

Evidence for increased protein synthesis in myocardial microvessels after chronic sympathectomy in the dog

Using histochemical methods, evidence of increased protein synthesis was observed in microvessels (diameter less than 100 micrometers) from dog hearts which had been sympathectomized 2 weeks earlier when compared to controls. Such evidence consisted of increased staining intensity for the enzyme glucose-6-phosphate dehydrogenase and for the nucleic acids RNA and DNA. Increases in reaction intensities were noted in approximately 30% of the microvessels examined from the sympathectomized hearts, and may imply a vascular proliferation in these hearts. However, since no increase in capillary density was observed in sympathectomized hearts, a vascular proliferation, if it occurred, may have been involved in development of the coronary collateral circulation. These data support previous results indicating that collateral resistances are reduced following chronic cardiac sympathectomy while resistance of the coronary vascular bed itself is not altered.