Активность каспазы 3 и каспазы 8 в клетках миокарда правого желудочка при экспериментальной артериальной гипертензии

Caspase-3 and caspase-8 activity in right ventricular myocardial cells of rabbits with experimental arterial hypertension (AH) was investigated. Caspase-3 activity significantly increased at 2 and 4 weeks after modeling of AH. Obtained data demonstrated increased apoptosis in right ventricular myocardial cells in experimental arterial hypertension. Absence of significant increasing of caspase-8 activity indicates the predominance of intrinsic apoptogenic signals.Исследована активность каспазы 3 и каспазы 8 в клетках миокарда правого желудочка сердца кроликов с экспериментальной артериальной гипертензией (АГ). Обнаружено достоверное повышение активности каспазы 3 через 2 и 4 недели после моделирования АГ. Полученные результаты свидетельствуют об усилении апоптотической гибели клеток миокарда правого желудочка при экспериментальной артериальной гипертензии. Статистически незначимое повышение активности каспазы 8 указывает на преобладание внутриклеточного апоптогенного сигнала

Особенности изменения сократительной функции сердца при сочетании экспериментальной артериальной гипертензии с острой коронарной недостаточностью на фоне применения антагонистов кальция

The functional state of cardiovascular system was studied in a rabbit model of acute coronary insufficiency and arterial hypertension treated with Calcium channel blocker verapamil. It was established that the potential working capacity of cardiac left ventricle decreases more significantly in case of 6-week experimental model of arterial hypertension in comparison with acute coronary insufficiency, which affect more considerably the working capacity of the right ventricle. We also assume that the favorable effect of verapamil on the parameters of heart contractile function in case of arterial hypertension with consequent development of acute coronary insufficiency is linked to the preservation of right ventricle's functional reserve.Изучали функциональное состояние сердечно-сосудистой системы кроликов после моделирования острой коронарной недостаточности и артериальной гипертензии и лечения ее верапамилом. Было установлено, что потенциальная работоспособность левого желудочка сердца снижается более значительно при развитии 6-недельной экспериментальной артериальной гипертензии по сравнению с острой коронарной недостаточностью, которая влияет более выражено на работоспособность правого желудочка. Также можно предположить, что положительное влияние верапамила на показатели сократительной функции сердца при артериальной гипертензии и последующим развитием острой коронарной недостаточности связанно с сохранением на фоне приема верапамила функционального резерва правого желудочка

О типовых реакциях поврежденного сердца

On the basis of experimental research we described nine typical (nonspecific) responses of the damaged heart which are initially protective and adaptive but are able to have a pathogenetic character under some certain conditions. These typical responses are as follows: shortening of the effective refractory period of the myocardium, cardiomyocyte mitochondrion swelling, activation of lysosomal apparatus, initial intensification of lipolysis, hypertrophy of cardiac muscle, formation of collagen muffs around blood vessels due to intoxication, functional deafferentation of the heart, changes in the intensity of cardiomyocyte apoptosis, rearrangement of cardiac chronostructure. The represented results can be used as a basis to elaborate some new effective methods of prophilaxis and treatment of heart diseases caused by different etiological factors.На основании экспериментальных исследований выделено девять типовых (неспецифических) реакций поврежденного сердца, первично являющихся защитно-приспособительными, но могущих при определенных обстоятельствах играть и патогенетическую роль: укорочение эффективного рефрактерного периода миокарда, набухание митохондрий кардиомиоцита, активация лизосомного аппарата, инициальное усиление липолиза, гипертрофия сердечной мышцы, образование вокруг миокардиальных сосудов коллагеновых муфт при интоксикациях, функциональная деафферентация сердца, изменение интенсивности апоптоза кардиомиоцитов, перестройка хроноструктуры сердца. Представленные результаты дают основания для разработки новых эффективных методов профилактики и лечения заболеваний сердца различной этиологии

Daytime Exposure to Blue Light Alters Cardiovascular Circadian Rhythms, Electrolyte Excretion and Melatonin Production

Artificial light is characterized by certain features of its impact on the body in terms of its spectral distribution of power, duration of exposure and intensity. Short waves, perceived as blue light, are the strongest synchronizing agent for the circadian system. In the present work, we investigated the features of the circadian rhythms of blood pressure (BP), heart rate (HR), the excretion of electrolytes and the secretion of melatonin in normotensive (Wistar–Kyoto) and hypertensive (SHR) rats under the action of monochromatic blue light in the daytime period. It was found that the exposure of Wistar–Kyoto rats to monochromatic blue light was accompanied by a significant decrease in nighttime and 24 h systolic BP. The most remarkable changes are characteristic of the HR in SHR rats under monochromatic light. A significant decrease in HR in each time period was found, but the predominance of nighttime over daytime values remained in SHR animals. There was also a significant increase in the mesor of the HR in SHR rats. Additionally, the amplitude of diastolic BP and HR, as well as the range of oscillations in HR, were significantly increased compared with the standard light pattern. In contrast to SHR rats, the regulation of the circadian rhythms in Wistar–Kyoto rats was more flexible and presented more changes, which may be aimed at the adaptation of the body to environmental conditions. For Wistar–Kyoto rats, an increase in the level of excreted electrolytes was observed under the action of monochromatic light, but no similar changes were found in SHR rats. For Wistar–Kyoto rats, a significant decrease in the urine concentration of aMT6s in the daytime and nighttime periods is characteristic, which results in the loss of the circadian rhythm. In SHR rats, there was a significant decrease in the nighttime content of aMT6s in the urine, while the daytime concentration, on the contrary, increased. The obtained data demonstrate that prolonged exposure to monochromatic blue light in the daytime period affects the circadian structure of the rhythms of the cardiovascular system, the rhythm of electrolyte excretion and the production of epiphyseal melatonin in wild-type and hypertensive animals. In SHR rats, the rhythms of BP and HR exhibit a more rigid pattern

Analysis of central blood pressure during diphtheria intoxication in rabbits

Diphtheria intoxication was induced in rabbits by a single intravenous injection of native diphtheria toxin in dose of 0.3 MLD/kg, preliminary titrated on guinea pigs. Significant decrease in diastolic and systolic blood pressure and in intraventricular pressure in the left ventricle was established to take place during intoxication. Pulse wave propagation time was prolonged, likely due to prolongation of pressure wave, while the reflection wave appeared at the same time. Reduction of central blood pressure was concluded to result from changes in biomechanical characteristics of the left ventricle, and not to be associated with changes in elastic properties of the arterial wall. © 2009 Springer Science+Business Media, Inc

Blood pressure and contractile function of heart ventricles at the early stages of hypertonic process

In rabbits, arterial hypertension was characterized by progressive elevation of systolic and diastolic blood pressure. The contractile function of the left ventricle augmented, but its potential working capacity decreased. Opposite changes were observed in the right ventricle. It was hypothesized that the compensatory mechanisms in the right ventricle during arterial hypertension are triggered at the very onset of the pathology, while in the left ventricle they develop later. © Springer Science+Business Media, Inc. 2005

Blood pressure and contractile function of heart ventricles at the early stages of hypertonic process

In rabbits, arterial hypertension was characterized by progressive elevation of systolic and diastolic blood pressure. The contractile function of the left ventricle augmented, but its potential working capacity decreased. Opposite changes were observed in the right ventricle. It was hypothesized that the compensatory mechanisms in the right ventricle during arterial hypertension are triggered at the very onset of the pathology, while in the left ventricle they develop later. © Springer Science+Business Media, Inc. 2005

Analysis of central blood pressure during diphtheria intoxication in rabbits

Diphtheria intoxication was induced in rabbits by a single intravenous injection of native diphtheria toxin in dose of 0.3 MLD/kg, preliminary titrated on guinea pigs. Significant decrease in diastolic and systolic blood pressure and in intraventricular pressure in the left ventricle was established to take place during intoxication. Pulse wave propagation time was prolonged, likely due to prolongation of pressure wave, while the reflection wave appeared at the same time. Reduction of central blood pressure was concluded to result from changes in biomechanical characteristics of the left ventricle, and not to be associated with changes in elastic properties of the arterial wall. © 2009 Springer Science+Business Media, Inc

Features of the Structure of the Circadian Rhythm of Blood Pressure and Heart Rate under Genetically Determined Hypertension in the Experiment

In SHR rats of different ages (22, 26, 30, 34, and 38 weeks), continuous 24-h telemetric monitoring of BP and HR was performed. The amplitude and power of oscillations of diastolic BP significantly decreased at the later stages of arterial hypertension (38 weeks), which was considered as a poor prognostic marker. We also observed a significant decrease in the mean daytime, nighttime, and maximum HR and mesor on weeks 30 and 34, but not on week 38, which can reflect triggering of the adaptive response followed by its exhaustion

Characteristics of circadian rhythm of blood pressure during long-term hypertension development in SHR Rats

The specific features of circadian rhythm of BP were investigated in freely moving male SHR rats using telemetry monitoring technique. BP was recorded in the abdominal aorta according to 24-h/4-month schedule. The data were obtained from 22, 26, 30, 34, and 38-week-old animals. Normotensive Wistar rats (22 weeks) served as the control. It was found that the mean 24-h, daytime, and nighttime systolic and diastolic BP in hypertensive rats significantly surpassed the control throughout the observation period and practically did not change during prolonged hypertension. Some prognostically negative changes in the circadian rhythm of the basic hemodynamics system parameters appeared with time. For instance, the maximum 24-h systolic BP significantly increased in comparison with the initial level. © 2013 Springer Science+Business Media New York