Rats Of Different Ages Research Articles

THE CONTENT OF METALLOPROTEINASE-2 AND METALLOPROTEINASE-9 IN THE SKIN OF RATS OF DIFFERENT AGES AFTER CLOSURE OF THE WOUND BED.

The aim: The aim of the study was to determine the content of metalloproteinase-2 (MMP-2) and metalloproteinase-9 (MMP-9) in the skin of rats of different ages after closure of the wound bed. Materials and methods: The studies were performed on 40 white nonlinear male rats, 20 of which were 3 months old and 20 - 12 months. In each group 10 rats were control and in 10 others facelift operations were performed and cut wounds on the anterior abdominal wall were simulated. On the day of complete healing, the animals were killed, and the skin was cut in the areas of the former wound bed. In control rats, the skin was excised in the same places. The content of MMPs was determined in the skin by enzyme-linked immunosorbent assay. Results: In rats aged 3 months after re-epithelialization of the wound bed, the content of MMP-2 was 17,1% higher compared to control rats but the level of MMP-9 didn't change. In control rats aged 12 months, the levels of MMP-2 and MMP-9 in the skin were 22,9% and 34,4% lower compared to control rats at 3 months of age. In rats 12 months of age after re-epithelialization of the wound bed, the content of MMP-2 and MMP-9 were 92,6% and 102,5% higher compared to control rats. Conclusions: We suggested that the violation of homeostasis between MMPs in rats 12 months of age disrupts wound healing and promotes the formation of pathological scars.

Изучение кожно-резорбтивного действия кожного антисептика на основе поливинилпирролидон-йода

The skin-resorptive effect of a skin antiseptic based on polyvinylpyrollidone-iodine on immature rats of different ages was studied.The skin-resorptive effect of the drug in doses of 5.0 and 0.5 g/kg was revealed on 2–6 week-old rats. The animals showed changes in thyroxine and thyroid-stimulating hormone, as well as general toxic indicators. Absorption of the drug through the skin at a dose of 0.5 g/kg on 4–8 week old rat pups has not been established. The rationale for the use of a skin antiseptic for the hygienic treatment of hands containing PVP-iodine in the age group of children from 8 years old is given. Keywords: toxicity, skin-resorptive effect, immature white rats, skin antiseptic, iodine, thyroxine, thyroid-stimulating hormone.

Вміст факторів росту та фактора 1α, індукованого гіпоксією, в рановому ложі шкіри щурів різного віку

The aim of the study was to determine the content of vascular endothelial growth factor (VEGF), nerve growth factor (NGF) and hypoxia-inducible factor-1alpha (HIF- 1α) in the skin of 40 female rats of different ages (3 and 12 mo) after closure of the wound bed. In each age group composed of 20 rats, 10 rats served as a control group, and in remaining rats a facelift operation was performed and cut wounds on the anterior abdominal wall (5 cm × 0.5 cm) were simulated. The duration of wound surface healing in rats of different age groups was recorded. On the day of complete healing, the animals were killed, and the skin was cut in the areas of the former wound bed. In control rats, the skin was excised in the same places. The content of VEGF, NGF and HIF-1α was determined in the skin by enzyme- linked immunosorbent assay. It was found that in the group of young (3-month-old) rats, complete healing of the wound surface after facelift surgery occurred after 14.0 ± 1.0 days, and on the anterior abdominal wall - after 13.0 ± 1.0 days. In 12-month-old rats, the duration of wound surface healing after facelift surgery and incised wound on the anterior abdominal wall increased to 17.0 ± 1.5 days. In the former wound bed, the content of HIF-1α in young rats increased by 60.7%, and in 12-month-old rats - by 231.6%. In the former wound bed, the content of VEGF and NGF in young rats increased by 14.8 and 11.7%, respectively, and in 12-month-old rats - by 182.4 and 152.6%, respectively. It was concluded that more pronounced hypoxia in the skin after surgery in 12-month-old rats may be the cause of postoperative complications.

Comparative Study on the Effect of Adipose tissue derived Mesenchymal Stem Cells versus Metformin on Age-related Structural Changes of the Cerebellum in Albino Rat

Abstract Introduction Aging is a normal physiological process that affects all organs in the body including the cerebellum. Metformin is an anti-diabetic drug that is used in some age-related diseases. Regenerative medicine using adipose tissue derived mesenchymal stem cells (ADMSCs) is an emerging promising strategy. Aim to compare between the role of ADMSCs and metformin on the age-related structural changes of the cerebellum in female albino rats. Materials and methods Fifty-five female rats of different ages (4, 12 and 24 months) were included in this study. They were divided into three groups according to their ages: Group I (Adult rats), Group II (Old rats) and Group III (Senile rats). Group II and Group III were subdivided into three subgroups, Subgroup a: rats were left without treatment, Subgroup b: rats were given a single dose of 1X106 ADMSCs via tail vein. Subgroup c: Rats received300 mg/kg metformin/day orally. Rats were sacrificed after four weeks. The cerebellum was collected and processed for H&E, Toluidine blue and immuno-histochemical reaction using glial fibrillary acidic protein (GFAP). Results Histological examination of the cerebellum of the subgroups IIa and IIIa revealed age-related structural changes in comparison to group I. Purkinje cells appeared distorted with irregular outline. Some Purkinje cells were seen shrunken while others appeared ballooned. Focal loss of Purkinje cells was also noticed. Granular layer contained small widely separated granule cells. GFAP reaction revealed an apparent decrease in number of astrocytes and their processes. The structural changes were more obvious in subgroup IIIa. In ADMSCs treated subgroups (IIbandIIIb); more noticeable improvement of these changes was noticed compared to the corresponding metformin treated subgroups (IIc and IIIc). Conclusion ADMSCs was more effective than metformin in preventing some age-related structural changes of the cerebellum.

Effects of Early Proinflammatory Stress on Manifestations of Impulsive Behavior in Rats of Different Ages and Sexes

Effects of Early Proinflammatory Stress on Manifestations of Impulsive Behavior in Rats of Different Ages and Sexes

Study on the Relationship between Cardiomyocyte Apoptosis and Left Ventricular Function in Spontaneously Hypertensive Rats

At present, hypertension is a relatively common cardiovascular disease. It not only affects the normal operation of target organs such as the heart and kidneys, but also causes cardiovascular and cerebrovascular diseases, which can lead to death. The apoptosis of cardiomyocytes is widespread in the cardiovascular system and is closely related to vascular diseases. Therefore, the purpose of this article is to explore the relationship between changes in left ventricular function, myocardial multidimensional strain and interstitial fibrosis in spontaneously hypertensive rats (SHR) during cardiomyocyte apoptosis. Whether the research is consistent in terms of order, as the age of hypertensive rats increases, whether there is a close connection between myocardial cell apoptosis and the structure and function of the left heart. The method in this article is to use the method of experimental comparison to randomly group 60 experimental mice and observe the changes of various indicators of rats of different ages, from 12 weeks to 84 weeks. The observations include left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), left ventricular short axis shortening rate (FS), LVEDP, LV+dp/dtmax, LV-dp/dtmax. At the same time, using the TUNEL labeling method, the left ventricular myocardial tissue was sliced, and the apoptosis index of subendocardial and subepicardial myocardial cells was calculated. Then 3 groups were randomly selected from the experimental group, and Western blotting was used to quantitatively detect apoptosis-related the expression of the proteins Bcl-2, Bax, and Fas were compared between the groups. After analysis and determination, it can be found that the apoptosis index of cardiomyocytes is positively correlated with LVMI, CVF, and PVCA (r is 0.83, 0.89, 0.72, respectively, p=0.00). Corresponding conclusions are drawn from the comparison of data. As hypertensive rats grow older, the apoptotic index of cardiomyocytes will continue to increase, and when the myocardial hypertrophy is severe to heart failure, the apoptotic index of cardiomyocytes will increase significantly. This shows that the increase in cardiomyocyte apoptosis is closely related to left heart remodeling, the development of myocardial fibrosis and overall cardiac dysfunction.

INTEGRATIVE CENTRAL NERVOUS SYSTEM ACTIVITY OF RATS IN GERONTOGENESIS UNDER EXPERIMENTAL HYPERGLYCEMIA

Diabetes mellitus has a major impact on the brain and its cognitive function. The pathogenesis of these disorders is still not well understood. Therefore, it is necessary to find ways of solving these manifestations in hyperglycemia in order to prevent the risk of complications that will lead to a worsening of living conditions.
 In the experiment, the state of conditioned-reflex and orientation-research activity of rats of different ages (middle-aged rats and old rats) in conditions of experimental hyperglycemia was found. The animals were kept under standard vivarium conditions. Experimental hyperglycemia was modeled by intraperitoneal solution injection of alloxan monohydrate (120 mg/kg body weight, Sigma). For 10 days, blood glucose was determined using a portable glucometer «Bionime». On day 10, those animals were selected that had a blood glucose value above 28 mmol/L. The analysis of orientation-research and emotional activity was carried out using the «Open Field» technique. The number of squares crossed, the number of lifts on the hind legs, the number of peeking into the burrows, grooming, and the number of bowel movements were recorded. The conditioned passive avoidance technique was used to study the stable and labile phases of memory. In both age groups, the indicators of orientation-research activity differed significantly (p < 0.05). The decrease in the number of squares crossed, the number of racks up and the study of minks was more pronounced in middle-aged animals with diabetes mellitus. The increase in the number of amnesiac animals was also more pronounced in the middle-aged rats of the research group. A decrease in the latency period was noted in both age groups. Thus, it was found that experimental hyperglycemia had pronounced consequences for the cognitive function of animals, respectively, diabetes mellitus has a negative effect on the brain.

Визначення рівня мелатоніну у щурів різної статі та віку при виразковому ураженні шлунка

Метою дослідження було визначення рівня мелатоніну в сироватці крові у щурів різної статі та віку при виразковому ураженні шлунка. Матеріали та методи. Методом спирто-преднізолонового ушкодження моделювали виразкове ураження шлунка та за допомогою імуноферментного аналізу визначали рівні мелатоніну в сироватці крові у щурів різної статі, які були розподілені на групи за віком, а саме — 3, 9, 15 та 20 міс., що відповідає віку людини 14, 29–30, 43–44, 55–56 років відповідно. Результати. Встановлено, що на тлі виразкового ураження шлунка відбувається вірогідне зниження рівня мелатоніну як у самців, так і у самок у всіх вікових групах. Відносно групи контролю у щурів-самців найбільше зниження відбулося у тварин віком 9 та 20 міс. — на 39 та 43 % відповідно (р ≤ 0,05). У самок на тлі виразкового ураження шлунка зниження рівня мелатоніну відносно групи контролю було на 21–23 % (р ≤ 0,05). Обговорення. Отримані результати свідчать, що виразкове ураження шлунка, ймовірно, призводить до пошкодження ентерохромафінних клітин слизової оболонки шлунка, що супроводжується вірогідними зниженнями рівнів мелатоніну у щурів обох статей і всіх вікових груп, та дозволяють припустити, що саме у чоловіків віком 29–30 та 55–56 років виразкове ураження призводить до значного пошкодження екстрапінеальних джерел синтезу мелатоніну та більш тяжкого перебігу виразкової хвороби з розвитком ускладнень. Висновки. Таким чином, виразкове ураження шлунка призводить до зниження рівнів мелатоніну в сироватці крові у щурів різної статі та віку. Найбільше зниження рівнів мелатоніну при експериментальній виразці шлунка відбувається у щурів-самців віком 9 та 20 міс., що відповідає віку людини 29–30 та 55–56 років.

Aging-related severe hypertension induces detrusor underactivity in rats

AimsAging is an obvious risk factor for detrusor underactivity. We investigated the effects of aging on bladder function in spontaneously hypertensive rats. Main methodsMale spontaneously hypertensive rats and Wistar Kyoto rats (used as normotensive controls) at the ages of 18, 36, 54, or 72 weeks were used. Bladder weight, blood pressure, bladder blood flow, and urodynamic and renal parameters were measured. Additionally, detrusor thickness and renal histology were evaluated. Key findingsIn spontaneously hypertensive rats, significant increases were observed in bladder weight/body weight ratio, blood pressure, detrusor thickness, intercontraction interval, urine output, serum creatinine, and renal glomerular and tubular scores, and decreases in bladder blood flow and urine osmolality at 72 weeks as compared to those at 18 weeks. In spontaneously hypertensive rats, significant increases were observed in single voided volume, post voiding residual urine volume, and bladder capacity, with decrease in voiding efficiency were observed at 54 or 72 weeks than at 18 weeks. However, there were no significant differences in blood pressure, urodynamic and renal parameters, detrusor thickness and renal histology among Wistar Kyoto rats of different ages. SignificanceIn spontaneously hypertensive rats, aging induces significant increases in blood pressure, single voided volume, post voiding residual urine volume, intercontraction intervals and urine output, and decreases in voiding efficiency and bladder blood flow indicative of detrusor underactivity. Aging-related severe hypertension could induce voiding dysfunction such as detrusor underactivity via severe bladder ischemia and polyuria. Aged spontaneously hypertensive rats may be useful animal models for detrusor underactivity.

Gut Microbiota Is Involved in Alcohol-Induced Osteoporosis in Young and Old Rats Through Immune Regulation.

Long-term and excessive alcohol consumption are risk factors for osteoporosis. Excessive drinking can reduce bone density and also cause imbalance of gut microbiota. And gut microbiota can affect bone metabolism through various mechanisms, and the regulation of gut microbiota is closely related to age. However, the effects of gut microbiota on alcohol-induced osteoporosis at different ages are unclear. In this study, young and old rats were used to induce osteoporosis by long-term alcohol consumption, and alcohol metabolism, bone morphology, bone absorption and immune activity of rats were analyzed to determine the effects of alcohol on rats of different ages. In addition, changes of gut microbiota in rats were analyzed to explore the role of gut microbiota in alcohol-induced osteoporosis in rats of different ages. The results showed the ability of alcohol metabolism was only associated with age, but not with alcohol consumption. Long-term alcohol consumption resulted in the changes of bone metabolism regulating hormones, bone loss, activation of receptor activator of NF-κB ligand (RANKL) signaling and inflammatory response. And osteoporosis was more severe in old rats than young rats, suggesting that alcohol-induced osteoporosis is age-related. In addition, long-term drinking also affected the composition of gut microbiota in rats, with a significant increase in the proportion of pro-inflammatory microorganisms. Overall, this study found that long-term alcohol consumption induced osteoporosis and affected the composition of gut microbiota. And alcohol can activate T lymphocytes directly or indirectly by regulating the changes of gut microbiota to produce cytokines, and further activate osteoclasts. In addition, the osteoporosis was more severe in the old rats than young rats, which may be due to the higher diversity and stronger regulation ability of gut microbiota in young rats compared with old rats.

Activity of Chymase, Tonin, and Calpains in Tissues of Male and Female Rats of Different Ages

Activity of Chymase, Tonin, and Calpains in Tissues of Male and Female Rats of Different Ages

Ferula elaeochytrisin sıçan kalbinde irisin düzeylerine etkisi

Purpose: The aim of this study was to determine the levels of irisin in the heart, which is a vital organ, in rats of different ages and to reveal whether Ferula elaeochytris (FE) has an effect on the expression of the irisin. 
 Materials and Methods: Our study was designed in six groups, young (4 months), middle age (12 months), old (24 months) rats which were given FE extract for 8 weeks and their control groups. After that their heart tissues were taken and irisin levels were measured by immunohistochemical staining method. 
 Results: The obtained results were analyzed by performing histoscoring. It was observed that the level of irisin in old rats was statistically significantly lower in young and middle age rats. In addition, irisin level of in all groups administered with FE extract was found significantly increased. 
 Conclusion: FE extract increases the level of irisin through other pathways besides its protective effect against tissue damage.

Comparative characteristics of histological changes in lung tissue in rats of different ages under conditions of hyperhomocysteinemia

Annotation. Defeat of the respiratory system is a common phenomenon in today's conditions. Elevated levels of homocysteine (Hz) are one of the predictors of bronchopulmonary pathology. In recent years, there has been an association between its concentration in blood plasma and the risk of developing COPD, bronchial asthma, lung cancer. The pathogenesis of respiratory damage in hyperhomocysteinemia (GHz) is still being studied, but it is known to be the cause of endothelial dysfunction, oxidative stress, endoplasmic reticulum stress, which underlie lung tissue damage. The aim of the study is to establish a comparative characterization of histological changes in the lung tissue of rats of different ages at GHz. The experimental study was performed on 64 white nonlinear male rats. During the experiment, the animals were divided into two groups – control and experimental, each of which is divided into subgroups depending on age – young (1-2 months), mature (6-8 months), old (24-26 months). Simulation of the stable GHz state was achieved by administering to rats the experimental group thiolactone Hz at a dose of 200 mg/kg body weight intragastrically for 60 days. Histological specimens were studied using an SEO CCAN light microscope and photo-documented using a Vision CCD Camera with an image output system from histological specimens. Histological examinations of the lungs of young animals under GHz conditions revealed moderate destructive changes of vessels, bronchi, components of the respiratory department, which were compensatory-adaptive and reversible. Adaptive-compensatory and destructive changes of the organ were found in adult rats at experimental GHz. Older animals develop the most significant destructive-degenerative changes compared with studies of the lungs of groups of young and mature rats. The defining feature for this age group was excessive activation of fibroblasts and the development of perivascular, peribronchial, interstitial sclerosis.

Photoperiod-induced alterations in biomarkers of oxidative stress and biochemical pathways in rats of different ages: Focus on individual physiological reactivity

ABSTRACT Effects of photoperiodicity caused by both the age and individual physiological reactivity estimated by resistance to hypobaric hypoxia on the levels of lipid peroxidation, protein oxidation (aldehydic and ketonic derivatives), total antioxidant capacity, activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase), and biochemical parameters of aerobic and anaerobic pathways in hepatic tissue depending on the blood melatonin level were studied. The study was carried out on 96 6- and 21-month-old male rats divided into hypoxia resistance groups (LR, low resistance, HR, high resistance). The analyses were conducted at four photoperiods: winter (January), spring (March), summer (July), and autumn (October). Our results indicate a significant effect of melatonin, i.e. over 80%, revealed by the complete statistical model of the studied biomarkers of oxidative stress and oxygen-dependent parameters of metabolism. The effects of melatonin vary with age and between photoperiods, which in turn was determined by individual physiological reactivity. In terms of the photoperiods, the melatonin content in the group of the adult animals with low resistance to hypoxia decreased from winter to summer. In a group of old animals in comparison with adults, the melatonin content in all the studied photoperiods was much lower as well, regardless of their hypoxia resistance. In the group of old animals with low resistance to hypoxia, the melatonin content decreased throughout the photoperiods as follows: winter, autumn, summer, and spring. As can be concluded, spring is a critical period for old animals, particularly those with low hypoxia resistance. The important role of melatonin in these processes was also confirmed by our correlation analysis between oxidative stress biomarkers, energy-related metabolites, and antioxidant enzymes in the hepatic tissue of rats of different ages, with different resistance to hypoxia, and in different photoperiods. The melatonin concentration in the blood of highly resistant rats was higher than in those with low resistance to hypoxia. Melatonin determines the individual constitutional level of resistance to hypoxia and is responsible for individual enzymatic antioxidative responses, depending on the four photoperiods. Our studies have shown that melatonin levels are related to the redox characteristics of antioxidant defenses against lipid peroxidation and oxidative modification of proteins in old rats with low resistance to hypoxia, compared to a group of highly resistant adults. Finally, the melatonin-related mechanisms of antioxidative protection depend on metabolic processes in hepatic tissue and exhibit photoperiodical variability in adult and old rats.

Performance of food seeking behavior in rats of different age

The ability of juvenile rats to seek food behavior in radial maze with asymmetrical rein-forcement following injection of pharmacological drugs selectively affecting the hippocampal or striatal activity was investigated. It has been shown that the ability of animals to form selective attention on significant sensory signals and the animal efficiency to wait the delayed discrete reinforcement appeared in rats on the different phases of age where hippo-campus and striatum are in competition each to another.

Study on the Safety of Human Oligodendrocyte Precursor Cell Transplantation in Young Animals and Its Efficacy on Myelination.

Oligodendrocyte precursor cells (OPCs) can differentiate into myelinating oligodendrocytes during embryonic development, thereby representing an important potential source for myelin repair or regeneration. To the best of our knowledge, there are very few OPCs from human sources (human-derived OPCs [hOPCs]). In this study, we aimed to evaluate the safety and remyelination capacity of hOPCs developed in our laboratory, transplanted into the lateral ventricles of young animals. Several acute and chronic toxicity experiments were conducted in which different doses of hOPCs were transplanted into the lateral ventricles of Sprague–Dawley rats of different ages. The toxicity, biodistribution, and tumor formation ability of the injected hOPCs were examined by evaluating the rats' vital signs, developmental indicators, neural reflexes, as well as by hematology, immunology, and pathology. In addition, the hOPCs were transplanted into the corpus callosum of the shiverer mouse to verify cell myelination efficacy. Overall, our results show that transplanted hOPCs into young mice are nontoxic to their organ function or immune system. The transplanted cells engrafted in the brain and did not appear in other organs, nor did they cause tissue proliferation or tumor formation. In terms of efficacy, the transplanted hOPCs were able to form myelin in the corpus callosum, alleviate the trembling phenotype of shiverer mice, and promote normal development. The transplantation of hOPCs is safe; they can effectively form myelin in the brain, thereby providing a theoretical basis for the future clinical transplantation of hOPCs.

Ультраструктурні зміни пінеальних клітин епіфіза за умов тривалої дії нітратів питної води та засобів корекції

According to modern data, the epiphyse (pineal gland) is an organ that combines the processes of adaptogenesis and immunogenesis, takes part in triggering stress reactions and determines the sequence of disorders in the body at different stages of stress development. Researchers consider the pineal gland to be the most important organizer of biological rhythms associated with photoperiodism and the organ that determines the stereotype of the organism. Its individual functions are rhythmically variable under the influence of the environment and age. The purpose of the study was to study the structural and functional changes of pineal cells of the pineal gland in rats at different stages of normal development, under the action of nitrates and the simultaneous action of nitrates and methylene blue. Materials and methods. In accordance with the purpose of the work, the study was carried out on 90 nonlinear white male rats of different ages. The animals were kept in the vivarium in equivalent conditions. Long-term exposure to nitrates on the body of animals was achieved by daily introduction into the drinking ration, starting from the 7th day of postnatal development of rats (after preliminary water purification), 120 mg/l sodium nitrate, that is, in a dose that is typical for many regions of Ukraine. When simulating the action of methylene blue, this substance was daily orally administered to the animals in doses: 0.1-0.15 ml of a 1% aqueous solution per 1 kg of body weight. Results and discussion. As a result of the 7-day action of nitrates in 14-day-old rats, structural changes were observed in the pineal gland, which corresponded to a decrease in the function of light cells and an increase in the functional activity of type II pinealocytes. The ultrastructure of the cytoplasm of type I pinealocytes contained poorly developed organelles and single secretory granules. In 45-day-old animals exposed to nitrates in light pinealocytes, pronounced disturbances in membrane organelles, primarily in mitochondria and the granular endoplasmic reticulum, were noted. The functional activity of dark pinealocytes increased during this period of the study. In the pineal parenchyma of 90-day-old rats after exposure to nitrates, the functional activity of type I pinealocytes was at a low level. The functional activity of dark pinealocytes was also weakened. Thus, as a result of the simultaneous action of nitrates and methylene blue in the pineal gland of 14-day-old rats, a tendency to gradual restoration of the structural and functional parameters of cells was observed. In 45-day-old animals, after the simultaneous action of nitrates and methylene blue, the ultrastructural data of pineal cells indicated numerous mitochondria and secretory granules in the cytoplasm. In the parenchyma of the pineal gland of 90-day-old rats after chronic action of nitrates and methylene blue at the ultrastructural level, no sharp changes in the cytoplasm and nucleus of light and dark pinealocytes were found in comparison with the control. Conclusion. The intake of nitrates in 14-day-old rats causes the development of a stress reaction, poorly developed organelles and signs of degranulation appear in the ultrastructure of light pinealocytes, however, the cytoplasm and nuclei of dark cells indicated an increase in function. In 45-day-old rats after exposure to nitrates, the signs of the stress reaction are enhanced. In the ultrastructure of the cytoplasm of light cells, pronounced violations of membrane organelles are determined. Enhanced function continues in dark pinealocytes. After the action of nitrates in 90-day-old rats, changes occur that are characteristic of the stage of depletion of the general adaptation syndrome, the result of which is a deep imbalance in the work of the pineal gland. The combined action of nitrates and methylene blue in 14-day-old animals helps to reduce the toxic effect and the strength of stress reactions in the pineal gland. In the ultrastructure of pinealocytes, the number of ribosomes, small secretory granules and mitochondria increases in comparison with the action of nitrates alone. In 45-day-old animals with the simultaneous intake of nitrates and methylene blue in the ultrastructure of melanotropic cells, the accumulation of secretory granules of the same size and electron density, an increase in the number of organelles and signs of restoration of the structure of the cytoplasm and nucleus are noted. The use of methylene blue against the background of long-term intake of nitrates in 90-day-old rats at the ultrastructural level of abrupt changes in the cytoplasm and nucleus of light and dark pinealocytes is not manifested in comparison with the control

Dynamics of connective tissue metabolites in the blood of rats of different age under hypokinesia

Topicality. Hypokinesia is a condition of insufficient motor activity of the body with limited pace and volume of movement, and is currently the fourth leading cause of endemic death in the world. It is known that hypokinesia can affect the metabolism of components of bone and cartilage, which is the basis for the development of pathological processes, but there are no biochemical markers of this process in the literature. Thus, currently, there is insufficient number of experimental scientific works devoted to the study of biochemical parameters characterizing the state of the connective tissue in the experiment to assess the impact of hypokinesia on the body, and this fact determines the relevance of the study. Aim. To study the dynamics of the main metabolites characterizing the state of the connective tissue in the blood serum in hypokinesia in rats of different ages. Materials and methods. The studies were performed on 42 white male rats aged 3 and 12 months, kept in the vivarium of the Sytenko Institute of Spine and Joint Pathology National Academy of Medical Sciences of Ukraine, Kharkiv. The conditions of hypokinesia were reproduced using a specially designed device that limited the mobility of the animal without disturbing the ventilation of the body. Animals were removed from the experiment by decapitation in Day 7 and 30 of immobilization under thiopental anesthesia. The content of sialic acids in the serum was determined by the Hess method, chondroitin sulfate – by Nemeth-Csoka method modified by L. I. Slutsky, the fractional composition of glycosaminoglycans (GAG) – by the reaction with resoquine. Results and discussion. In the study of the rat serum, it was found that in intact animals of 3 and 12 months of age the content of sialic acids was different; it was 2.94 ± 0.16 and 1.98 ± 0.09 mmol/L, respectively. After 7 days of hypokinesia, their concentration in young animals did not change, but in older animals, this figure increased. By Day 30, the serum sialic acid levels suddenly increased compared to intact animals. In animals of 12 months of age, the concentration of sialic acids in the blood serum increased by both Day 7 and Day 30 of hypokinesia, especially at the end of the experiment. Hypokinesia also showed a significant increase in serum concentrations of chondroitin sulfates on Day 7 of the experiment in animals of both age groups. At the same time, the level of these metabolites on Day 30 was at the same level. In young rats on Day 7 the fraction of GAG remained unchanged, but on Day 30 there was a significant decrease. During this period, the second fraction of GAG increased. In animals aged 12 months on Day 7 and 30, the content of most GAG fractions was lower than the values characterizing the fractional composition of GAG in intact rats. Conclusions. Thus, the determination of sialic acids, GAG fractions and chondroitin sulfates in the serum can be presented as a set of biochemical tests to assess disorders of the connective tissue metabolism while limiting the motor activity of the body. It has been found that the 30-day hypokinesia causes significant disorders of the connective tissue, and it is reflected in changes in the biochemical parameters of the serum of experimental rats.

State of the Antioxidant System and the Severity of Lipid-Peroxidation Processes in the Myocardium and Blood Plasma of Rats of Different Ages with Postinfarction Cardiosclerosis

State of the Antioxidant System and the Severity of Lipid-Peroxidation Processes in the Myocardium and Blood Plasma of Rats of Different Ages with Postinfarction Cardiosclerosis

Effects of Early Proinflammatory Stress on Anxiety and Depression-Like Behavior in Rats of Different Ages

Early proinflammatory stress created by administration of lipopolysaccharide (LPS) (50 μg/kg s.c.) on days 3 and 5 of postnatal life led to decreases in movement activity, reductions in exploratory behavior, and increases in anxiety in rats at adolescent age (1–1.5 months) in the open field and elevated plus maze tests. Greater changes in anxiety behavior were seen in males than females. Administration of LPS in early ontogeny induced signs of depression-like behavior at adolescent age in both males and females, this being detected in the anhedonia test as a reduction in the preference for 1% sucrose solution, unlike the situation in the control groups. The forced swimming test showed signs of depression-like behavior in males but not in females, but only on first testing. In adult rats (3–3.5 months), after increased handling and acquisition of food-procuring reflexes, these changes in anxiety and depression-like behavior largely disappeared. Administration of LPS at early age led to increased serum IL-1β levels in adult males after repeated stress exposure, while females showed increased corticosterone levels as compared with control animals. These results provide evidence of increased signs of anxious-depressive behavior in rats after early exposure to proinflammatory stress, along with sex-related differences and the possibility of correcting the negative consequences of stress in later life.