[Homeostatic role of calcitonin antibodies in calcium metabolism in experimental diabetes mellitus]. / Gomeostaticheskaia rol' antitel k kal'tsitoninu v obmene kal'tsiia pri éksperimental'nom sakharnom diabete.

In experimental alloxan diabetes marked hypocalcemia and hyperglycemia are observed in the blood of rats during the acute period of the disease (from 1.5 to 2 months). After 2.5-3.5 months of diabetes calcium level reaches the upper normal limit. Simultaneously, antibodies to calcitonin appear. It is quite likely that excessive calcitonin secretion, leading to hypocalcemia, decreased insulin secretion and hyperglycemia take place in the acute stage of diabetes. When diabetes persists the antibodies to calcitonin which reveal a homeostatic reaction blocking the excess of calcitonin appear. This normalizes the level of calcium in the blood and prevents the further increase in the blood sugar level.

[Function of the adrenal medullary layer in rats with experimental alloxan diabetes]. / Funktsional'noe sostoianie mozgovogo sloia nadpochechnikov u krys s éksperimental'nym alloksanovym sakharnym diabetom.

The level of catecholamines in the adrenals and catecholamine synthesis during incubation of adrenal slices in the presence of L-tyrosine were investigated in rats with alloxan diabetes mellitus. Experiments were conducted in 2 groups of rats with experimental diabetes mellitus: intact animals and those subjected to immobilization for 1 h. The results were compared with those of the investigation of 2 similar groups of control animals. In experimental alloxan diabetes the concentration of adrenaline in the adrenals was lowered. An increase in the adrenaline level in the incubation medium was noted in the control group of rats subjected to immobilization, and in the group of intact diabetic animals. No significant rise of adrenaline secretion was observed in diabetic animals subjected to immobilization.

[Calcitonin antibodies in experimental diabetes mellitus]. / Antitela k kal'tsitoninu pri éksperimental'nom sakharnom diabete.

Antibodies to calcitonin appear in blood of rats with experimental alloxan diabetes. This phenomenon is observed only under high blood sugar. At the stage of latent diabetes, i.e. during alloxan administration to the body and low blood sugar no antibodies to calcitonin are detected. It is possible that appearance of autoantibodies to calcitonin is one of pathogenetic factors of hyperglycemia development in rats with alloxan diabetes.

[Deleterious action of adrenaline on the endothelial lining of the vessels]. / Pvrezhdaiushchee deistvie adrenalina na éndotelial'nyi pokrov sosudov.

Perfusion of the aorta of anesthesized rabbits with medium 199 containing adrenaline at a concentration of 10(-6)-10(-4) M results in multiple morphological damages of the endothelial lining: contraction of endotheliocytes with the dilation of intercellular borders, appearance of areas of swelling (from a diffuse edema of single cells up to massive swelling of several hundred cells). The surface of the deendothelized aorta was greater at the highest dose of adrenaline. Inclusion into the perfusate of adrenaline blockers, such as phentolamine and propranolol at a concentration of 10(-5) M prevented endothelial constriction and edema. Similar focal swelling in the intima of aorta and coronary arteries was found in children dying from grave stress (trauma, asphyxia). The data obtained indicate that adrenaline after its therapeutic intravenous or local use may exert a direct damaging effect on the vascular endothelium.

[Heterogeneity of human aortic and arterial endothelium: quantitative study using scanning electron microscopy]. / Geterogennost' éndoteliia aorty i arterii cheloveka: kolichestvennoe izuchenie s pomoshch'iu rastrovoi élektronnoi mikroskopii.

Endothelial lining of the aorta and iliac artery of children under 7 years of age is a homogeneous layer covered with small and medium-sized cells. Large and giant endotheliocytes can only be seen in lipid streaks. In adults with marked atherosclerosis aged 40-75 years, the surface of aortal and arterial lumen is a heterogeneous monolayer covered with polymorphous cells. In lipid streaks and on plaques large and giant endotheliocytes account for 25-41% of total cell population, with giant cells covering up to 50% of the plaque surface. It is suggested that monolayer areas of low and very low density, covered with large and giant cells, can be morphologic markers of arterial involvement in the atheromatous process.

[Quantitative analysis of the interaction of low-density lipoproteins with perfused rabbit aorta]. / Kolichestvennyi analiz vzaimodeistviia lipoproteidov nizkoi plotnosti s perfuziruemoi aortoi krolika.

A method for quantitative analysis of interaction between 125I-LDL with perfused rabbit vessels in situ was developed. The method suggested enables the preservation of the integrity of the endothelium in the perfused vascular segment and the study of 125I-LDL incorporation into the affected vessels within the concentration ranges that make possible specific incorporation of LDL into cells. The method can be applied to studying the mechanisms and modulations of LDL uptake by the vascular wall in situ.

Aortic endothelium of alloxan diabetic rabbits: a quantitative study using scanning electron microscopy.

Scanning electron microscope studies of the aorta and other major arteries have been performed in alloxan-induced diabetic rabbits. After 5 weeks, a variety of structural abnormalities of the endothelial lining were detected including a significant increase in the number of argyrophilic cells and an increased number of craters or openings in the endothelial junctional region. Evidence of more extensive micro-damage was present after 5 months duration of diabetes. These zones with structural changes in the endothelial lining of major vessels seem to be areas of high predilection to atherosclerosis in diabetes.

Quantitative SEM analysis of injury to the endothelium of rabbit aorta and carotid artery during experimental atherosclerosis.

The luminal surface of the aorta and the carotid artery in normal and cholesterol-fed rabbits (3 weeks, 6 weeks, and 8 months of alimentary hypercholesterolemia) was studied by scanning electron microscopy (SEM). To study endothelial injury the vessels were perfused and stained under physiological pressure. The frequency of large and small endothelial defects was determined per surface unit of endothelium in the normal and experimental groups of rabbits. Loss of endothelial cells was regarded as a large defect, argyrophilic cells, craters, and stomata were regarded as small ones. It was found that the percentage of regions without endothelial cells was similar in both control rabbits and in rabbits with experimental atherosclerosis (0.005--0.04% of the total surface examined). The frequency of small endothelial defects increased in rabbits after 3 weeks of hypercholesterolemia but decreased to the control level after 6 weeks of hypercholesterolemia. In rabbits with 8 months of hypercholesterolemia the frequency and area of defects outside plaques did not differ from the control group. In the group with hypercholesterolemia for 8 months 39.2% of the plaque surface contained endothelial cells in which there were no distinct silver-stained cell borders. Kevex X-ray spectrometric data of silver topography indicated that the plaque surface without distinct cell borders was not an area devoid of cells. The data obtained do not support the assumption that morphological endothelial injury is the structural precursor of plaque formation.

[Quantitative analysis of lesions of the aortic and carotid artery endothelium in experimental diabetes in rabbits by scanning electron microscopy]. / Kolichestvennyi analiz povrezhdenii éndotelial'nogo pokrova aorty i sonnoi arterii pri éksperimental'nom sakharnom diabete u krolikov metodom rastrovoi élektronnoi mikroskopii.

A significant increase in the number and zone area of argyrophil cells, craters and stomata of the intracellular formations were seen in the aortic and carotid pectoral and peritoneal regions of rabbits with 5-week alloxan diabetes. The number and zone area of vascular de-endothelization did not increase. Cell polymorphism, apart from maintenance of pronounced argyrophilia and micro-injuries, occurred to diabetes of 5-month standing. Deranged properties of the macrovascular endothelial integument may be of great importance in the pathogenesis of atheromatosis in diabetes mellitus.

[Quantitative study of endothelial defects in the aorta and carotid artery in experimental atherosclerosis]. / Kolichestvennoe izuchenie defektov éndoteliia aorty i sonnoi arterii pri éksperimental'nom ateroskleroze.

The inner surface of the aorta and carotid artery in normal rabbits (group 1) and after 3 weeks (group 2), 6 weeks (group 3) and 8 months (group 4) of hypercholesterolemia was studied by scanning electron microscopy. In all the cases the area of de-endothelialized zones was equally small. Incidence of microdefects in the endothelium (argyrophilic cells, craters and stomata) increased in group 2, but decreased in group 3 and group 4 (outside the plaques). No typical endothelium with argyrophilic borders was observed on 39.2% of the plaque surface in group 4, though the cells were present. The data obtained show that vast zones of de-endothelialization do not precede the development of atherosclerotic plaques.

[Myocardial extraction of nonesterified fatty acids and ketone bodies and their relationship normally and in experimental diabetes mellitus]. / Miokardial'naia ékstraktsiia neésterifitsirovannykh zhirnykh kislot, ketonovykh tel i ikh vzaimootnosheniia v norme i pri éksperimental'nom sakharnom diabete.

It was established in experiments on 20 dogs with diabetes mellitus and 14 control animals that the relationships between glucose-insulin and non-esterified fatty acids-ketone bodies (NEKB) change in the course of diabetes mellitus development. The study of myocardial extraction of NEKB and ketone bodies has shown an increase in their consumption by the myocardium in diabetes mellitus. Intensification of myocardial extraction of ketone bodies was stipulated by elevation of their concentration in the arterial blood and by activation of appropriate enzymes participating in their metabolism. An enhancement of NEKB myocardial consumption seems likely to be due to activation of the appropriate enzymes promoting their utilization.

[Ultrastructural manifestations of early metabolic disorders in the myocardium of dogs with alloxan diabetes]. / Ul'trastrukturnoe proiavlenie rannikh metabolicheskikh narushenii v miokarde sobak pri alloksanovom diabete.

The ultrastructure of dog cardiomyocytes was studied one month after reproducing alloxan diabetes, with respect to myocardial extraction from the blood of glucose, nonesterified fatty acids, beta-lipoproteins and ketone bodies as well as to respiration in conjunction with oxidative phosphorylation of mitochondria, hexokinase and phosphorylase activity. Destructive changes in mitochondria, increased glycogen content in cardiomyocytes were revealed in the absence of glucose consumption by the myocardium which absorbed only lipoid metabolites. Lipoid inclusions were rarely seen in cardiomyocytes. The myocardium showed the increased content of lysosomes and hydrolytic phosphorylase. It is suggested that lipoid metabolites transform to glycogen, with lysosomes participating in the process.

[Morphometric analysis of microangiopathy in dogs with alloxan diabetes]. / Morfometricheskii analiz mikroangiopatii pri alloksanovom diabete u sobak.

Morphometric and morphological analysis of microvascular changes of the mesentery of the small intestine in dogs with alloxan diabetes of one month duration was carried out. A number of changes pointing to functional and structural reconstruction of the microcirculatory bed were revealed.