[Changes of right atrial myoendocrine cells during hypertension and after arterial pressure decrease].

It is well known now that atrial cardiomyocytes carry out both contractile and endocrine activities--they synthesize, accumulate in specific secretory granules and release the natriuretic peptides. The main physiological effects of natriuretic peptides are antagonistic to the renin-angiotensin-aldostrol system, but their role in the development of hypertension is still disputable. The aim of this investigation is to estimate using electron microscopy the secretory activities of atrial myoendocrine cells in rats with inherited stress-induced arterial hypertension (ISIAH stain). It has been shown that myoendocrine cells in the ISIAH rats with arterial pressure about 180 mm Hg reveal morphological features of increased synthesis, extra accumulation and release of natriuretic peptides compared with normotensive control rats. In the ISIAH rats treated with losartan (angiotensin II receptor blocker) and therefore having a sustained decrease in arterial pressure to 140 mm Hg, changes in granular pool composition, reduction of the number and diameter of the secretory granules, reduction of Golgi complexes, and increased intracellular degradation of secretory stores were found in the myoendocrine cells. At the same time the marked capillary hyperemia and interstitial edema in the myocardium were observed. Thus, in rats with severe inherited hypertension, the secretory activity of heart myoendocrine cells is sharply increased and directly depends on the arterial blood pressure level. This proves that natriuretic peptides actively participate in the regulation of hemodynamics during with cardiovascular pathology.

[Ultrastructural estimation facilities of atrial cardiomyocyte secretory activity].

The wide experience in the ultrastructural study of myoendocrine cells of different animal species in normal and experimental conditions allows us to choose the optimal methodology that gives the most complete information about the state of intracellular secretory apparatus. It is revealed that the combined set of atrial myoendocrine cell qualitative and quantitative parameters allows defining the natriuretic regulatory system status, as well as it's acute and chronic responses to hemodynamic changes. The information value of such approach is illustrated by examples of the ontogenetic investigation in two rat lines: with normal arterial blood pressure and with inherited stress-induced arterial hypertension. The proposed methodology is quite sensitive and descriptive; so it is of high importance due to insufficiency of other universal, specific, and accurate methods for cardiac natriuretic peptides investigation.

[Uterine eosinophils and infertility in the rat].

Uterine horn and adnexa structure have been studied with morphologic and morphometric methods in rats on the 10th day after infection of Staphylococcus aureus culture and in rats who became sterile after inflammatory survival. The even-aged intact female rats were used as control. The study demonstrates that nonbearing rats served the fertilization ability, but in genitals the signs of different degree indolent chronic inflammatory process have been observed. Endometrial inability to incorporate the embryonated egg may be determined by complex disturbances, the main of them being the dense eosinophilic infiltration of uterine wall and pathological cell interrelations in endometrium. The insufficient tissue drainage impaired the situation and caused the accumulation of toxic and antigenic substances.

Functional morphology of chorioallantoic vascular network in chicken.

The formation, development, and reduction of the capillary network in the chicken chorioallantoic membrane on days 7-20 of egg incubation were studied by light and electron microscopy with morphometry. Specific features in the architectonics and structure of the mesodermal large vessels and their connection to the suprachoroidal capillaries for provision of adequate gas exchange are shown.

[The state of the lymphatic system in inflammation of the internal sexual organs]. / Sostoianie limfaticheskoi sistemy pri vospalenii vnutrennikh polovykh organov.

In conditions of experimental inflammation of internal sexual organs in female rats fast and adequate reorganization of its lymphatic bed was found. In the nidus of inflammation sufficient drainage of tissues was retained. Loose and widened sinuses of ileal lymph nodes provided sufficient intranodal lymphodynamics. Formation of additional barrier composed of lymphoid cells was detected in paravaginal fat. Reduction of the speed of lymph flow within lymphangions promoted adequate conveyance of toxic lymph to nodes and its further processing. Mobilization of all links of lymphatic barrier resulted in its maximum activation and self recovery by d 14.