Aim. To study the morphofunctional state of the colonic wall in rats when using the N–terminal analog of the adrenocorticotropic hormone (ACTH) ACTH6-9-Pro-Gly-Pro (ACTH6-9-PGP) peptide under chronic stress.Materials and methods. The study was performed on 55 male Wistar rats, which were divided into 5 groups (n = 11): group 1 – control group (administration of saline solution without stress); group 2 – chronic restraint stress (CRS) + administration of saline solution; group 3 – CRS + administration of ACTH6-9-PGP at a dose of 5 μg / kg; group 4 – administration of ACTH6-9-PGP at a dose of 50 μg / kg; group 5 – administration of ACTH6-9- PGP at a dose of 500 μg / kg. A histologic examination of the rat colon was performed. The histologic architecture of the colonic wall, the depth of crypts, and the number of goblet cells were assessed. Furthermore, the number of granulocytes, plasma cells, lymphocytes, macrophages, and mast cells was counted.Results. The study demonstrated that chronic (14 days) restraint stress resulted in the development of inflammations in the colonic wall of the animals. Intraperitoneal administration of ACTH6-9-PGP at doses of 50 and 500 μg / kg daily throughout the entire time of stress exposure prevented the development of stress-induced alterations observed in the control animals. At the same time, anti-inflammatory effects of the peptide in the colonic wall and a decrease in the level of corticosterone in the blood serum were noted.Conclusion. The results of this work and data from other studies on the effects of N-terminal analogs of ACTH indicate the need for studying the mechanisms of their effect on inflammation and searching for targets of ACTH6-9-PGP.
Objective: to study the characteristics of heart rate variability in female Wistar rats under conditions of normal wakefulness, moderate physical activity and during recovery. Materials and methods. The study was carried out on 48 female Wistar rats aged 5-6 months. Heart rate variability (HRV) was recorded using Physiobelt 2.5.1 (Neurobotics, Russia). HRV analysis was performed using statistical, geometric, and spectral indicators. Physical activity was created using a two-minute treadmill run at a speed of 15 m/min at an angle of 15°. During the experiment we made 3 records of cardiosignal in each anumal: 1 - before the load, 2 - immediately after the load, 3 - after 15-minute rest. Results. Physical activity led to significant changes in a number of statistical and geometric indexes, but no differences in the spectral indexes of all the records were not found. In this regard, we performed cluster analysis on TP, HF, LF indexes of the record 1 that allowed us to form 2 groups: with low and high spectrum values (LSV and HSV). In each group, we observed significant changes in the values of HRV indexes between the records: in the group with LSV, physical activity led to a change in HR, RRNN, Mo, HF (ms2), LF (ms2, %), VLF (ms2, %), LF/HF, IC, in the group with HSV - HR, RRNN, Mo, Amo, IVR, PAPR, VLF (ms2), LF (%), IC. 15-minute recovery contributed to a further change in the value of HRV parameters. Conclusion. The results of the current study demonstrated that physical activity led to activation of the sympathetic nervous system, mobilization of neurohumoral regulation, as well as a change in the level of regulation of the cardiorhythm from peripheral to the central one. The analysis of HRV parameters in females with LSV and HSV allowed us to establish the features of neurohumoral regulation of the functional state of the organism in groups of animals initially different in spectral characteristics.
One of the manifestations of the stress reaction in the colon is an increase in the permeability of its wall due to the development of an inflammatory reaction against the background of changes in neuroendocrine regulation and microbiota state. These processes are accompanied by significant changes in humoral homeostasis and cell activity involved in the development of an inflammatory response in the colon wall. We performed a literature review to analyze and summarize the available research data on the mechanisms of stress-induced changes in the intestine at the molecular, cellular and tissue levels involving the regulatory systems of the body. Scientific information was searched in Web Of Science, Scopus, ScienceDirect, Medline, Russian Science Citation Index (RSCI), as well as in the search engines Google Scholar, PubMed, Semantic Scholar, Taylor & Francis, Wiley Online Library and Bielefeld Academic Search Engine (BASE). Wall permeability has been shown to have a rather complex regulation involving corticotropin-releasing factor, mast cells, dendritic cells, eosinophils, macrophages, Substance P, nerve growth factor, neurotensin, microbiota metabolic factors (serotonin, short-chain fatty acids, indole derivatives and conjugated fatty acids), epigenetic mechanisms, the HES1 (Hairy/Enhancer of Split-1) - GR (glucocorticoid receptor), and the stress-associated polarity signaling pathway. Under stress, there is a change in the functioning of these mechanisms, leading to an increase in the permeability of the intestinal wall. It results in translocation of bacteria from the lumen into the underlying layers which causes activation of the immune response with subsequent development of an inflammatory reaction. The presented data testify to the prospects and validity of the development of methods of correction of stress-induced shifts in the colon by influencing the central and local mechanisms of realization of the stress response and the state of the microbiota.
Objective: to study the effects of the GHK peptide and its structure analogues on the mechanisms of innate immunity and lipid peroxidation in wound. Materials and methods. The experiments were performed on 70 male Wistar rats. The skin wound was modeled by applying a full-layer wound with an area of 250 mm2 on the animal's back. The peptides Gly-His-Lys (GHK), D-Ala-Gly-His-Lys (D-Ala-GHK), and Gly-His-Lys-D-Ala (GHK-D-Ala) were used in doses of 0.5 μg/kg and 1.5 μg/kg, which it was administered intradermally in doses of 0.5 μg/kg and 1.5 μg/kg in a volume of 0.1 ml for 3, 7 or 10 days. The activity of lipid peroxidation (LPO) processes in blood serum was assessed by the content of malonic dialdehyde (MDA) and acylhydroperoxides (AHP). The antioxidant mechanisms were evaluated by determining the activity of catalase and the total antioxidant activity (OAA) of blood serum. Phagocytic activity of blood neutrophils was assessed by phagocytic index (PI) and phagocytic number (PN). The activity of oxygen-dependent mechanisms in phagocytes was evaluated in a spontaneous nitroblue tetrazolium test (NBT). Results. After the administration of GHK, the tendency to PI, PN and completeness of phagocytosis prevailed, which mainly persisted with the use of peptides D-Ala-GHK and GHK-D-Ala. At the same time, the GHK-D-Ala peptide at a dose of 1.5 μg/kg had the most stable effect on phagocytic activity. The data obtained in the NBT are largely consistent with the PN indicators. At the same time, the effects of structural analogues, unlike GHK, were manifested throughout the experiment. Significantly significant changes in the activity of LPO and antioxidant mechanisms were observed with the use of all peptides. However, their dynamics, orientation and severity throughout the experiment were quite complex. Conclusion. GHK and its structural analogues, D-Ala-GHK and GHK-D-Ala, had an effect on the indicators of innate immunity and LPO in a skin wound, the severity and direction of which depends on the healing period. At the same time, the most pronounced and stable effects were observed when using GHK-D-Ala. That demonstrates the importance of protecting the tripeptide molecule from the action of carboxypeptidases.
Currently, there is no scientifically substantiated information on the occurrence of dental hyperesthesia and its causes in patients who have undergone a new coronavirus infection COVID-19. Objective: to study the occurrence of dental hyperesthesia, to analyze the causes and to find ways to eliminate it in elderly patients after a new coronavirus infection COVID-19. Material and methods. The incidence of dental hyperesthesia was studied in 175 elderly people (from 61 to 75 years old) who had a new coronavirus infection COVID-19 2-4 months ago. As a control group, 125 elderly people were examined, who had not suffered from a new COVID-19 coronavirus infection before their examination. Functional resistance of hard tissues of teeth was assessed using the index of enamel resistance test (TER-test) according to V.R. Okushko and oral hygiene using the simplified index of oral hygiene of Green-Vermillion OHI-S. Results. It has been established that in the postcovid period, dental hyperesthesia is more common in elderly patients, the cause of which is the demineralization of tooth enamel due to the deterioration of individual oral hygiene. Generally accepted oral hygiene in elderly people suffering from dental hyperesthesia contributes to the normalization of the TER-test indicators with a period of 3 to 6 months of regular dental and oral care. The additional use of remineralizing ASEPTА gel for teeth by patients during dental care made it possible to achieve high structural and functional resistance of tooth enamel during the quarter. Conclusion. In people who have undergone a new coronavirus infection COVID-19, due to the deterioration of the hygienic condition of the oral cavity, there is a decrease in the mineralization of hard tooth tissues, which is a factor in the occurrence of dental hyperesthesia and confirms the crystal chemical theory of this pathology. The additional use of remineralizing ASEPTА dental gel for individual dental and oral care makes it possible to achieve high caries resistance of tooth enamel in a shorter time.
Цель исследования: изучение влияния АКТГ 6-9-PGP на уровень депрессивности у крыс в тесте принудительного плавания в сравнении с АКТГ 4-7-PGP. Материалы и методы. Эксперименты выполнены на 90 половозрелых крысах-самцах Вистар массой 250-300 г. Животные были разделены на 9 групп (8 опытных и 1 контрольная) по 10 особей в каждой. В работе применяли физиологический раствор 0,9% натрия хлорида, пептиды АКТГ 6-9-PGP и АКТГ 4-7-PGP, синтезированные в Институте молекулярной генетики РАН. Пептиды вводили однократно внутрибрюшинно за 15 мин до начала тестирования: АКТГ 6-9-PGP в дозах 0,5; 5; 50; 150 и 450 мкг/кг, АКТГ 4-7-PGP в дозах 50; 150 и 450 мкг/кг. Депрессивное поведение крыс оценивали с использованием теста принудительного плавания без отягощения. Результаты. Внутрибрюшинное введение АКТГ 6-9-PGP в дозе 450 мкг/кг способствует уменьшению времени иммобилизации животных и пассивного плавания, а также увеличению длительности их активного плавания, что свидетельствует о наличии антидепрессивного действия пептида. При этом АКТГ 4-7-PGP во всех использованных дозах не оказывал существенного влияния на исследуемые показатели поведенческой активности, а его эффекты ограничивались лишь увеличением времени пассивного плавания. Заключение. Таким образом, установлено, что АКТГ 6-9-PGP, в отличие от АКТГ 4-7-PGP, способен обладать антидепрессивным эффектом. Ключевые слова: регуляторные пептиды; АКТГ; депрессия; принудительное плавание; крысы.
The aim of the study was to provide a comparative assessment of reparative osteogenesis activity and neutrophil func-tion when thymogen, dalargin, Gly-His-Lys (GHK) peptides and their paired combinations were injected into the experi-mental fracture area. Materials and methods. Peptides were administered to Wistar rats in the area of fracture for ten days from the day of injury. Equimolar single doses of the drugs were used: dalargin - 1.2 µg/kg, while thymogen and GHK were injected in a dose of 0.5 µg/kg weight. Reparative activity of osteogenesis was assessed histologically and radiologically. Phagocytic and oxygen-dependent activity of the blood neutrophils was determined. Results. All peptides and their paired combinations increased the activity of reparative osteogenesis. Even more pro-nounced bone repair activity was observed after the injection of GHK peptide in combination with dalargin or thymogen with maximum intensity in animals treated with combined administration of GHK and dalargin. The fracture of the femur bone in experimental rats was also accompanied by a decrease in phagocytic and oxygen-dependent activity of neutrophils. The peptides increased the indices of neutrophils activity more markedly when using paired combinations of peptides and with the manifestation of a corrective effect in animals receiving combined administrations of GHK and dalargin. Conclusion. Synergistic action of Gly-His-Lys peptides, thymogen and dalargin significantly enhances reparative and stimulating neutrophil function in tubular bone fractures and can be used to activate reparative osteogenesis and neutrophil bactericidal activity.
To study the periodontal tissues, inflammatory and dystrophic diseases of which more than 50% of the population of the globe occur, the following methods are used: rheoparadontography, laser Doppler flowmetry, ultrasonic high-frequency Dopplerography (echoosteometry) and others which are often inaccessible for the public health institutions be-cause of the need in special expensive equipment, training and preparation of the equipment. The aim of the work was to correlate the assessment of the periodontal tissues condition in chronic generalized perio-dontitis with the help of modern methods of functional diagnostics and with the help of the test allowing to estimate the gingival capillaries resistance. 152 adult patients 45-56 years old were examined, 36 of them were not diagnosed with perio-dontal pathology, 116 patients had chronic generalized periodontitis of different severity degrees. Capillaroscopy, laser Dop-pler flowmetry, Kulazhenko's test, peripheral blood circulation index in the gingiva were applied in all patients to assess the morphofunctional state of the periodontal tissues. In people suffering from chronic generalized periodontitis the state of the periodontium using the mentioned research methods was also evaluated one month after the completion of the complex treatment. It is shown that the test of Kulazhenko suggested in the last century and the technique of the index evaluation of the peripheral blood circulation in the gingival tissues based on it clearly and reliably correlate with the indices obtained with the help of modern appliances for hemocirculation studies. Therefore, these techniques should retain their relevance for practical dentistry, especially since the use of Kulazhenko's test has a significant positive therapeutic effect on periodontal tissues in its inflammatory pathology, and the use of IPCD allows to objectively assess the effectiveness of therapeutic and preventive measures, including during the dispensary of periodontological patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.