Structural changes in the small intestine wall and its lymphatic bed after gastrectomy

Morphologically and histochemically structural changes of the small intestine wall and its lymphatic bed have been studied in 104 dogs after the stomach resection. After the operation an increase in the diameter of the lymphatic capillaries and vessels takes place. Lateral dilatations and protrusions in the capillary walls appear, new anastomoses in all the membranes are formed, they are mostly manifested in the mucous membrane. Histopathological rearrangement in the small intestine wall is demonstrated as edema of the mucous membrane, as plethora of the vessels, as lymphoid infiltration and as changes of the villi forms.     

Regrowth of lymphatic vessels following transection of the muscle coat in the rat small intestine

Regeneration of lymphatic vessels after transection of the muscle coat in the rat jejunum was studied by histochemical methods. The lymphatic regrowth occurred behind the regeneration of blood vessels. Enzyme histochemistry for 5-nucleotidase (5-Nase) demonstrated the manner of lymphatic regrowth, which was essentially attributed to vascular sprouting from preexisting lymphatics, and structural changes of the endothelial cells indicating their high migratory potential. The lymphatic regeneration progressively advanced with vascular maturation throughout the experimental period. The expression of 5-Nase in the regenerating lymphatics was increased in proportion to their growth. VEGF-C, a highly specific lymphangiogenic factor, was highly expressed in a subpopulation of interstitial cells, being close to the regrowing lymphatics with immunoreactivity of its receptor, VEGFR-3, in the regenerative area. The present findings suggest that transection of the intestinal muscle coat affords a useful experimental model for the investigation of lymphatic regeneration in tissue repair and that the interstitium may play a crucial role in lymphangiogenesis.     

Penetration of vaccinia virus through the mucosa of the small intestine and its dissemination in the body following enteric immunization of monkeys]

The authors studied the penetration of variolo-vaccine virus through the mucosa of the small intestine of Macacus rhesus in enteral immunization, by immunofluorescent and virological methods. Fifteen minutes after the immunization the variolo-vaccine virus was revealed at the surface of the mucosal prismatic epithelium and in the t. mucosa propria within the cytoplasm of cells of the macrophage type. Dissemination of the process with detection of the variolo-vaccine virus in the blood, the lymph nodes, spleen and liver was determined within the range of 1 to 3 hours.     

The interrelations of the lymphatic capillaries with the nerve structures in the wall of the small intestine]

The character of interrelations of nervous structures and the lymphatic capillary walls has been studied in cats. Under the light microscope twisted nervous fiber terminals of the intestinal neuron dendrites have been revealed around the lymphatic capillaries. Electron microscopical investigation has not revealed any specialized contacts of the nervous terminals and the lymphatic capillary walls. The receptors and terminals of axons do not situate nearer than 10 nm from the latter. According to the structure of synaptic vesicles among the axonal terminals next to the lymphatic capillary walls cholinergic, adrenergic and purinergic ones are described. The influence of the nervous system to the function of the small intestine lymphatic capillaries is mediated via the precapillary space. The neuromediators from the axonal terminals get into it owing to absence of neurolemmocytic membranes around them.     

Lymphatic bed of the muscular sheath of the small intestine in animals and man during ontogenesis]

In the anatomy of the lymphatic bed of the small intestine muscle layer still there are obscure questions on the phylo- and ontogenesis of man and animals. Under study were 92 corpses (35 men, 27 cats and 30 dogs) of different age, beginning from the intrauterine period to old age. Different methods were used: polychromatic injection; macro- and microscopic dissection; staining after van Gieson and with haematoxilineeosin; impregnation with 0,25-1% solution of silver nitrate; dehydration and clearing; counting of the density of loops per a mm2 and the depth of their disposition in the intestinal wall with an ocular-micrometer. It was shown that formation of the lymph capillaries and their network in cats, dogs and man began from the end of the intrauterine period, was completed in new-borns and became sufficiently developed in young age. The structure of the lymph capillary networks is closely connected with the development of the muscle layer of the small intestine. Formation of the lymph lacunas begins after birth. With age the lymph capillary network becomes looser, the loops break and their size enlarges.     

Microtopographic relation between the lymphatic capillaries and glands of the small intestine

Microtopographic interrelationships of the lymphatic capillaries and glands of the small intestine have been investigated taking into account new data on the diffuse endocrine system, which includes endocrine cells of the gastro-intestinal tract. An immediate contact of the lymphatic capillaries with the intestinal glands, resembling microtopographic interrelationships of the lymphatic capillaries in the endocrine glands, has been revealed in total translucent and histological preparations. A suggestion is made that the microtopographic interrelationships of the lymphatic capillaries and the intestinal glands can be regarded as a morphologic basis for absorption of hormones produced by the endocrine cells of the intestinal glands.     

Development of the lymphatic bed of the human esophageal wall]

The lymphatic capillaries are firstly determined in fetuses at the age of 3-4 months in the oesophagus submucous lamina. In fetuses of 5-6 months of age transition of the lymphatic capillaries from the submucous lamina into the mucous membrane proper is noted. In fetuses of 6 months of age perivascular lymphatic capillaries and vessels appear. They form peculiar paths around arterioles, venules, arterial branches and venous tributaries. The lymphatic bed of the oesophageal wall is rather well developed in mature fetuses and newborns. In adult and old persons a partial reduction of the lymphatic bed in the oesophageal wall is observed.     

Hemomicrocirculatory bed in the rabbit small intestine wall during ontogenesis

Hemomicrocirculatory bed has been studied in fragments of the small intestine wall, obtained from 30 rabbits of various age. During ontogenesis the number and caliber of all components of the hemomicrocirculatory bed increase, as well as density of the capillary network in connection with formation and growth of the small intestine membranes. At the age of two or three years involutive changes are observed in the blood bed of this organ.     

Ultrastructure of mesenteric lymphatic postcapillaries of the small intestine of the human fetus

Lymphatic vessels of the small intestine mesentery have been investigated in 36 human fetuses 3-6-month-old. Lymphatic postcapillaries are the predominant link in the lymphomicrocirculatory bed studied. They differ from the capillaries only by presence of valves. Intersegmentary valves and velves at the places where the lymphatic capillaries get into the postcapillaries are described; they are situated along the whole length of the postcapillary. Both types of the valves can be uni- and besinusoid, and according to the number of endotheliocytes, covering the sinuses, uni- and multicellular. Cells of fibroblastic line and developing collagenous fibers are inevitable structural components and situate in their base. Ultrastructural peculiarities of the lymphatic postcapillary wall are described. Structural mechanisms responsible for dilatation and narrowing of the vascular lumen (formation of the pulse wave) are discussed. The data obtained support the conception successively elaborated by V. V. Kuprianov on the lymphatic postcapillary as an inevitable link of the lymphomicrocirculatory bed.     

The blood microcirculatory bed of the small intestine, liver and pancreas after resection of the stomach and small intestine

As demonstrate the experiments performed on dogs and rats, after surgical intervention to the stomach and small intestine, other organs of the digestive system experience an increased functional loading, that results in noticeable changes in the intraorganic blood vessels and the blood microcirculatory bed organs. The course of the compensatory processes occurs with a definite regularity--as stages. The first stage is characterized with a predominance of the pathological reactions over the compensatory ones, in the second stage certain compensatory possibilities of the organism are noted. In the third stage the compensatory-adaptive reactions prevail over the pathological processes in the blood vessels and blood microcirculatory bed.     

Effect of alcoholic intoxication on the lymphatic bed of the heart]

Cardiac lymphatic bed was studied in 120 male corpses at the age of 17--55 years, normal and of those died from alcohol intoxication and from cardiac ischemia. The methods of intratissue injection of coloured masses, impregnation after V. V. Kuprianov, histological and histochemical investigations were applied. Data in figures were obtained by means of a grid for cyto-, histo- and stereometric investigations and by a scanning integrant microspectrophotometer sim-2. Statistical data were obtained by a computer "Mir". It was demonstrated that the cardiac lymphatic system responds in a definite way to alcohol intoxication. Four forms of structural state in the lymphatic bed elements were revealed, specific density of its different components was calculated. A certain connection was noted to occur between morphological changes under the effect of toxic doses of alcohol; there was also a reaction of compensatory-adaptive elements of lymphodynamics. A number of pathological changes in cardiac tissues resulting in heart insufficiency were presented. Peculiarities in poisoning phases were demonstrated morphologically.     

Fat absorption following temporary ischemia of the small intestine

Ischemia of the rat small intestine lasting 40 min leads to pronounced structural disorders in lipid transport across the enterocytes, reduction in enzymatic activity of the cells and in absorption function, and to the loss of fat with feces. The normalization of the indicated parameters occurs at varying times and ends after 1 month. Fat transport abnormality is marked by an increase in lipid drops in the cavities of the smooth endoplasmic network, appearance of large and numerous matrix lipids, by a greater reduction, as compared to normal, in the membranes of the rough endoplasmic network and lamellar complex in the epithelium of the villi. Accumulation of lipids and retardation of their release from the cytoplasm are determined by incomplete differentiation of the epithelium, which is also combined with a decreased enzymatic activity.