Search

This paper shows the results of the study of the effect of temperature on the coagulation processes in the hemostasis of cows and calves. Purpose of the work: comparison of the results of the study of the indicators of the coagulation system of blood of cows and calves of the black-and-brown breed, obtained with the use of medical and veterinary coagulometer, taking into account the age of the animal and its body temperature. The study was conducted in the Vologda region of Russia. The following coagulogram parameters were analyzed: thrombin time, prothrombin time, activated partial thromboplastin time, fibrinogen count. It was found that at physiological temperature on a veterinary coagulometer in the plasma of cows there is a reliable increase in thrombin time by 2.2 times, decrease in prothrombin time by 32.5%, increase in activated partial thromboplastin time by 11.2%, increase in the amount of fibrinogen by 315.4%; in calf plasma - decrease of thrombin time by 7.8%, increase of prothrombin time by 6.2%, increase of activated partial thromboplastin time by 20.9%, increase of fibrinogen amount by 347.6% in comparison with the results obtained during standard incubation at 37°C. The correlation between hemostasis indicators and temperature factor in cows was noticeable (thrombin time, fibrinogen), in calves negative moderate for thromboplastin time, moderate for activated partial thromboplastin time and noticeable for prothrombin time and fibrinogen. The study of coagulation processes in cows and calves using a medical coagulometer led to the results that differ significantly from the reactions occurring in the organism at physiological body temperature. Taking into account the results of the study, it is possible to consider a veterinary coagulometer with the possibility of setting the necessary temperature as a device quite suitable for adequate assessment of hemostasiological parameters in cattle.

The hemostasis system is designed to ensure the integrity of the internal environment of the body and bleeding control and maintain the liquid state of blood in the vasculature. Clinicodiagnostic characterization of clotting in different fish species contains incomplete and scarce information in modern biological science. The data obtained revealed some issues of functioning of the ancient mechanism of blood clotting in these animals in both evolutionary and veterinary aspects. Thus, a comparative study was conducted on the functional state of plasma hemostasis in some commercial fish; namely, cartilaginous ganoids sturgeon (Acipenser baerii), hybrid of sterlet (Acipenser ruthenus), starred sturgeon (Acipenser stellatus), bony - common carp (Cyprinus carpio) and the tilapia, Oreochromis niloticus. The following coagulogram parameter changes were addressed: thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), the concentration of fibrinogen, and soluble fibrin monomer complexes (SFMC). It is assumed that the functioning of the plasma hemostasis system has species specificity regardless of stress resistance, especially in commercial fish at different evolutionary stages. Hence, species-specific characteristics of fish clotting were determined. Activation by the common and extrinsic pathways was several times faster in cartilaginous ganoids (reduced TT by 17.8-26 times, PT by 1.9-2.6 times, reduced fibrinogen concentration by 4.8-6.11 times) than in both the species of bony fish. The hemostasis, with activation of the intrinsic pathway (APTT), was faster in the hybrid and the tilapia by 20.6-16.8 times compared to that in sturgeon, and by 2.8 and 2.2 times compared to carp. The SFMC content in all fish was (1.3-4.3 times) higher than that noted in dogs and 2.5-8.3 times higher than the SFMC content in humans. But, it was lower (1.0-2.4 times) compared to that recorded in cattle. The highest/lowest values of SFMCs were detected in carp and the hybrid of A. ruthenus and A. stellatus, respectively. [ABSTRACT FROM AUTHOR]

Background: The mortality of freshwater fish due to stress during various production manipulations is a severe problem, which requires a thorough understanding of the basic mechanisms involved, including the hemostasis system. Therefore, on the application level, the study of blood clotting can perform fish coagulopathies diagnostics and develop practical preventive and therapeutic anticoagulation methods for fish farming. Aim: The goal of this research was a comparative assessment of the reaction of some hemostasis parameters of two commercial fish species, carp Cyprinus carpio and tilapia Oreochromis niloticus, to the stress of different duration induced by corticosteroids. Methods: The fishes were divided into three groups: chronically stressed (induction by betamethasone), acutely stressed (induction by dexamethasone), and control animals with blood taken from the caudal hemal canal before hormone treatment(by dexamethasone and betamethasone), then 7 and 21 days after. Results and Discussion: Changes in the following parameters were studied: thrombin time, prothrombin time, activated partial thromboplastin time, the concentration of fibrinogen, soluble fibrin monomer complexes, antithrombin. It was found that both hormone-induced stress and handling stress associated with blood sampling strongly increased blood clotting ability in carps (prothrombin time decrease by 78,5-86,1%, fibrinogen increase by 12,7-100%, thrombin time decrease by 83,4-85%, and antithrombin III decreases by 15,3-21,7%), while in tilapias, acceleration of blood clotting by intrinsic and extrinsic pathways were recorded by the end of the experiment only in fishes with imitation of chronic stress (prothrombin time decrease by 76,8%, activated partial thromboplastin time decrease by 20,0%, and 2,3 multiplying soluble fibrin monomer complexes). Conclusions: It was concluded that the adaptive mechanisms of the tilapia (Oreochromis niloticus) organism allowed the clotting function to recover in most cases by the end of the experiment in all groups of fish, in contrast to carps (Cyprinus carpio). Смертность пресноводных рыб в результате стресса при различных манипуляциях на производстве представляет серьезную проблему, что требует глубокого понимания основных задействованных механизмов, в том числе системы гемостаза. На прикладном уровне проведение исследования свертывания крови имеет потенциал для диагностики коагулопатий рыб и разработки практических профилактических и терапевтических противосвертывающих методов для рыбоводства. Цель: Целью этого исследования была сравнительная оценка реакции некоторых параметров гемостаза двух видов промысловых рыб - карпа Cyprinuscarpio и тиляпии Oreochromisniloticus в условиях экспериментальной модели стресса различной продолжительности, индуцированного кортикостероидами. Методы: Рыбы были подразделены на три группы: рыбы с хроническим стрессом (индукция бетаметазоном), острым стрессом (индукция дексаметазоном) и контрольные животные, кровь у которых брали из хвостового гемального канала до обработки гормонами, и далее через 7 и 21 день после. Результаты и Обсуждение: Было исследовано изменение следующих параметров коагулограммы: тромбиновое время, протромбиновое время, активированное частичное тромбопластиновое время, концентрацию фибриногена, растворимых фибрин-мономерных комплексов, антитромбина. Было установлено, что как индуцированный гормонами стресс, так и хэндлинг-стресс, связанным с забором крови, сильно увеличивают свертывающую способность крови у карпов (сокращение протромбинового времени на 78,5-86,1%, увеличение фибриногена на 12,7-100%, сокращение тромбопластинового времени на 83,4-85% и антитромбинаIIIна 15,3-21,7%), тогда как у тиляпий ускорение свертывания крови по внутреннему и внешнему путям к концу эксперимента было зафиксировано только у рыб с имитацией хронического стресса (снижение протромбинового времени на 76,8%, снижение активированного частичного тромбопластинового времени на 20,0%, увеличение фибрин-мономерных комплексов в 2,3 раза). Заключение: Можно отметить, что адаптивные механизмы организма тиляпий позволили свертывающей функции в большинстве случаев восстановиться к концу эксперимента у всех групп рыб, в отличие от карпов. [ABSTRACT FROM AUTHOR]

With stress studies in fish it is often difficult to determine the degree of response to various stressors, and the interpretation of this influence is usually based on an increase in endogenous cortisol levels. Simulation of stress with synthetic corticosteroids is widely used in ichthyological practice, which raises the question of whether endogenous cortisol is the most appropriate parameter for measuring stress levels in such studies. This work presents the dynamics of the plasma cortisol level in simulating acute and chronic stress in 24 carps by a single injection of dexamethasone in the first experimental group and betamethasone in the second experimental group, in comparison with the control group (without injection) for 21 days. The analysis was performed before injection, as well as after 7, 14 and 21 days of treatment. The hormonal response was compared with that of fish stressed by natural factors (hypoxia). It was found that betamethasone inactivates the production of endogenous cortisol during all subsequent days of the experiment after injection from 353.68±66.39 ng/ml to 7.28±1.27 ng/ml by day 21, while the effect of dexamethasone caused multidirectional fluctuations in its level: from 346.25±43.16 ng/ml to 242.25±58.49 ng/ml on the 7th day, 388.25±37.51 ng/ml on the 14th day and 264.25±21.21 ng/ml on day 21 compared with smooth dynamics in control fish: 376.25±44.04 ng/ml, 366.75±42.82 ng/ml, 335.33±8.57 ng/ml and 366.00±89.22 ng/ml, respectively. It was concluded that measuring the level of endogenous cortisol is not recommended when assessing the degree of stress imitation by these hormones, and in studies of this type it is necessary to search for other indicators. [ABSTRACT FROM AUTHOR]

Carp (Cyprinidae) is one of the dominating and most valuable fish species in fish farming. Under conditions of high-intensity cultivation, fish are systematically exposed to extreme factors that cause stress reactions, accompanied by changes in the functional state of the defense of the body systems and exert impact, primarily, on hematological parameters. The hemostatic system is one such defense systems, which counteracts bleeding through a coagulation mechanism. Hemocoagulation follows the same pattern in all vertebrates, from jawless fish to mammals, and represents an ancient adaptation of animals to stressful conditions, often associated with blood loss in nature. This research aimed to study the effect of hormone-induced stress on plasma (secondary) hemostasis in fish. Given the data fragmentation and differences in methodology and conditions, the lack of standardization in studying hemostasis in fish, especially in critical conditions, this problem remains not fully disclosed in global science. The article presents the results of studying carp (Cyprinus carpio) coagulogram parameters under the influence of acute and chronic stress responses, simulated by injections of synthetic cortisol analogs (dexamethasone for short-term stress, and betamethasone for chronic stress) during 21 days. The dynamics of these indicators were analyzed in comparison to intact fish. It has been established that by accelerating the activated partial thromboplastin time, prothrombin time, and increasing the amount of fibrinogen in the blood of fish, blood coagulation processes were clearly accelerated in all groups of animals tested by the last day of the experiment. The dynamics of other parameters, such as the content of soluble fibrin monomer complexes or antithrombin III content, indicated the simultaneous development of hypercoagulation processes in some groups. Assumptions have been made to explain the pattern of changes observed not only in treated fish but also in control animals. [ABSTRACT FROM AUTHOR]