The aim of the investigation is to assess the influence of salt load on atrial (ANP) and brain (BNP) natriuretic peptide production in granules of secretory cardiomyocytes in rats.Materials and Methods. The experiments were carried out on 14 white out-bred male Wistar rats weighing 280-300 g. During the experiment all the animals were treated with standard-feed diet and had unlimited access to food and water. NaCl solution was introduced per os in the dose of 1 g per 1 kg of body mass during 14 days. Arterial pressure (AP) was measured noninvasively using a tail-cuff method. ANP and BNP production of atrial cardiomyocytes was studied by means of immunohistochemistry, transmission electron microscopy, immunocytochemistry. There was performed a morphometric analysis of granules containing peptides (A-type -"mature, storing" and B-type -"dissolving").Results. Increase in the number of granules with ANP and decrease in those with BNP accompanied by elevated AP was revealed 14 days after NaCl intake as compared to intact animals.Conclusion. Natriuretic peptides metabolism is regulated by various mechanisms. Early BNP release does not promote AP reduction due to compensatory mechanism disturbance in salt-induced arterial hypertension. Increase in ANP production occurs under the influence of renin-angiotensin-aldosterone system and elevated AP. The present data can indicate adaptive reaction in response to salt loading.

The objective of the present study was to evaluate the structural changes in the capillaries, arterioles, venules, and cardiomyocytes in the myocardium of the rats following the craniocerebral injury (CCI). Eighteen non-pedigree white female rats with the craniocerebral injury were used as the CCI model. All the animals were given an intraperitoneal injection of sodium thiopental (100 mg/kg b.w.) within 3, 7, and 12 days after the injury. The heart was removed after thoracotomy and the myocardial tissue was examined with the light and electron microscopes. It was shown that the rats with the craniocerebral injury developed well apparent changes in the myocardial tissue during the early post-traumatic period that affected not only the blood vessels themselves (capillaries, arterioles, venules) but also the intra- and extravascular structures. Changes in the microcirculatory system included damages to the mitochondria, myofibrils, cell nuclei, sarcoplasmic reticulum, and cardiomyocytes. It is concluded that the morphological changes in the myocardium of the animals associated with the craniocerebral injury can induce the development of functional disorders in the cardiovascular system during the early post-traumatic period.

The aim of the investigation was to study the dynamics of synthesis, accumulation and release processes of atrial (ANP) and brain (BNP) natriuretic peptides on day 60 of experimental renovascular hypertension.Materials and Methods. The experiments were carried put on white non-pedigree male rats. we studied renovascular hypertension using a two-kidney model with the left renal artery ligation. Arterial pressure (AP) was measured via caudal artery using an invasive technique. we analyzed left ventricular cardiac myocyte areas by light optics. Electron microscopic investigation was applied to study the left ventricular and right atrial tissue samples. ANP and BNP accumulation and release processes were assessed using a quantitative analysis of immunolabeled granules of atrial myocytes (А-type, "mature, storing", and B-type, "dissolving") under the transmission electron microscope. we performed a morphometric analysis of morphological types of the left ventricular and right atrial mitochondria.Results. The number of granules containing ANP and BNP in atrial myocytes on day 60 after the left renal artery ligation in rats was found to be no significantly different from that in the intact group. we revealed AP decrease up to the initial level. ANP and BNP content in atrial myocytes and AP recovered against the background of cardiac myocyte hypertrophy, mitochondrial de-energization and destructive changes in microcirculatory bloodstream.Conclusion. In a long-term period of experimental renovascular hypertension, ANP and BNP have a positive effect on AP level falling up to the initial one due to ANP and BNP release on day 30 of the experiment. The efficiency of natriuretic peptides acting as a regulatory component in primary hypertension formation depends on arterial hypertension genesis.

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Цель: оценить структурные изменения капилляров, артериол, венул, внутри и внесосудистые наруше ния в миокарде крыс, перенесших черепно мозговую травму (ЧМТ). Материал и методы.На 18 белых нелинейных крысах самках моделировали ЧМТ. Через 3, 7 и 12 суток после травмы на фоне внутрибрюшинного введения тиопентала натрия осуществляли декапитацию крыс, производили срединную торакотомию и извлекали сердце. Ткань миокарда левого желудочка исследовали с помощью светового и электронного микроскопа.Результаты исследования показали, что у крыс, перенесших ЧМТ, в миокарде формируются изменения стенки микрососудов, которые проявляются в нарушении ее проницаемости, перицеллюлярном отеке, об разовании выростов эндотелия в просвет сосуда, набухании, отеке, истончении и деформации поверхности эндотелиальных клеток, вакуализации и выбухании фрагментов цитоплазмы. Внутрисосудистые измене ния проявляются образованием гиалиновых тромбов, микроагрегатов и сладжей, в обнаружении в просве те сосудов мембранных структур, пузырей и даже полного отсутствия циркуляции в части капилляров (фе номен no refloy). Нарушения за пределами сосудистой стенки проявляются в формировании диапедезных кровоизлияний и развитии выраженного периваскулярного отека. Повреждения микрососудов и, особенно, микрорельефа люминальной поверхности эндотелиоцитов являются значимыми факторами активации со судисто тромбоцитарного звена системы гемостаза.Заключение. Терапия травматической болезни должна быть направлена на своевременную коррекцию патогенетических факторов, вызывающих перестройку цитоскелета эндотелиальных клеток, а также эндо телиальной дисфункции и нарушений микроциркуляции. Ключевые слова: черепно мозговая травма; повреждения капилляров; артериол и венул миокардаAim of the research is to evaluate the structure changes of the capillaries, arterioles, venules and intra and extravascular alterations in myocardium of rats after traumatic brain injury (TBI). Material and methods.Experiments were performed in 18 white male non inbred rats. Midline thoracotomy was performed, and the heart excised under intraperitoneal anesthesia (sodium thiopental) on 3, 7 and 12 days after TBI. Myocardial tissue of the left ventricle was examined under light and electron microscopy.