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Full-Text Articles in Medicine and Health Sciences

Radioprotective Effects Of Melatonin And Thymoquinone On Liver, Parotid Gland, Brain, And Testis Of Rats Exposed To Total Body Irradiation, Mehmet Koç, Çi̇ğdem Damla Deni̇z, Mehmet Aki̇f Eryilmaz, Yilmaz Tezcan, Mehmet Gürbi̇lek Aug 2023

Radioprotective Effects Of Melatonin And Thymoquinone On Liver, Parotid Gland, Brain, And Testis Of Rats Exposed To Total Body Irradiation, Mehmet Koç, Çi̇ğdem Damla Deni̇z, Mehmet Aki̇f Eryilmaz, Yilmaz Tezcan, Mehmet Gürbi̇lek

Turkish Journal of Medical Sciences

Background/aim: This study aimed to investigate thymoquinone (TQ), and melatonin's radioprotective effects on liver, parotid gland, brain, and testis of rats which were exposed to total body irradiation (IR). Materials and methods: Thirty adult Wistar rats were randomly divided into four groups that are Group 1 (control group): total body IR only, Group 2: IR-Melatonin (10 mg/kg), Group 3: IR-TQ (10 mg/kg), and Group 4 (sham group): nothing. Total body IR dose was 6 Gy. Tissue samples were taken 90 min after IR. The measurements of malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were performed in all groups. …


Modulatory Effect Of Resveratrol And Melatonin On Natural Killer Cell Activity And Adrenomedullin In Diabetic Rats, Fati̇h Özçeli̇k, Fati̇h Hacimustafaoğlu, Alpaslan Tanoğlu Jan 2022

Modulatory Effect Of Resveratrol And Melatonin On Natural Killer Cell Activity And Adrenomedullin In Diabetic Rats, Fati̇h Özçeli̇k, Fati̇h Hacimustafaoğlu, Alpaslan Tanoğlu

Turkish Journal of Medical Sciences

Background/aim: Epidemiological evidence suggests that diabetes poses a high risk for many chronic diseases, especially cardiovascular diseases, and cancer by stimulating many inflammatory and immunological pathogenic mediators and affecting natural killer (NK)-cell activity. In this study, the effects of melatonin and resveratrol on IL-6, TNF-alpha, oxidant/antioxidant capacity, NK-cell activity, and mid-regional proadrenomedullin (MR-proADM) levels of diabetic rats were investigated. Materials and methods: In the study, 28 Sprague Dawley rats were randomly divided into the control group (group I) and 3 streptozotocin- induced diabetes mellitus (DM) groups (group II, III, and IV), each group consisting of 7 rats. Five mg/kg/day melatonin …


Melatonin Has Favorable Preventive Effects On Experimental Chronic Pancreatitis Rat Model, Esra Guzel Tanoglu, Alpaslan Tanoğlu, Makbule Çi̇sel Aydin Meri̇çöz, Muhammed Fevzi̇ Esen Jan 2021

Melatonin Has Favorable Preventive Effects On Experimental Chronic Pancreatitis Rat Model, Esra Guzel Tanoglu, Alpaslan Tanoğlu, Makbule Çi̇sel Aydin Meri̇çöz, Muhammed Fevzi̇ Esen

Turkish Journal of Medical Sciences

Background/aim: Currently, there is not any specific treatment for chronic pancreatitis (CP). It was aimed to investigate the effects of melatonin administration on endoplasmic reticulum (ER) stress, oxidative stress, fibrosis, biochemical and histopathological parameters, and Abcc2,Abcc5, and Abcg2 gene levels in an experimental rat CP model. Materials and methods: Forty rats were randomized into five groups: Sham, CP, CP+25 mg/kg melatonin, CP+50 mg/kg melatonin, and CP+placebo. In all rats, except the sham group, a model of chronic pancreatitis was accomplished with intraperitoneal caerulein administration. In treatment groups, melatonin was used as a therapeutic agent. Serum TGF-ß, TNF-α, MDA and GPx …


Impact Of Covid-19 On Serum Melatonin Levels And Sleep Parameters In Children, Özlem Yayici Köken, Pembe Gültutan, Merve Si̇bel Güngören, Gülsüm İclal Bayhan, Deni̇z Yilmaz, Esra Gürkaş, Hami̇t Özyürek, Ayşegül Neşe Çitak Kurt Jan 2021

Impact Of Covid-19 On Serum Melatonin Levels And Sleep Parameters In Children, Özlem Yayici Köken, Pembe Gültutan, Merve Si̇bel Güngören, Gülsüm İclal Bayhan, Deni̇z Yilmaz, Esra Gürkaş, Hami̇t Özyürek, Ayşegül Neşe Çitak Kurt

Turkish Journal of Medical Sciences

Background/aim: This study aimed to analyze the serum melatonin levels and changes in sleep patterns in pediatric patients with coronavirus disease 2019 (COVID-19). Materials and methods: This study was designed as a descriptive, cross-sectional study. Serum melatonin levels and sleep parameters of children with the diagnosis of COVID-19 who had mild and moderate disease (i.e., COVID-19 group) were compared with those of children admitted with non-COVID-19 nonspecific upper respiratory tract infection (i.e., control group). The sleep disturbance scale for children (SDSC) questionnaire was applied to the participants' primary caregivers to analyze their sleep patterns at present and six months before …


Melatonin, Aging, And Covid-19: Could Melatonin Be Beneficial For Covid-19 Treatment In The Elderly?, Güler Öztürk, Kazi̇me Gonca Akbulut, Şevi̇n Güney Jan 2020

Melatonin, Aging, And Covid-19: Could Melatonin Be Beneficial For Covid-19 Treatment In The Elderly?, Güler Öztürk, Kazi̇me Gonca Akbulut, Şevi̇n Güney

Turkish Journal of Medical Sciences

The aim of this review is to summarize current studies on the relationship between melatonin and aging. Nowadays, age-related diseases come into prominence, and identifying age-related changes and developing proper therapeutic approaches are counted as some of the major issues regarding community health. Melatonin is the main hormone of the pineal gland. Melatonin is known to influence many biological processes in the body, including circadian rhythms, the immune system, and neuroendocrine and cardiovascular functions. Melatonin rhythms also reflect the biological process of aging. Aging is an extremely complex and multifactorial process. Melatonin levels decline considerably with aging and its decline …


Melatonin Attenuates Ovarian Ischemia Reperfusion Injury In Rats By Decreasing Oxidative Stress Index And Peroxynitrite, Şenol Kalyoncu, Bülent Yilmaz, Mustafa Demi̇r, Meltem Tuncer, Zehra Bozdağ, Onur Ince, Mehmet Aki̇f Bozdayi, Hasan Ulusal, Seyi̇than Taysi Jan 2020

Melatonin Attenuates Ovarian Ischemia Reperfusion Injury In Rats By Decreasing Oxidative Stress Index And Peroxynitrite, Şenol Kalyoncu, Bülent Yilmaz, Mustafa Demi̇r, Meltem Tuncer, Zehra Bozdağ, Onur Ince, Mehmet Aki̇f Bozdayi, Hasan Ulusal, Seyi̇than Taysi

Turkish Journal of Medical Sciences

Background/aim: To evaluate the protective effect of melatonin on ovarian ischemia reperfusion injury in a rat model. Materials and methods: Forty-eight rats were separated equally into 6 groups. Group 1: sham; Group 2: surgical control with 3-h bilateral ovarian torsion and detorsion; Group 3: intraperitoneal 5% ethanol (1 mL) just after detorsion (as melatonin was dissolved in ethanol); Group 4: 10 mg/kg intraperitoneal melatonin 30 min before 3-h torsion; Group 5:10 mg/kg intraperitoneal melatonin just after detorsion; Group 6:10 mg/kg intraperitoneal melatonin 30 min before torsion and just after detorsion. Both ovaries and blood samples were obtained 7 days after …


Physiological And Pharmacological Roles Of Melatonin In The Pathophysiologicalcomponents Of Cellular Injury After Ischemic Stroke, Ertuğrul Kiliç, Berrak Çağlayan, Mustafa Caglar Beker Jan 2020

Physiological And Pharmacological Roles Of Melatonin In The Pathophysiologicalcomponents Of Cellular Injury After Ischemic Stroke, Ertuğrul Kiliç, Berrak Çağlayan, Mustafa Caglar Beker

Turkish Journal of Medical Sciences

Apart from its metabolic or physiological functions, melatonin has a potent cytoprotective activity in the physiological and pathological conditions. It is synthetized by the pineal gland and released into the blood circulation but particularly cerebrospinal fluid in a circadian manner. It can also easily diffuse through cellular membranes due its small size and lipophilic structure. Its cytoprotective activity has been linked to its potent free radical scavenger activity with the desirable characteristics of a clinically- reliable antioxidant. Melatonin detoxifies oxygen and nitrogen-based free radicals and oxidizing agents, including the highly toxic hydroxyl-and peroxynitrite radicals, initiating cellular damage. However, the cytoprotective …


The Role Of Melatonin In Preventing Ovarian Tissue Damage In Rats Exposed To Magnetic Fields, Zahi̇de Küçük, Uğurkan Erkayiran, Muzaffer Çaydere, Damla Kayalp, Deni̇z Karçaaltincaba Jan 2018

The Role Of Melatonin In Preventing Ovarian Tissue Damage In Rats Exposed To Magnetic Fields, Zahi̇de Küçük, Uğurkan Erkayiran, Muzaffer Çaydere, Damla Kayalp, Deni̇z Karçaaltincaba

Turkish Journal of Medical Sciences

Objectives: We observed the efficacy of melatonin in preventing ovarian tissue damage in rats exposed to magnetic fields. Materials and methods: Forty rats were divided into four treatment groups: Group 1, control group (n = 10); Group 2, melatonin administration only (n = 10); Group 3, magnetic field exposure only (n = 10); Group 4, magnetic field exposure with melatonin administration (n = 10). The magnetic field was applied at a dose of 20 μT for 30 min/day for 10 days. Melatonin was orally administered at a dose of 10 mg/kg. We evaluated follicle count, degree of fibrosis, amount of …


Comparative Efficacy Of Antioxidant Retinol, Melatonin, And Zinc During In Vitro Maturation Of Bovine Oocytes Under Induced Heat Stress, Jafrin Ara Ahmed, Devojyoti Dutta, Nawab Nashiruddullah Jan 2016

Comparative Efficacy Of Antioxidant Retinol, Melatonin, And Zinc During In Vitro Maturation Of Bovine Oocytes Under Induced Heat Stress, Jafrin Ara Ahmed, Devojyoti Dutta, Nawab Nashiruddullah

Turkish Journal of Veterinary & Animal Sciences

Both A and B grade cumulus-oocyte complexes (COCs) aspirated from cattle ovaries at slaughter were matured in vitro under normal (38.5 °C) and elevated temperatures (41 °C). Maturation competence based on cumulus expansion, COC diameter, and nuclear maturation were compared with and without antioxidant supplementation incorporating 7.5 µM retinol, 1 nM melatonin, and 1.5 µg/mL zinc chloride in an oocyte maturation medium. Heat stress significantly reduced cumulus expansion by approximately 20%, while only retinol could bring a significant (P ≤ 0.05) increase. Heat stress also decreased expansion of A (approximately 50%) and B (approximately 40%) grade COC diameter. All antioxidants …


Beneficial Effects Of Melatonin And Bq-123 On The Rat Testis Damage Caused By Cigarette Smoke, Hüseyi̇n Aslan, Hakan Kesi̇ci̇, Zafer İsmai̇l Karaca, Bi̇rsen Özyurt, Ufuk Taş, Fati̇h Eki̇ci̇, Hasan Erdoğan, Fi̇kret Gevrek, Sevi̇l Çayli Jan 2015

Beneficial Effects Of Melatonin And Bq-123 On The Rat Testis Damage Caused By Cigarette Smoke, Hüseyi̇n Aslan, Hakan Kesi̇ci̇, Zafer İsmai̇l Karaca, Bi̇rsen Özyurt, Ufuk Taş, Fati̇h Eki̇ci̇, Hasan Erdoğan, Fi̇kret Gevrek, Sevi̇l Çayli

Turkish Journal of Medical Sciences

Several studies have demonstrated that cigarette smoke has detrimental effects on testicular function. However, it is unknown whether melatonin or BQ-123 has beneficial effects on the rat testis damage caused by cigarette smoke. The aim of the present study was to investigate the beneficial effects of melatonin or BQ-123 on the testicular damage caused by cigarette smoke. Materials and methods: Twenty Wistar rats were randomly divided into 4 equal groups: control group (n = 5), cigarette smoke group (n = 5), melatonin group (n = 5), and BQ-123 group (n = 5). At the end of 4 weeks, all the …


Effects Of Melatonin And Theanine Administration On Pentylenetetrazole-Inducedseizures And Brain Tissue Oxidative Damage In Ovariectomized Rats, Shadi Choopankareh, Farzaneh Vafaee, Mohammad Naser Shafei, Hamid Reza Sadeghnia, Reza Salarinia, Leila Zarepoor, Mahmoud Hosseini Jan 2015

Effects Of Melatonin And Theanine Administration On Pentylenetetrazole-Inducedseizures And Brain Tissue Oxidative Damage In Ovariectomized Rats, Shadi Choopankareh, Farzaneh Vafaee, Mohammad Naser Shafei, Hamid Reza Sadeghnia, Reza Salarinia, Leila Zarepoor, Mahmoud Hosseini

Turkish Journal of Medical Sciences

Background/aim: The effects of coadministration of melatonin and theanine (Mel/Thea) on pentylenetetrazole (PTZ)-induced seizures and brain tissue oxidative damage were investigated in ovariectomized (OVX) and sham-operated rats. Materials and methods: The rats were divided into the following groups: 1) sham, 2) ovariectomized (OVX), 3) sham-PTZ, 4) OVX-PTZ, 5) sham-Mel/Thea-PTZ, and 6) OVX-Mel/Thea-PTZ. Groups 1-4 received saline, while groups 5 and 6 received a combination of Mel/Thea for 6 weeks. All animals except for those in groups 1 and 2 received a single injection of PTZ. Results: The OVX-PTZ group had higher generalized tonic-clonic seizure (GTCS) latency compared to the sham-PTZ …


Plasma 8-Isopgf2? And Serum Melatonin Levels In Patients With Minimal Cognitive Impairment And Alzheimer Disease, Fevzi̇ye Burcu Şi̇ri̇n, Duygu Kumbul Doğuç, Hüseyi̇n Vural, İbrahi̇m Eren, İkbal İnanli, Recep Sütcü, Namik Deli̇baş Jan 2015

Plasma 8-Isopgf2? And Serum Melatonin Levels In Patients With Minimal Cognitive Impairment And Alzheimer Disease, Fevzi̇ye Burcu Şi̇ri̇n, Duygu Kumbul Doğuç, Hüseyi̇n Vural, İbrahi̇m Eren, İkbal İnanli, Recep Sütcü, Namik Deli̇baş

Turkish Journal of Medical Sciences

Background/aim: F2α-isoprostane is accepted as an oxidative stress indicator and melatonin shows neuroprotective effects by antioxidative and antiamyloidogenic influences. By measuring these in patients diagnosed with minimal cognitive impairment (MCI) and Alzheimer-type dementia, we intended to demonstrate whether the measurement of these markers contributes to early diagnosis of Alzheimer disease (AD) in the MCI stage or not. Materials and methods: Three groups (n = 63) were created: the AD group, MCI group, and control group. Serum melatonin levels were measured by radioimmunoassay method, and plasma total 8-isoPGF2α levels were measured by enzyme immunoassay method. Results: Significant differences were observed in …


Immunohistochemical Distribution Of Glutathione Peroxidase And Its Gene Expression Via Rt-Pcr In The Liver Tissue Of Melatonin-Administered Mice, Serap Koral Taşçi, Nurhayat Gülmez Jan 2014

Immunohistochemical Distribution Of Glutathione Peroxidase And Its Gene Expression Via Rt-Pcr In The Liver Tissue Of Melatonin-Administered Mice, Serap Koral Taşçi, Nurhayat Gülmez

Turkish Journal of Veterinary & Animal Sciences

The purpose of this study is to investigate the effect of exogenous administration of melatonin, which is a strong antioxidant agent, on the gene expression of glutathione peroxidase, which is one of the antioxidant enzymes, in the livers of mice and also to examine the immunohistochemical localization of the enzyme. The 24 male Swiss albino mice used in the study were divided into 3 groups: experimental (n = 8), sham (n = 8), and control (n = 8). A 10 mg/kg dose of melatonin was administered intraperitoneally to the experimental group for 4 weeks. Only ethanol and a serum physiological …


Effect Of Melatonin On Contractile Activity In Intraurethrally Instilled E. Coli-Induced Acute Prostatitis Rat Model, Bakhtiyar Huseynov, Nadi̇re Eser, İbrahi̇m Ati̇lla Aridoğan, Şeyda Erdoğan, Yusuf Kenan Dağlioğlu, Hacer Si̇nem Büyüknacar, Fati̇h Köksal, Cemi̇l Göçmen Jan 2013

Effect Of Melatonin On Contractile Activity In Intraurethrally Instilled E. Coli-Induced Acute Prostatitis Rat Model, Bakhtiyar Huseynov, Nadi̇re Eser, İbrahi̇m Ati̇lla Aridoğan, Şeyda Erdoğan, Yusuf Kenan Dağlioğlu, Hacer Si̇nem Büyüknacar, Fati̇h Köksal, Cemi̇l Göçmen

Turkish Journal of Medical Sciences

To investigate whether prostatic inflammation affects the contractile responses of prostate tissue and then whether melatonin has any restorative effect on the contractile responses in a rat model of bacterial prostatitis at early stages. Materials and methods: We evaluated the nerve-evoked, adrenergic agonist-induced or cholinergic agonist-induced contractions of isolated prostate tissue at 24 and 72 h after intraurethrally instilled Escherichia coli-treatment. We also analyzed the histological changes in the prostate. Secondarily, we investigated the effect of melatonin pretreatment (7 days, 10 mg kg^{-1} day^{-1}) on the contractile responses and the histopathologic changes. Results: The degrees of acute inflammatory cell infiltration, …


Does Melatonin Alleviate Cold Preservation Injury Of The Liver?, Ömer Günal, Abdurrahman Coşkun, Ari̇f Aslaner, Ümran Yildirim Jan 2010

Does Melatonin Alleviate Cold Preservation Injury Of The Liver?, Ömer Günal, Abdurrahman Coşkun, Ari̇f Aslaner, Ümran Yildirim

Turkish Journal of Medical Sciences

To investigate the effect of melatonin added to preservation solution on liver cold ischemia. Materials and methods: Twenty male Wistar albino rats were divided equally into groups treated with University of Wisconsin (UW) solution with and without melatonin. The LDH, AST, and ACP activities of the preservation solutions were determined in samples collected at 2, 24, 36, and 48 h. Tissue malondialdehyde and heat shock protein (HSP 70) levels were also measured and a histological examination was performed at 48 h. Results: Melatonin prevented enzyme elevation, induced heat shock protein (HSP 70), and decreased lipid peroxidation effectively in comparison to …


Effects Of Vitamin A And C And Melatonin On 3-Nitrotyrosine Formation In Guinea Pig Heart Under Lipopolysaccharide-Induced Stress, Hali̇l Yaman, Tuncer Çayci, Meli̇k Seyrek, Emi̇n Özgür Akgül, Yasemi̇n Gülcan Kurt, İbrahi̇m Aydin, Hakan Yaren, Erdi̇nç Çakir, Ömer Özcan, Behzat Çi̇men, Nurten Türközkan, Mehmet Kemal Erbi̇l Jan 2010

Effects Of Vitamin A And C And Melatonin On 3-Nitrotyrosine Formation In Guinea Pig Heart Under Lipopolysaccharide-Induced Stress, Hali̇l Yaman, Tuncer Çayci, Meli̇k Seyrek, Emi̇n Özgür Akgül, Yasemi̇n Gülcan Kurt, İbrahi̇m Aydin, Hakan Yaren, Erdi̇nç Çakir, Ömer Özcan, Behzat Çi̇men, Nurten Türközkan, Mehmet Kemal Erbi̇l

Turkish Journal of Medical Sciences

Bacterial lipopolysaccharide (LPS) triggers synthesis of nitric oxide (NO) and superoxide (O_2^{.-}). O_2^{.-} can react with NO to produce the powerful oxidant peroxynitrite (ONOO-). The presence of 3-nitrotyrosine (3-NT) in tissues is often used as a marker of ONOO- production. Vitamin A, vitamin C, and melatonin are potent antioxidant molecules. We sought to clarify this issue by examining the effects of vitamin A (15,000 IU/kg/day), vitamin C (600 mg/kg/day), and melatonin (25 mg/kg) on 3-NT formation in heart tissue in a guinea pig model of LPS-induced endotoxemia. Materials and methods: A total of 75 animals were randomly divided into 5 …


Melatonin Administration Increases Antioxidant Enzymes Activities And Reduces Lipid Peroxidation In The Rainbow Trout (Oncorhynchus Mykiss, Walbaum) Erythrocytes, İlhami̇ Gülçi̇n, Şükrü Beydemi̇r, Olcay Hi̇sar, Ekrem Köksal, Russel J. Reiter Jan 2009

Melatonin Administration Increases Antioxidant Enzymes Activities And Reduces Lipid Peroxidation In The Rainbow Trout (Oncorhynchus Mykiss, Walbaum) Erythrocytes, İlhami̇ Gülçi̇n, Şükrü Beydemi̇r, Olcay Hi̇sar, Ekrem Köksal, Russel J. Reiter

Turkish Journal of Veterinary & Animal Sciences

Effects of melatonin on the levels of antioxidant enzymes including catalase (CAT), peroxidase (POD), glutathione reductase (GRd), and malondialdehyde (MDA), a lipid peroxidation marker, in erythrocytes of rainbow trout (Oncorhynchus mykiss) were investigated. The results showed that melatonin statistically activated the CAT, POD, and GRd activity (P < 0.05). Moreover, MDA levels were significantly decreased as a result of melatonin treatment (P < 0.01).


Antioxidant Effect Of Melatonin In Systemic Circulation Of Rats After Unilateral Testicular Torsion, Fi̇kret Erdemi̇r, Beki̇r Suha Parlaktaş, Hüseyi̇n Özyurt, Özgür Boztepe, Ömer Atiş, Semsetti̇n Şahi̇n Jan 2008

Antioxidant Effect Of Melatonin In Systemic Circulation Of Rats After Unilateral Testicular Torsion, Fi̇kret Erdemi̇r, Beki̇r Suha Parlaktaş, Hüseyi̇n Özyurt, Özgür Boztepe, Ömer Atiş, Semsetti̇n Şahi̇n

Turkish Journal of Medical Sciences

Aim: To investigate the antioxidant effects of melatonin in the systemic circulation of rats after unilateral testicular torsion. Materials and Methods: After the approval of the study by the Local Ethical Committee, 30 male Wistar albino rats, 5.5-6 months old and weighing 250-300 g, were used in the study. The rats were randomly divided into three groups, each consisting of 10 rats. In group 1, the control group, the left testis was excised after sham operation. In group 2, the torsion group, torsion was created by rotating the left testis 720° in clockwise direction and maintained for 2 h. In …


Response Of The Pineal Gland In The Rats Exposed To Three Different Light Spectra Of Short Periods, Eri̇nç Aral, Sema Uslu, Emi̇ne Sunal, Ayla Eker Sariboyaci, İmer Okar, Ertunç Aral Jan 2006

Response Of The Pineal Gland In The Rats Exposed To Three Different Light Spectra Of Short Periods, Eri̇nç Aral, Sema Uslu, Emi̇ne Sunal, Ayla Eker Sariboyaci, İmer Okar, Ertunç Aral

Turkish Journal of Veterinary & Animal Sciences

The pineal gland is a part of the photo-endocrine system. Photon energy is important for the function of this system, and affects the level of nocturnal melatonin. In mammals light-induced suppression of melatonin production is dependent on the intensity and wavelength of the light used. We studied the chronic effects of light wavelengths on the pineal gland in rats after exposure to a short photoperiod using 3 different light spectra with the same irradiance. Male Sprague-Dawley rats were used. The animals were divided into 5 groups. They were exposed 8/16 L:D periods in rooms under automatically regulated light and climate. …


In Vitro Effects Of Melatonin On Hyaluronidase Activity And Sperm Motility In Bull Semen, Sadetti̇n Tanyildizi, Tanzer Bozkurt, Osman Çi̇ftçi̇, Fati̇h Saki̇n Jan 2006

In Vitro Effects Of Melatonin On Hyaluronidase Activity And Sperm Motility In Bull Semen, Sadetti̇n Tanyildizi, Tanzer Bozkurt, Osman Çi̇ftçi̇, Fati̇h Saki̇n

Turkish Journal of Veterinary & Animal Sciences

The effects of melatonin on hyaluronidase activity of semen and spermatozoa motility of Holstein bulls were investigation in vitro. Semen samples were divided into 5 equal parts and incubated (v/v) with melatonin at the doses of 0.5, 1, 2 and 4 mM for 60 min. Percentages of spermatozoa motility, morphological abnormality and hyaluronidase activity of semen were determined at 5, 10, 15, 20, 30 and 60 min during incubation. Results show that melatonin caused a significant (P < 0.001) decrease in the spermatozoa motility, while causing a significant increase in the hyaluronidase activities of the semen. However, there was no significant difference in the percentages of abnormal spermatozoa when compared with control samples. Doses of 0.5, 1, 2 and 4 mM of melatonin in bull semen decreased the percentage of spermatozoa motility in a time- and dose-dependent manner. The mean percentages of abnormal spermatozoa were not affected by melatonin treatment. However, it caused an increased hyaluronidase activity of bull semen. In conclusion, the existence of melatonin in bull semen has a significant effect on fertilization ability by affecting spermatozoa motility and hyaluronidase activity.


The Effects Of Melatonin Hormone On Carbonic Anhydrase Enzyme Activity In Rainbow Trout (Oncorhynchus Mykiss) Erythrocytes In Vitro And In Vivo, Olcay Hi̇sar, Şükrü Beydemi̇r, İlhami̇ Gülçi̇n, Şükri̇ye Aras Hi̇sar, Telat Yanik, Ömer İrfan Küfrevi̇oğlu Jan 2005

The Effects Of Melatonin Hormone On Carbonic Anhydrase Enzyme Activity In Rainbow Trout (Oncorhynchus Mykiss) Erythrocytes In Vitro And In Vivo, Olcay Hi̇sar, Şükrü Beydemi̇r, İlhami̇ Gülçi̇n, Şükri̇ye Aras Hi̇sar, Telat Yanik, Ömer İrfan Küfrevi̇oğlu

Turkish Journal of Veterinary & Animal Sciences

The effects of melatonin hormone on rainbow trout (Oncorhynchus mykiss) erythrocyte carbonic anhydrase enzyme purified by using Sepharose 4B-L tyrosine-sulfanylamide affinity gel chromatography were investigated in vitro and in vivo. Carbonic anhydrase from Oncorhynchus mykiss erythrocytes was purified with a specific activity of ~400 EU/mg protein and ~200-fold in a yield of ~20. Melatonin did not inhibit carbonic anhydrase enzyme in vitro. Carbonic anhydrase activity of the control group was determined as 1597.7 ± 429.0 EU/g hemoglobin in vivo. Carbonic anhydrase activities were measured at 1, 3 and 5 h by following melatonin injection. The corresponding mean activities of melatonin …


The Effects Of Melatonin On 6-Phosphogluconate Dehydrogenase: An In Vitro And In Vivo Study, İlhami̇ Gülçi̇n, Şükrü Beydemi̇r Jan 2004

The Effects Of Melatonin On 6-Phosphogluconate Dehydrogenase: An In Vitro And In Vivo Study, İlhami̇ Gülçi̇n, Şükrü Beydemi̇r

Turkish Journal of Medical Sciences

Melatonin is known to influence a variety of biological processes including circadian rhythms, neuroendocrine, and cardiovascular and immune functions as well as thermoregulation. Melatonin is the chief secretory product of the pineal gland, although it is also produced in other organs. In this study, in vitro effects of melatonin on 6-phosphogluconate dehydrogenase from human erythrocytes and in vivo effects of melatonin on 6-phosphogluconate dehydrogenase from rat (Sprague-Dawley) erythrocytes were studied. Human erythrocyte 6-phosphogluconate dehydrogenase was purified in 3 steps, namely haemolysate preparation, ammonium sulphate fractionation (35-65%) and 2´,5´-ADP Sepharose-4B affinity gel chromatography. 6-Phosphogluconate dehydrogenase was purified with a recovery rate …


Controlling The Breeding Season Using Melatonin And Progestagen In Kıvırcık Ewes, Huri̇ye Horoz Kaya, Güven Kaşikçi, Kemal Ak, Serhat Alkan, Cumhur Sönmez Jan 2003

Controlling The Breeding Season Using Melatonin And Progestagen In Kıvırcık Ewes, Huri̇ye Horoz Kaya, Güven Kaşikçi, Kemal Ak, Serhat Alkan, Cumhur Sönmez

Turkish Journal of Veterinary & Animal Sciences

The effect of melatonin and progestagen sponge administrations separately and together on the reproductive performance at the onset of the breeding season were investigated in Kıvırcık ewes. On June 22, to 40 anoestrous and non-lactating ewes were administrated melatonin (Regulin) implants. On July 14, progestagen (Synchron) sponges were inserted in 20 of these ewes and in 20 other ewes. They were removed 14 days later and on the day of removal the ewes were given 600 I.U. pregnant mare's serum gonadotrophin (PMSG). The other 20 ewes served as controls. Rams were introduced on July 28. The lambing percentages of the …


The Effect Of Levonorgestrel And Melatonin Treatments On Plasma Oxidant-Antioxidant System, And Lipid/Lipoprotein Levels In Female Rats, Kader Köse, Cevad Yazici Jan 2000

The Effect Of Levonorgestrel And Melatonin Treatments On Plasma Oxidant-Antioxidant System, And Lipid/Lipoprotein Levels In Female Rats, Kader Köse, Cevad Yazici

Turkish Journal of Medical Sciences

This study was carried out in order to determine the effects of levonorgestrel (LNG) and progestin derivatives, alone and in combination with melatonin (MEL), on the plasma oxidant-antioxidant system, and also lipid and lipoprotein levels, in the rat model. Female rats were divided into 4 groups according to subcutaneous treatment with LNG (5 mg/kg/day), MEL (25 mg/kg/day) and a LNG-MEL combination (5 mg LNG/25 mg MEL/kg/day) for 5 consecutive days, and a control group. Following the treatment period, malondialdehyde (MDA), conjugated dienes (CD), thiol (SH) and glutathione peroxidase (GPx) values, as the components of the oxidant-antioxidant system, and also triglyceride …