Naringenin Prevents Renal Injury in Experimental Hyperuricemia Through Suppressing Xanthine Oxidase, Inflammation, Apoptotic Pathway, DNA Damage, and Activating Antioxidant System.

Background/Purpose: This research was performed to determine the effect of naringenin (NAR) in experimental hyperuricemia (HU) induced by potassium oxonate (PO) on uric acid levels and xanthine oxidase (XO), inflammation, apoptotic pathway, DNA damage, and antioxidant system in kidney tissue. Study Design: Wistar Albino rats were categorized into four groups: (1) Control group, (2) PO group, (3) [PO+NAR] (2 weeks) group, and (4) PO (2 weeks)+NAR (2 weeks) group. Methods: The first group was not administered any drug. In group 2, PO was administered intraperitoneally 250 mg/kg/day for 2 weeks. In the third group, 100 mg/kg/day NAR was given intraperitoneally 1 hr after PO injection for 2 weeks. In the fourth group, PO was injected for the first 2 weeks, followed by NAR injection for the second 2 weeks. Serum uric acid levels, XO, nuclear factor-kappa B, tumor necrosis factor-alpha, interleukin-17, cytochrome c, 8-Hydroxydeoxyguanosine (8-OHdG), glutathione peroxidase (GPx), and caspase-3 levels in kidney were determined. Results: HU increased the levels of inflammatory and apoptotic parameters, XO, and 8-OHdG levels in kidney. Administration of NAR caused a decrease in these values and an increase in GPx levels. Conclusions: The results of the study show that NAR treatment reduces serum uric acid levels, and apoptosis, inflammation, and DNA damage; increases antioxidant activity in kidney in experimental HU.

Role of exogenous putrescine in the status of energy, DNA damage, inflammation, and spermidine/spermine-n(1)- acetyltransferase in brain ischemia-reperfusion in rats.

Objectives: This study aims to investigate the role of putrescine against brain ischemia-reperfusion (IR) injured rats administered with 250 µmol/kg exogenous putrescine and highlight the IR-associated mechanisms in energy metabolism and inflammatory pathway. Materials and Methods: The rats were divided into six groups: 1-Sham group; 2-IR group, 30 min of ischemia and 30 min of reperfusion was performed with bilateral carotid occlusion (BCAO); 3-IPR group, a single oral dose of putrescine was administered at the start of the 30-minute reperfusion; while in the other treatment groups, 4 doses of putrescine were given within 12-hour intervals. After 30 min of reperfusion, the first dose was administered immediately in the IR-PI (group 4), after 3 hr in IR-PII (group 5), and after 6 hr in IR-PIII (group 6). Interleukin-6 (IL-6), Nuclear factor NF-kappa-B (NF-kB), Adenosine triphosphate (ATP), total Nitric oxide (NO), 8-hydroxyguanosine (8-OHdG), Spermidine/Spermin N-acetyltransferase (SSAT) levels were analyzed in brain tissues. Results: IR reduced brain ATP levels; however, putrescine treatment reversed this state. Brain NO and 8-OHdG levels, and NF-kB and IL-6 levels increased significantly in the IR group and these elevations were decreased in putrescine administered groups. SSAT levels were higher in the IR-PII group. The lowest levels were observed in the IR-PIII group. Conclusion: The exogenous putrescine supplementation after cerebral IR creates neuroprotective effects independent of the time of administration; according to conditions such as formation of radicals in the brain, the spread of the inflammation and the need for consumption of energy are considered as a whole.

Naringenin Prevents Inflammation, Apoptosis, and DNA Damage in Potassium Oxonate-Induced Hyperuricemia in Rat Liver Tissue: Roles of Cytochrome C, NF-κB, Caspase-3, and 8-Hydroxydeoxyguanosine.

Background: Hyperuricemia (HU) is a metabolic disease characterized by high uric acid levels in the blood. HU is a risk factor for diabetes, cardiovascular complications, metabolic syndrome, and chronic kidney disease. Purpose: The present study was performed to determine the effect of experimental HU on xanthine oxidase (XO), tumor necrosis factor-alpha (TNF-α), nuclear factor-kappa B (NF-κB), interleukin-17 (IL-17), cytochrome C, glutathione peroxidase (GPx), caspase-3, and 8-hydroxydeoxyguanosine (8-OHdG) levels in liver tissues of rats. Study Design: Thirty-five, male, Wistar albino-type rats were used for this study. Experimental groups were formed as follows: Group 1: control group; Group 2: potassium oxonate (PO) group; group 3: PO+NAR (naringenin; 2 weeks) group; and Group 4: PO (2 weeks)+NAR (2 weeks) group (total of 4 weeks). Methods: The first group was not given anything other than normal rat food and drinking water. In the second group, a 250 mg/kg intraperitoneal dose of PO was administered for 2 weeks. In the third group, 250 mg/kg intraperitoneal PO (application for 2 weeks) and 100 mg/kg NAR intraperitoneally 1 hr after each application were administered. In the fourth group, intraperitoneal PO administration was applied for 2 weeks, followed by intraperitoneal administration of NAR for 2 weeks (4 weeks in total). At the end of the experimental period, XO, TNF-α, NF-κB, IL-17, cytochrome C, GPx, caspase-3, and 8-OHdG levels were determined in liver tissues. Results: HU increased XO, TNF-α, NF-κB, IL-17, cytochrome C, caspase-3, and 8-OHdG levels in liver tissues. However, both 2 and 4 weeks of NAR supplementation decreased these values, and also NAR supplementation led to an increase in GPx levels in tissues. Conclusions: The results of the study show that increased inflammation, apoptosis, and DNA damage in experimental HU can be prevented by administration of NAR due to inhibition of cytochrome C, NF-κB, caspase-3, and 8-OHdG.

Increased apoptosis, tumor necrosis factor-α, and DNA damage attenuated by 3',4'-dihydroxyflavonol in rats with brain Ischemia-reperfusion.

OBJECTIVES: This research was aimed to find out the effects of 3',4'-dihydroxyflavonol (DiOHF) on apoptosis, DNA damage, and tumor necrosis factor-α (TNF-α) levels in the frontal cortex of rats with induced experimental brain ischemi reperfusion. MATERIALS AND METHODS: A total of 38 Wistar albino male rats were used. Groups were created as 1-Sham; 2-Ischemia-reperfusion (I/R); 3-I/R + DiOHF (10 mg/kg); 4-Ischemia + DiOHF + reperfusion; 5-DiOHF + I/R. I/R was performed by carotid artery ligation for 30 min in anesthesized animals. Following experimental applications, blood samples were taken from anesthetized rats to obtain erythrocyte and plasma. Later, the rats were killed by cervical dislocation, and frontal cortex samples were taken and stored at - 80oC for the analysis. RESULTS: In the ischemic frontal cortex tissue sections degenerate neuron numbers, Terminal deoxynucleotidyl transferase-dUTP nick end labeling (TUNEL) positive cell ratio and caspase-3 positive cell ratio increased. Malondialdehyde, TNF-α, and 8-OHdG levels were increased in both plasma and tissue in ischemia group, whereas tissue and erythrocyte glutathione levels were significantly suppressed. However, these values were significantly reversed by DiOHF treatment. CONCLUSION: The results of the study showed that I/R significantly increased apoptosis, TNF-α, and DNA damage in rats with brain I/R. However, 10 mg/kg intraperitoneal DiOHF treatment improved deterioted parameters.

The Effect of Zinc and Melatonin Administration on Lipid Peroxidation, IL-6 Levels, and Element Metabolism in DMBA-Induced Breast Cancer in Rats.

The purpose of this study was to investigate the effects of zinc and melatonin administration on interleukin-6, lipid peroxidation parameters, and element metabolism in DMBA-induced breast cancer in female rats. A total of 42 recently weaned Wistar rats were divided into 5 groups as follows: control (group 1), DMBA control (group 2), DMBA + zinc (group 3), DMBA + melatonin (group 4), and DMBA + melatonin and zinc (group 5). Malondialdehyde (MDA) and glutathione (GSH) levels in breast tissue and blood samples were determined via spectrophotometric methods. In addition, iron, magnesium, zinc, and copper levels in serum samples were determined by atomic emission, and plasma interleukin-6 levels were determined by ELISA method. The highest tissue and plasma MDA and the lowest tissue and erythrocyte GSH levels found in the study were in group 2; the highest tissue and erythrocyte GSH levels and the lowest tissue and plasma MDA levels are in group 5 (P < 0.05). Iron, magnesium, and zinc levels of groups 3, 4, and 5 were higher than the DMBA group without administration (group 2), but the copper values were significantly lower (P < 0.05). The highest IL-6 levels were determined in group 2 while IL-6 levels in the DMBA group (G5) treated with combined melatonin and zinc were lower than all other breast cancer groups (P < 0.05). According to the findings obtained in this presented study, combined zinc and melatonin therapy can contribute to the prevention of tumor growth by improving the disruption in element metabolism and suppressing IL-6 levels and reducing tissue damage that causes the cancer.

The effect of thyroid dysfunction and treatment on adropin, asprosin and preptin levels in rats.

OBJECTIVES: Thyroid hormones have important roles in normal development and energy regulating mechanisms as well as signaling mechanisms that affect energy consumption through central and peripheral pathways. The aim of this study was to determine the effects of thyroid dysfunction on adropin, asprosin and preptin levels in rat. METHODS: The study was performed on the 38 male Wistar-albino rats. Experiment groups were designed as follows. 1-Control, 2-Hypothyroidism; To induce hypothyroidism PTU was applied by intraperitoneal as 10 mg/kg/day for 2 weeks. 3-Hypothyroidism + Thyroxine; Previously animals were made with hypothyroidism by 1 week PTU application and then 1 week l-thyroxine was given by intraperitoneal as 1.5 mg/kg/day. 4-Hyperthyroidism; Rats were made with hyperthyroidism by 3 weeks l-thyroxine (0.3 mg/kg/day). 5-Hyperthyroidism + PTU; Animals were made hyperthyroisim by l-thyroxine as groups 4, then 1 week PTU was applied to treatment of hiperthyrodism. At the end of supplementation animals were sacrificed and blood samples were collected for FT3, FT4, adropin, asprosin, preptin analysis. RESULTS: FT3 ve FT4 levels were reduced significantly in hypothyroidism while increased in hyperthyroidism (p<0.001). Hipothyrodism led to reduces adropin, asprosin and preptin levels. And also hyperthyroidism reduced adropin and preptin levels (p<0.001). CONCLUSIONS: The results of study show that experimental hypothyroidism and hyperthyroidism lead to significantly change to adropin, asprosin and preptin levels. However, correction of thyroid function caused to normals levels in asprosin and preptin.

The Roles of Flavonols/Flavonoids in Neurodegeneration and Neuroinflammation.

The inflammatory process in the human body is a physiological response involving many cellular types and mediators. It results in scar formation to separate the damaged area from the surrounding healthy tissue. Because of increased blood-brain barrier permeability following inflammation, leukocytes infiltrate the CNS and are also supplemented by proinflammatory mediators. However, an acute inflammatory process after cerebral trauma or stroke may also result in a prolonged lesion formation, leading to a severe neuronal loss. The prolonged inflammatory process in the CNS may cause serious damage to the neuronal system. It may lead to CNS damage in such a way that endangers functional integration and proinflammatory system balance. Effects of different flavonoid species on ischemia-reperfusion injury and cognition and function have also been shown in experimental studies. Flavonoids are presented broadly in plants and diets. They are believed to have various bioactive effects including anti-viral, anti-inflammatory, cardioprotective, anti-diabetic, anti-cancer, anti-aging, etc. Quercetine is the predominant dietary flavonoid. Main sources are tea, onion, and apple. It is demonstrated that the frequently consumed food like soybean, peanut, mustard, rice, sesame, olive, potatoes, onion, and oats contain flavonoids. Catechin and its derivates which are isolated from tea leaves have antioxidant activity but in low doses, their prooxidant effects are also reported. Ipriflavone which is a synthetic flavonoid may increase total calcium in bone. In this review, the effects of flavonoids species on the inflammatory process in the neurodegenerative process were examined as general.

Aquaporins and Roles in Brain Health and Brain Injury.

In the literature screening, aquaporins were found in the cerebral structures including the pia mater, choroid plexus, ependyma, piriform cortex, hippocampus, dorsal thalamus, supraoptic and suprachiasmatic nuclei, white matter and subcortical organ. Among these, the most common are AQP1, AQP4, and AQP9. The roles of aquaporins have been demonstrated in several diseases such as cerebral edema, various central nervous system tumors, Alzheimer's Disease and epilepsy. In this review, the relationship between brain/brain-injury and aquaporin, has been reviewed.

Effect of 3'-4'-dihydroxyflavonol on lipid per oxidation in experimental renal ischemia-reperfusion in rats.

This study aimed to examine the affects of 3'-4'-dihydroxyflavonol (DiOHF) on lipid peroxidation in experimental renal ischemia-reperfusion. The research was conducted on Wistar-albino type male rat. The experimental groups were formed as 1.Control; 2.Sham; 3.Ischemia; 4.Ischemia+reperfusion; 5.DiOHF+Ischemia; 6.Ischemia+ DiOHF + reperfusion. The highest tissue glutathione levels were found in groups 5 and 6. Groups 1 and 2, which were control and sham groups respectively, had the lowest tissue GSH values. Ischemia group was found to have the highest tissue malondialdehyde (MDA) level. Tissue MDA levels in group 4 were lower than those in group 3, however, higher than the levels in all other groups. Erythrocyte GSH levels in groups 5 and 6 were higher than the levels in all other groups. Group 4 has highest plasma MDA values. Plasma MDA levels in group 3 were lower than the levels in Group 4, but higher than those in other groups. The results of the study indicate that intraperitoneal DiOHF administration inhibits lipid per oxidation that intensifies in the case of renal ischemia-reperfusion injury in rats.

The effects of zinc and melatonin on muscle ischaemi-reperfusion injury in rat.

Ischemia-reperfusion leads to damage in cell or tissue due to insufficient blood flow. The aim of present study was to determine the effect of zinc, melatonin and zinc + melatonin supplementations during 3 weeks on muscle tissue and plasma MDA and GSH levels. This study was performed on 38 male Wistar-Albino rats. Experiments groups were designed as sham-control, ischemia-reperfusion (I/R), zinc + I/R, melatonin + I/R and zinc + melatonin + I/R Ischemia-reperfusion was induced by left femoral artery occlusion (1 hour) and reopening (1 hour).  At the end of experiments tissue and blood samples were analysed for MDA and GSH. MDA levels were increased, GSH levels decreased in I/R groups. However, zinc and melatonin supplementation inhibited  MDA and increased GSH levels in I/R groups. The results of present study show that increased lipid peroxidation in muscle tissue by ischemia-reperfusion may be prevented by zinc and melatonin or zinc plus melatonin supplementation.

Melatonin has a protective effect against lipid peroxidation in the bone tissue of diabetic rats subjected to acute swimming exercise.

Aim The present study aimed to examine the effects of melatonin supplementation on lipid peroxidation in the bone tissue of diabetic rats subjected to acute swimming exercise. Methods The study was conducted on 80 Sprague-Dawley type adult male rats which were equally allocated to eight groups: group 1, general control; group 2, melatonin-supplemented control; group 3, melatonin-supplemented diabetic control; group 4, swimming control; group 5, melatonin-supplemented swimming; group 6, melatonin-supplemented diabetic swimming; group 7, diabetic swimming; group 8, diabetic control. In order to induce diabetes, the animals were subcutaneously injected with 40 mg/kg streptozotocin (STZ). The animals were supplemented with 3 mg/kg/day melatonin intraperitoneally (IP) for 4 weeks. At the end of the study, the animals were decapitated to collect bone tissue samples which were examined to find out the malondialdehyde (MDA) (nmol/g/protein) and glutathione (GSH) (mg/dL/g protein) levels. Results The highest MDA values in the bone tissue were found in groups 7 and 8. MDA levels in the bone tissue in groups 3 and 6 were lower than the levels in groups 7 and 8, but higher than those in all other groups. Groups 3, 5 and 6 had the highest bone tissue GSH values. On the other hand, the lowest GSH level was established in groups 7 and 8. Conclusion The results of the present study indicated that the cell damage caused by acute swimming exercise and diabetes in the bone tissue could be prevented by melatonin supplementation.

Zinc Metabolism and Metallothioneins.

Among the trace elements, zinc is one of the most used elements in biological systems. Zinc is found in the structure of more than 2700 enzymes, including hydrolases, transferases, oxyreductases, ligases, isomerases, and lyases. Not surprisingly, it is present in almost all body cells. Preserving the stability and integrity of biological membranes and ion channels, zinc is also an intracellular regulator and provides structural support to proteins during molecular interactions. It acts as a structural element in nucleic acids or other gene-regulating proteins. Metallothioneins, the low molecular weight protein family rich in cysteine groups, are involved significantly in numerous physiological and pathological processes including particularly oxidative stress. A critical role of metallothioneins (MT) is to bind zinc with high affinity and to serve as an intracellular zinc reservoir. By releasing free intracellular zinc when needed, MTs mediate the unique physiological roles of zinc. MT expression is induced by zinc elevation, and thus, zinc homeostasis is maintained. That MT mediates the effects of zinc, besides having strong radical scavenging effects, points to the critical part it plays in oxidative stress. The present review aims to give information on metallothioneins, which have critical importance in the metabolism and molecular pathways of zinc.

The effect of zinc and melatonin supplementation on immunity parameters in breast cancer induced by DMBA in rats.

OBJECTIVE: The aim of the study was to determine the effects of zinc and melatonin supplements on the immunity parameters of female rats with breast cancer induced by DMBA. METHODS: Group 1; Control, Group 2; 7,12-dimethylbenz[a]anthracene (DMBA), Group 3; DMBA + zinc, Group 4; DMBA + melatonin, Group 5; DMBA + zinc + melatonin. The rats' breast cancer was induced by DMBA 80 mg/kg. Groups 3-5 received daily 5 mg/kg doses of zinc, melatonin, and zinc + melatonin, respectively. Lymphocyte rates, T-lymphocyte subgroups, B-lymphocyte and natural killer cells (NK), and natural killer T (NKT) were evaluated. RESULTS: The most significant increase in lymphocyte, T-lymphocyte, and CD4 lymphocyte rates was found in Group 5. The highest NKT cell rates were found in Group 3. CONCLUSIONS: Findings show that zinc and melatonin supplements have led to an increase in the immunity parameters of rats with breast cancer.

Changes in the Serum Levels of Trace Elements Before and After the Operation in Thyroid Cancer Patients.

The present study aims to examine the changes in the serum levels of trace elements before and after the operation in thyroid cancer patients. The study registered 50 individuals, of whom 25 were female and 25 were male. The patients were allocated to four groups: group 1: male thyroid cancer patients group (n = 15), group 2: female thyroid cancer patients group (n = 15), group 3: male control group (n = 10), group 4: female control group (n = 10). The subjects in groups 1 and 2 were the patients who were post-operatively diagnosed with a pathological malignancy in the thyroid tissue samples. Blood samples were collected from all subjects before the operation, immediately after the operation, and on the post-operative day 15. Additionally, thyroid tissue samples were taken from all subjects post-operatively. Some elements in the blood and tissue samples were determined using the atomic emission method. Zinc and selenium levels of groups 1 and 2 in the pre- and post-operative measurements were significantly lower than those in the control groups (p < 0.05), but were higher in the thyroid tissue (p < 0.05). Serum zinc and selenium levels measured in the subjects on the post-operative day 15 were similar to those measured in the controls. Our study show that changes in the serum and thyroid tissue levels of trace elements like zinc and selenium, which play a critical role in thyroid function, might be associated with the pathogenesis of thyroid cancer.

Effects of Chronic and Acute Zinc Supplementation on Myocardial Ischemia-Reperfusion Injury in Rats.

The present study aims to explore the effects of chronic and acute zinc sulfate supplementation on myocardial ischemia-reperfusion injury in rats. The study registered 50 adult male rats which were divided into five groups in equal numbers as follows: group 1, normal control; group 2, sham; group 3, myocardial ischemia reperfusion (My/IR): the group which was fed on a normal diet and in which myocardial I/R was induced; group 4, myocardial ischemia reperfusion + chronic zinc: (5 mg/kg i.p. zinc sulfate for 15 days); and group 5, myocardial ischemia reperfusion + acute zinc: the group which was administered 15 mg/kg i.p. zinc sulfate an hour before the operation and in which myocardial I/R was induced. The collected blood and cardiac tissue samples were analyzed using spectrophotometric method to determine levels of MDA, as an indicator of tissue injury, and GSH, as an indicator of antioxidant activity. The highest plasma and heart tissue MDA levels were measured in group 3 (p < 0.05). Group 5 had lower MDA values than group 3, while group 4 had significantly lower MDA values than groups 3 and 5 (p < 0.05). The highest erythrocyte GSH values were found in group 4 (p < 0.05). Erythrocyte GSH values in group 5 were higher than those in group 3 (p < 0.05). The highest GSH values in heart tissue were measured in group 4 (p < 0.05). The results of the study reveal that the antioxidant activity inhibited by elevated oxidative stress in heart ischemia reperfusion in rats is restored partially by acute zinc administration and markedly by chronic zinc supplementation.

Effects of diurnal and nocturnal strenuous exercise on serum melatonin levels / Efeitos do exercício extenuante diurno e noturno sobre os níveis séricos de melatonina / Efectos del ejercicio extenuante diurno y nocturno en los niveles séricos de la melatonina

ABSTRACT Introduction: There are reports of a possible relationship between melatonin, a hormone secreted by the pineal gland, and exercise. Objective: The present study aims to investigate how diurnal and nocturnal strenuous exercise affects melatonin levels. Methods: The study enrolled 10 healthy sedentary males who did not actively exercise. The subjects had a mean age of 22.20±0.24 years, a mean height of 174.60±2.33 cm, and a mean weight of 69.70±2.42 kg. Two blood samples were collected from the subjects, one at rest, at 10:00 am, and the other immediately after strenuous exercise. Likewise, blood samples were taken from the same group of subjects after 48 hours: at 24:00 hours at rest and immediately after strenuous exercise. Samples were analyzed using the ELISA method to determine the serum melatonin levels (pg/ml). Results: By comparing the values at rest and after exercise, it was found that serum melatonin values remained unchanged with exercise. Serum melatonin values at rest or post-exercise measured at night were higher when compared with those measured during the day (p<0.05). Conclusions: Higher levels of melatonin found in the study appear to result from the increased release of melatonin at night, and not from exercise. The results of this study indicate that strenuous exercise carried out day or night, did not significantly influence serum melatonin levels.

RESUMO Introdução: Há relatos de uma possível relação entre a melatonina, hormônio secretado pela glândula pineal, e exercício. Objetivo: O presente estudo tem como objetivo investigar como o exercício extenuante diurno e noturno afeta os níveis de melatonina. Métodos: O estudo inscreveu 10 homens sedentários saudáveis que não se exercitavam ativamente. Os sujeitos tinham média de idade de 22,20 ± 0,24 anos, estatura média de 174,60 ± 2,33 cm e peso médio de 69,70 ± 2,42 kg. Duas amostras de sangue foram coletadas dos sujeitos, uma em repouso, às 10h00 da manhã e a outra imediatamente após exercício extenuante. Da mesma forma, foram coletadas amostras de sangue do mesmo grupo de sujeitos depois de 48 horas: às 24h00 em repouso e imediatamente após exercício extenuante. As amostras foram analisadas pelo método ELISA para determinar os níveis séricos de melatonina (pg/ml). Resultados: Ao serem comparados os valores de repouso e depois do exercício, verificou-se que os valores séricos de melatonina permaneceram inalterados após exercício. Os valores séricos de melatonina em repouso e pós-exercício, medidos à noite foram mais elevados em comparação com os valores medidos durante o dia (p < 0,05). Conclusões: Os níveis elevados de melatonina encontrados no estudo parecem resultar do aumento da liberação de melatonina à noite, e não do exercício. Os resultados deste estudo indicam que o exercício extenuante realizado durante o dia ou à noite, não influenciou significativamente os níveis séricos de melatonina.

RESUMEN Introducción: Hay reportes de una posible relación entre la melatonina, una hormona secretada por la glándula pineal, y el ejercicio. Objetivo: Este estudio tiene como objetivo investigar cómo el ejercicio extenuante diurno y nocturno afecta a los niveles de melatonina. Métodos: En el estudio participaron 10 hombres sanos sedentarios que no hacían ejercicio de forma activa. Los sujetos tenían una edad promedio de 22,20 ± 0,24 años, altura promedio de 174,60 ± 2,33 cm, y peso promedio de 69,70 ± 2,42 kg. Dos muestras de sangre se obtuvieron de los sujetos, una en reposo, a las 10:00 horas de la mañana y la otra inmediatamente después del ejercicio vigoroso. Igualmente, las muestras de sangre se recogieron del mismo grupo de sujetos después de 48 horas: a las 24:00 horas en reposo e inmediatamente después del ejercicio extenuante. Las muestras se analizaron usando el método ELISA para determinar los niveles de melatonina en suero (pg/ml). Resultados: Mediante la comparación de los valores en reposo y después del ejercicio, se encontró que los valores séricos de melatonina se mantuvieron sin cambios después del ejercicio. Ambos valores de melatonina en reposo y después del ejercicio, medidos por la noche fueron más altos en comparación con los medidos durante el día (p < 0,05). Conclusiones: Los altos niveles de melatonina encontrados en el estudio parecen ser el resultado del aumento de la liberación de melatonina en la noche, y no del ejercicio. Los resultados de este estudio indican que el ejercicio extenuante realizado durante el día o por la noche, no afectó significativamente los niveles de melatonina en suero.

Chronic (3-Weeks) Treatment of Estrogen (17ß-Estradiol) Enhances Working and Reference Memory in Ovariectomized Rats: Role of Acetylcholine.

Recently there has been a growing interest in the effects of estrogen on cognitive functions. In this study, we aimed to examine 17ß-estradiol treatment on working and reference memory in ovariectomized rats. We also examined the changes in the acetylcholine (ACh) levels in the brain areas associated with learning and memory. The study was performed on Sprague-Dawley type 3-month-old female rats. The rats were divided into four groups as control, ovariectomy (OVX), and OVX and estrogen treatment (10 µg/day i.p. 17ß-estradiol) groups for 3 (OVX + E3) and 21 days OVX + E21). The rats were trained on eight arm radial maze task with eight arms baited to assess spatial memory, in addition four arms baited to assess both working and reference memory performances. The electron microscope images of the ACh vesicles in the frontal cortex, temporal cortex and hippocampus areas of the brain which are important regions for learning and memory were screened. Results showed that long term 17ß-estradiol treatment has positive effects on both reference memory and working memory and that ACh vesicles increased in the examined brain areas, especially in hippocampus. Our results suggest that 3 weeks 17ß-estradiol treatment may have an ameliorative effect on the memory through the central cholinergic system.

Pre- and post-estrogen administration in global cerebral ischemia reduces blood-brain barrier breakdown in ovariectomized rats.

The aim of present study was to determine the effect of estrogen treatment on blood-brain barrier permeability in rats with induced global cerebral ischemia. The study included six-month-old female Sprague-Dawley rats which were divided into the following groups: Control-Ischemia-Reperfusion (C + I-R); Ovariectomy-Ischemia-Reperfusion (Ovx + I-R); Ovariectomy + Estrogen + Ischemia-Reperfusion (Ovx + E + I-R); Ovariectomy + Ischemia-Reperfusion + Estrogen (Ovx + I-R + E). Ischemia-reperfusion was induced by clamping two carotid arteries, then opening the clamp. Blood-brain barrier permeability was visualized by Evans Blue extravasation and quantified by spectrophotometry. Our results indicate that following ischemia-reperfusion the BBB permeability is increased in ovariectomized rats (Evans Blue extravasation) compared to the control group in the cortex, thalamus, hippocampus, cerebellum and brain stem, while in the midbrain no significant increase was detected. In contrast, BBB permeability in the groups treated with estrogen, administered either before or after ischemia-reperfusion, was significantly lower than in ovariectomized animals. In conclusion, the increase in BBB permeability resulting from experimentally induced cerebral ischemia was prevented by exogenous estrogen treatment. The study results indicate that estrogen may be used for therapeutic purposes in ischemia-reperfusion.

Serum levels of calcium, selenium, magnesium, phosphorus, chromium, copper and iron--their relation to zinc in rats with induced hypothyroidism.

There is an important relation between thyroid hormones and zinc. Establishment of low zinc levels in hypothyroidism and high levels in hyperthyroidism is a significant proof of this relation. The aim of the present study was to explore changes in serum levels of some elements and their relation to zinc in rats with hypothyroidism. Thirty adult male rats of Sprague-Dawley type were divided into 3 equal groups: group 1, control; group 2, sham-hypothyroidism group supplemented with 10 mg/kg serum physiologic i.p. for 4 weeks; and group 3, hypothyroidism group supplemented with 10 mg/kg propylthiouracil i.p. for 4 weeks. Blood samples were collected from all animals by decapitation and serum calcium, phosphorus, chromium, copper, iron, magnesium, selenium and zinc levels were analyzed using an atomic emission apparatus. Group 3 had lower calcium, selenium and zinc levels, and higher chromium, copper, iron and phosphorus levels (p < 0.01 all) relative to groups 1 and 2. Study parameters did not differ between groups 1 and 2. Results obtained in this study indicate that hypothyroidism leads to changes in serum levels of some elements in rats. These changes may be associated with reduced zinc levels in hypothyroidism.

Effects of exercise and zinc supplementation on cytokine release in young wrestlers.

The present study aims to examine the effect of zinc supplementation on the release of some cytokines in young wrestlers actively involved in wrestling. A total of 40 male subjects of the same age group were included in the study: half were wrestlers and the other half were not involved in sports. The subjects were equally divided into four groups and treated during an 8-week period as follows: group 1, zinc-supplemented athletes; group 2, non-supplemented athletes; group 3, zinc-supplemented sedentary subjects, and group 4, non-supplemented sedentary group. Blood samples were taken from each subject at the beginning and at the end of the study period. The serum tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), and interpheron-γ levels (IFN-γ) were determined using the enzyme-linked immunosorbent assay method. At the beginning of the study, there were no significant differences of the measured parameters between the four study groups. At the end of the study, the levels of TNF-α, IL-2, and IFN-γ were significantly higher in the two zinc-supplemented groups compared to those that did not receive supplementation, regardless of the activity status (p < 0.01).