Effects of lipoic acid in an experimentally induced hypertensive and diabetic rat model.

In this study, experimental diabetes and nephrectomy have been applied separately and together in order to investigate the possible therapeutic effects of lipoic acid (LA) on hypertensive and diabetic rat kidneys. Wistar rats were divided into eight groups: control, diabetes mellitus (DM), 5/6 nephrectomy, DM + 5/6 nephrectomy, LA administration, DM + LA treated, 5/6 nephrectomy + LA treated, and DM + 5/6 nephrectomy + LA-treated groups, respectively. Renal damage was evaluated histomorphometrically, ultrastructurally, and biochemically. Our findings supported that diabetes and hypertension together increased the rate of renal injury, and LA had therapeutic effects on hypertensive and diabetic rat kidneys.

The effects of exposure to electromagnetic field on rat myocardium.

Exposure to electromagnetic fields (EMFs) causes increased adverse effects on biological systems. The aim of this study was to investigate the effects of EMF on heart tissue by biochemical and histomorphological evaluations in EMF-exposed adult rats. In this study, 28 male Wistar rats weighing 200-250 g were used. The rats were divided into two groups: sham group (n = 14) and EMF group (n = 14). Rats in sham group were exposed to same conditions as the EMF group except the exposure to EMF. Rats in EMF group were exposed to a 50-Hz EMF of 3 mT for 4 h/day and 7 days/week for 2 months. After 2 months of exposure, rats were killed; the hearts were excised and evaluated. Determination of oxidative stress parameters was performed spectrophotometrically. To detect apoptotic cells, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and caspase-3 immunohistochemistry were performed. In EMF-exposed group, levels of lipid peroxidation significantly increased and activities of superoxide dismutase and glutathione peroxidase decreased compared with sham group. The number of TUNEL-positive cells and caspase-3 immunoreactivity increased in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats. In conclusion, the results show that the exposure to EMF causes oxidative stress, apoptosis and morphologic damage in myocardium of adult rats. The results of our study indicate that EMF-related changes in rat myocardium could be the result of increased oxidative stress. Further studies are needed to demonstrate whether the exposure to EMF can induce adverse effects on myocardium.

Maternal aerobic exercise during pregnancy can increase spatial learning by affecting leptin expression on offspring's early and late period in life depending on gender.

Maternal exercise during pregnancy has been suggested to exert beneficial effects on brain functions of the offspring. Leptin is an adipocytokine which is secreted from adipose tissues and has positive effects on learning, memory, and synaptic plasticity. In this study, pregnant rats were moderately exercised and we observed the effects of this aerobic exercise on their prepubertal and adult offsprings' spatial learning, hippocampal neurogenesis, and expression of leptin. All the pups whose mothers exercised during pregnancy learned the platform earlier and spent longer time in the target quadrant. Their thigmotaxis times were shorter than those measured in the control group. It is shown that hippocampal CA1, CA3 neuron numbers increased in both prepubertal and adult pups, in addition that GD neuron numbers increased in adult pups. Leptin receptor expression significantly increased in the prepubertal male, adult male, and adult female pups. In our study, maternal running during pregnancy resulted in significant increase in the expression of leptin receptor but not in prepubertal female pups, enhanced hippocampal cell survival, and improved learning memory capability in prepubertal and adult rat pups, as compared to the control group. In conclusion, maternal exercise during pregnancy may regulate spatial plasticity in the hippocampus of the offspring by increasing the expression of leptin.

Sustained release spherical agglomerates of polymethacrylates containing mefenamic acid: in vitro release, micromeritic properties and histological studies.

Mefenamic acid (MA) spherical agglomerates (SAs) were prepared with various polymethacrylates having different permeability characteristics (Eudragit RS 100, Eudragit RL 100 and Eudragit L 100) and also with combination of Eudragit RS 100 and Eudragit L 100 in different ratios. SAs were prepared by spherical crystallization method using ethanol/dichloromethane solvent (crystallization) system. The influence of various formulation factors on the encapsulation efficiency, as in vitro drug release, and micromeritic properties was investigated. Target release profile of MA was also drawn. The yields of preparation and the encapsulation efficiencies were high for all formulations. The shape and surface characteristics of SAs were observed by a scanning electron microscope. The particle sizes are in the range of 0.219 ± 0.1 to 0.482 ± 0.25 mm (mean ± confidence interval t(95%)). In addition, histological studies showed that the administration of MA in SAs containing Eudragit RS/L provided a distinct tissue protection in the stomach and duodenum. Differential scanning calorimetry and X-ray diffraction of powder studies showed that MA particles crystallized in the presence of polymethacrylates did not undergo structural modifications.

Design and in vitro, in vivo evaluation of antioxidant bioadhesive gels for burn treatment.

Burn wounds are frequently encountered health problems, which need a new treatment approach especially in terms of good patient compliance. Availability of use of antioxidant agents and bio-adhesive gels in tissue healing can be an alternative as a new approach for wound healing. Antioxidant taurine containing bio-adhesive gels were prepared by using carbopol (CP) 940 and 934. Rheological and texture analyses were carried out on bio-adhesive gels for in vitro characterization. Wound model on Wistar rats was used to evaluate the in vivo evaluation of gels. Rheological and texture analyses showed that a carbopol bioadhesive gel has acceptable topically use dosage characteristics and in combination with Taurine it presented a successful wound healing effect via antioxidant parameters. In conclusion, bio-adhesive CP 940 (2%) gel containing 50 mM taurine could be promising in the treatment of burns by balancing oxidative stress.

Therapeutic effects of melatonin on an ovalbumin-induced allergic rhinitis model in rats.

OBJECTIVE: We aimed to investigate the therapeutic effects of melatonin in an experimental AR model. METHODS: Thirty-two Wistar rats were randomised into four groups (n = 8 each). The experimental AR model was established in the saline (SF), ethanol, and melatonin groups via intraperitoneal (i.p.) injections and intranasal application of ovalbumin. The SF, ethanol, and melatonin groups received daily i.p. saline, 2% ethanol dissolved in saline, and 10 mg/kg melatonin dissolved in 2% ethanol and saline. The control group received the same amount of i.p. and intranasal saline. Total nasal symptom scores were recorded in all rats on days 1 (baseline), 15, 20, 25, and 30. Serum ovalbumin-specific IgE, IL-13, and melatonin levels were measured on days 1 (baseline), 15, and 30. The nasal mucosa of all rats was scored histopathologically. RESULTS: The total nasal symptom scores and serum ovalbumin-specific IgE values of the SF, ethanol, and melatonin groups were significantly higher on day 15 than those of the control group. On day 30, the scores and serum ovalbumin-specific IgE values of the melatonin group were similar to those of the control, whereas the SF and ethanol groups had statistically higher scores. The histological scores of the SF and ethanol groups were significantly higher than those of the control and melatonin groups, but no significant difference was found between the melatonin and control groups. CONCLUSION: Melatonin reduced total nasal symptom scores and serum ovalbumin-specific IgE levels and improved histological inflammation parameters in the ovalbumin-induced rat experimental AR model.

The effects of selenium against cerebral ischemia-reperfusion injury in rats.

It is known that the brain tissue is extremely sensitive to ischemia-reperfusion (IR) injury and therefore, brain ischemia and consecutive reperfusion result in neural damage and apoptosis. The proinflammatory cytokines such as tumor necrosis factor alfa (TNF-alpha) and interleukin-1 beta (IL-1beta) are produced during neurological disorders including cerebral ischemia. On the other hand, nerve growth factor (NGF), which is essential for the differentiation, survival and functions of neuronal cells in the central nervous system, regulate neuronal development through cell survival and cell death signaling. In the present study, we aimed to investigate the effect of selenium (Se) on prefrontal cortex and hippocampal damage in rats subjected to cerebral IR injury. Selenium was injected intraperitoneally at the doses of 0.625 mg/(kg day) after induction of IR injury. Prefrontal cortex and hippocampal damage was examined by cresyl-violet staining. Apostain and caspase-3 immune staining were used to detect apoptosis. TNF-alpha, IL-1beta and NGF levels were also evaluated. Histopathological evaluation showed that treatment with selenium after ischemia significantly attenuated IR-induced neuronal death in prefrontal cortex and hippocampal CA1 regions of rats. Apoptotic cells stained with apostain and caspase-3 were significantly decreased in treatment group when compared with the IR group. Additionally, treatment with selenium decreased the TNF-alpha and IL-1beta levels and increased the NGF levels in prefrontal cortex and hippocampal tissue of animals subjected to IR. The present results suggest that selenium is potentially a beneficial agent in treating IR-induced brain injury in rats.

Protective effects of deprenyl in transient cerebral ischemia in rats.

Cerebral ischemia leads to neuronal damage in the hippocampus and cognitive decline. Reactive oxygen species play an important role in the neuronal loss after cerebral ischemia and reperfusion injury. Deprenyl, an irreversible monoamine-oxidase B inhibitor, has antioxidant and neuroprotective effects against reactive oxygen species. In the present study, the effect of deprenyl on spatial memory impairment, oxidative stress and apoptotic neuronal cell death following transient cerebral ischemia in rats was investigated. Transient ischemia was induced by occlusion of left common carotid artery of rats for 30 min and reperfusion for 24 h or 1 week. Rats received intraperitoneal injection of 1 mg/kg deprenyl (n = 24) or equal volume of saline (n = 24) for 14 days before the experiment. Deprenyl treatment attenuated spatial memory deficits following ischemia-reperfusion as measured by the Morris water maze task. Deprenyl treatment elicited a significant decrease in lipid peroxidation and increase in superoxide dismutase activities in ischemic rat brains. The number of TUNEL-positive cells decreased significantly in deprenyl-treated group when compared with the control group. The results show that deprenyl reduces the ischemia-induced oxidative stress and thus prevents spatial memory deficits and apoptotic neuronal cell death when it is administered before ischemia-reperfusion.

A comparative histological study of alginate beads as a promising controlled release delivery for mefenamic acid.

The new mefenamic acid-alginate bead formulation prepared by ionotropic gelation method using 3 x 2(2) factorial design has shown adequate controlled release properties in vitro. In the present study, the irritation effects of mefenamic acid (MA), a prominent non-steroidal anti-inflammatory (NSAI) drug, were evaluated on rat gastric and duodenal mucosa when suspended in 0.5% (w/v) sodiumcarboxymethylcellulose (NaCMC) solution and loaded in alginate beads. Wistar albino rats weighing 200 +/- 50 g were used during in vivo animal studies. In this work, biodegradable controlled release MA beads and free MA were evaluated according to the degree of gastric or duodenal damage following oral administration in rats. The gastric and duodenal mucosa was examined for any haemorrhagic changes. Formulation code A10 showing both Case II transport and zero order drug release and t(50) % value of 5.22 h was chosen for in vivo animal studies. For in vivo trials, free MA (100 mgkg(-1)), blank and MA (100 mgkg(-1)) loaded alginate beads (formulation code A10) were suspended in 0.5% (w/v) NaCMC solution and each group was given to six rats orally by gavage. NaCMC solution was used as a control in experimental studies. In vivo data showed that the administration of MA in alginate beads prevented the gastric lesions.

Neuroprotective effects of selenium and ginkgo biloba extract (EGb761) against ischemia and reperfusion injury in rat brain.

OBJECTIVES: To determine the neuroprotective effects of Ginkgo biloba extract (EGb761) and Selenium (Se), and the combination of these agents on ischemia/reperfusion (I/R) injury in a rat model of transient global cerebral I/R. METHODS: This experimental study took place in the Animal Research Laboratory at Dokuz Eylul University, Izmir, Turkey in the year 2006. Fifty rats were subjected to cerebral I/R induced by right carotid artery occlusion technique for a duration of 45 minutes, and then were treated with EGb761 (50 mg/kg/day, ip) and Se (0.625 mg/kg, ip), alone or in combination for 14 days after surgery. Superoxide dismutase, and glutathione peroxidase activities were measured in the hippocampal tissues from 25 animals. Histopathological examinations were also carried out under light and electron microscopy from the rest of animals. RESULTS: The results suggest that EGb761 has a potent neuroprotective effect against cerebral I/R induced injury in rat brain that is comparable with that of Se. However, the combined use of EGb761 and Se does not further protect from neuronal injury when compared with the use of both agents alone. DISCUSSION: Our results suggest that administration of EGb761, Se and its combination with EGb761 have significant neuroprotective effects on I/R injury in rats via suppression of oxidative stress.

Suppression of apoptosis and oxidative stress by deprenyl and estradiol in aged rat liver.

Aging is accompanied by significant structural and functional transformations of all organs and systems. Age-associated increase in apoptotic behavior may cause disease. Older cells are more susceptible to endogenous oxidative damage, and oxidative stress is a potent inducer of apoptosis. Deprenyl is an irreversible monoamine-oxidase B inhibitor which has anti-oxidant, anti-apoptotic and neuroprotective effects. Estrogen is also a neuroprotective and anti-oxidant hormone. The objectives of this study were to determine whether the anti-oxidative effects of deprenyl can suppress apoptotic activity, with or without estradiol, in aged female rat livers. In this study, ovariectomized female Wistar albino rats were divided into six groups as follows; young (3 months old) saline-treated control, aged (24 months old) saline-treated control, aged deprenyl treated, aged estradiol treated, aged deprenyl plus estradiol treated and aged sham controls. All rats except for the sham group were treated for 21 days. Determination of oxidative stress parameters was performed spectrophotometrically. To detect apoptotic cells, TUNEL staining was performed. The results were analyzed by one-way ANOVA post hoc Bonferroni test. Deprenyl and estradiol administration, alone or in combination, decreased significantly the levels of lipid peroxidation and increased superoxide dismutase activity in the liver relative to aged control and sham rats (P<0.05). The number of TUNEL positive cells decreased significantly in deprenyl and estradiol-treated rats compared with aged control and sham rats. The results indicate that deprenyl treatment alone, or in combination with estradiol, may modulate age-related apoptotic changes in rat liver by decreasing oxidative stress.

Protective effect of melatonin against maternal deprivation-induced acute hippocampal damage in infant rats.

It is known that maternal deprivation induces hippocampal damage in the developing brains. In the present study, we examined the effects of melatonin on maternal deprivation-induced hippocampal damage both during and after stress-hyporesponsive period (SHRP). Hippocampal damage was examined by cresyl violet staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. The results showed that a single episode of maternal deprivation for 24 h at post-SHRP induced neuronal loss in hippocampus regions of the brain in the infant rats, while it did not influence hippocampal neurons in SHRP. Melatonin prevented maternal deprivation-induced hippocampal damage in the infant rats at post-SHRP. These results suggest that melatonin is a potentially beneficial agent to improve the neurobehavioral outcomes of maternal deprivation in later developmental period.

Development, characterization, and in vivo assessment of mucoadhesive nanoparticles containing fluconazole for the local treatment of oral candidiasis.

This study aimed to develop a suitable buccal mucoadhesive nanoparticle (NP) formulation containing fluconazole for the local treatment of oral candidiasis. The suitability of the prepared formulations was assessed by means of particle size (PS), polydispersity index, and zeta potential measurements, morphology analysis, mucoadhesion studies, drug entrapment efficiency (EE), in vitro drug release, and stability studies. Based on the optimum NP formulation, ex vivo drug diffusion and in vitro cytotoxicity studies were performed. Besides, evaluation of the antifungal effect of the optimum formulation was evaluated using agar diffusion method, fungicidal activity-related in vitro release study, and time-dependent fungicidal activity. The effect of the optimum NP formulation on the healing of oral candidiasis was investigated in an animal model, which was employed for the first time in this study. The zeta potential, mucoadhesion, and in vitro drug release studies of various NP formulations revealed that chitosan-coated NP formulation containing EUDRAGIT(®) RS 2.5% had superior properties than other formulations. Concerning the stability study of the selected formulation, the formulation was found to be stable for 6 months. During the ex vivo drug diffusion study, no drug was found in receptor phase, and this is an indication of local effect. The in vitro antifungal activity studies showed the in vitro efficacy of the NP against Candida albicans for an extended period. Also, the formulation had no cytotoxic effect at the tested concentration. For the in vivo experiments, infected rabbits were successfully treated with local administration of the optimum NP formulation once a day. This study has shown that the mucoadhesive NP formulation containing fluconazole is a promising candidate with once-a-day application for the local treatment of oral candidiasis.

Age-dependent effects of maternal deprivation on oxidative stress in infant rat brain.

Developing brain is much more sensitive to all kind of stressors than the developed brain. Early maternal deprivation causes some behavioural and physiological effects on rats. After the birth, there is no endocrinological response to stressors between post-natal 4 and 14th days, which is called stress-hyporesponsive period (SHRP) in rats. This hypo-responsiveness is time- and stressor-specific, as some more severe stressors have been shown to induce a stress response. The present study examined the effects of maternal deprivation on oxidative stress in the hippocampus, prefrontal cortex (PFC) and striatum regions of the brain both during and after SHRP of the infant rats. The results showed that maternal deprivation in SHRP increased antioxidant enzyme activities and reduced lipid peroxidation in infant rat brain. However, by the termination of SHRP, maternal deprivation reduced enzyme activities and increased lipid peroxidation. The results indicated that infant brain might be protected in SHRP from maternal deprivation-induced oxidative stress.

Effects of topical intranasal doxycycline treatment in the rat allergic rhinitis model.

OBJECTIVES: Allergic rhinitis (AR) is a chronic upper respiratory tract disease that inflames the mucous membranes of the nose and occurs when circulating inflammatory cells including eosinophils and basophils migrate to and accumulate in the inflammation area by passing through the interstitium and capillary walls. To pass through these barriers, the inflammatory cells degrade extracellular matrix proteins. Matrix metalloproteinases (MMPs) released by inflammatory cells mediate the degradation of these proteins. MMPs have synthetic inhibitors and doxycycline, a tetracycline antibiotic, inhibits MMPs. This study investigated the efficiency of intranasal doxycycline in decreasing the symptoms and inflammatory cell infiltration in an animal model of AR. METHODS: AR was created in female Wistar rats by repeated intranasal challenge with ovalbumin by intraperitoneal injection. For 15 days, topical intranasal doxycycline was administered one hour before ovalbumin administration. Following intranasal administration, nasal symptoms were scored and the nasal mucosae of all rats were evaluated histopathologically. To investigate tissue changes, hematoxyline-eosin and Alcian blue/periodic acid Schiff stains were used. As well, cilia loss, goblet cell changes, vascular congestion, vascular proliferation, inflammatory cell infiltration, eosinophil infiltration and the degree of hypertrophy in chondrocytes were evaluated with light microscopy. RESULTS: Typical symptoms of AR were decreased by intranasal doxycycline administration. These effects were stable after repeated intranasal ovalbumin administration. Histological evaluation of doxycycline treated rats did not reveal typical inflammatory changes associated with AR. CONCLUSION: MMPs may have crucial functions in AR and topical intranasal doxycycline, which decreases inflammatory cell infiltration, may offer an alternative therapy for AR.

Neuroprotective effect of erythropoietin on nandrolone decanoate-induced brain injury in rats.

Anabolic-androgenic steroids (AAS) are used in the medical treatment of many disorders. Erythropoietin (EPO) is a hematopoietic cytokine that has anti-apoptotic, anti-oxidative, and anti-inflammatory effects. The aim of the present study is to investigate the neuroprotective effects of EPO in the hippocampus, parietal cortex and prefrontal cortex, in brain damage due to nandrolone decanoate. 35 Wistar male rats were randomly divided into: (1) control group, (2) sham group, (3) nandrolone decanoate group (ND, intramuscular, 10 mg/(kg week), 8 weeks), (4) ND+low dose EPO treated group (ND+L-EPO) and (5) ND+high dose EPO treated group (ND+H-EPO). EPO was administrated by intraperitoneal injection at a dose of 100 U/(kg day) for L-EPO treatment and at a dose of 500 U/(kg day) for H-EPO treatment during 8 weeks. The number of neurons of CA1, CA2, CA3 and dentate gyrus of hippocampus, parietal cortex and prefrontal cortex were significantly less in the ND group compared with the control group. Treatment with H-EPO significantly preserved the number of neurons in hippocampus when compared with ND administrated. Besides, H-EPO treatment decreased the number of TUNEL-positive and active caspase-3 positive cells and MDA levels and increased GPx levels when compared to ND group. In conclusion, abuse of AAS causes reduction in the number of neurons in hippocampus, parietal cortex and prefrontal cortex regions and increases oxidative damage and therefore H-EPO may be useful as a neuroprotective agent in brain injury.

Influence of uracil on bacterial translocation in an intestinal obstruction model in rats.

INTRODUCTION: Bacterial translocation occurs when intestinal mucosa and the intestinal wall lose their barrier properties against bacteria such as in the case of intestinal obstruction. Enteral nutrition with immunonutrients strengthens the immune system and thickens the intestinal barrier thus preventing bacterial translocation. AIM: The purpose of this study is to investigate the effect of uracil which is an immunonutrient on bacterial translocation using rats with intestinal obstruction as a model. METHODS: Wistar albino rats were divided into three groups. The control group was fed with standard chow diet, while the other two groups were fed with uracil-supplemented chow diet. The rats were fed with these diets for seven days. And the end of the feeding period all groups were submitted intestinal obstruction and injected with (99m)Tc labeled Escherichia coli into the rats' terminal ileum under anesthetic. The rats were sacrificed 24 h later. Their blood, mesenteric lymph nodes (MLN), liver, spleen, lung and ileum were removed to determine level of radioactivity. RESULTS: When compared with the control group it was determined that uracil supplementation reduced the level of bacterial translocation. CONCLUSION: Uracil may be used in the prevention of bacterial translocation in cases of intestinal obstruction because it strengthens the intestinal barrier and the immune system. However, more studies are needed to clearly explain the mechanism behind uracil's beneficial role here.

A new approach to the treatment of recurrent aphthous stomatitis with bioadhesive gels containing cyclosporine A solid lipid nanoparticles: in vivo/in vitro examinations.

AIM: To develop a suitable buccal bioadhesive gel formulation containing cyclosporine A solid lipid nanoparticles (CsA SLNs) for the treatment of recurrent aphthous stomatitis. METHODS: The suitability of the prepared formulations for buccal application was assessed by means of rheological studies, textural profile analysis, and ex vivo drug-release studies. Plastic flows, typical gel-like spectra, and suitable mechanical properties were obtained from prepared formulations. The retention time was explored in in vivo distribution studies and the effect of the gel containing CsA SLNs on the healing of oral mucosal ulceration was investigated in an animal model. In vivo distribution studies are a very important indicator of the retention time of formulations at the application site. RESULTS: Distribution studies showed that 64.76% ± 8.35% of the formulation coded "F8+SLN" remained on the buccal mucosa 6 hours after application. For the second part of the in vivo experiments, 36 rabbits were separated into three groups: the first group was treated with the gel formulation without the active agent; the second group with the gel formulation containing CsA SLNs; and the third group, used as the control group, received no treatment. Wound healing was established by scoring of the rate of wound healing on Days 3, 6, 9, and 12. Histological observations were made on the same days as the scoring studies. The bioadhesive gel formulation that included CsA SLNs increased the rate of mucosal repair significantly. CONCLUSION: This study has shown that the bioadhesive gel formulation containing CsA SLNs reported here is a promising candidate for the topical treatment of recurrent aphthous stomatitis.

The effects of prenatal and neonatal exposure to electromagnetic fields on infant rat myocardium.

INTRODUCTION: Electromagnetic fields (EMF) have adverse effects as a result of widespread use of electromagnetic energy on biological systems. The aim of this study was to investigate the effects of prenatal exposure to EMF on rat myocardium by biochemical and histopathological evaluations. MATERIAL AND METHODS: In this study, 10 pregnant Wistar rats were used. Half of the pregnant rats were exposed to EMF of 3 mT, and the other half to sham conditions during gestation. After parturition, rat pups in the 5 EMF-exposed litters from birth until postnatal day 20 were exposed to EMF of 3 mT for 4 h/day (EMF-exposed group, n = 30). Rat pups in sham litters from birth until postnatal day 20 were exposed to sham conditions (sham group, n= 20). RESULTS: In the EMF-exposed group, lipid peroxidation levels significantly increased compared to sham. Superoxide dismutase activities decreased significantly in the EMF-exposed group compared to sham. TUNEL staining showed that the number of TUNEL-positive cells increased significantly in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats. CONCLUSIONS: In conclusion, the results show that prenatal exposure to EMF causes oxidative stress, apoptosis and morphological pathology in myocardium of rat pups. The results of our study indicate a probable role of free radicals in the adverse effects of prenatal exposure to EMF. Further studies are needed to demonstrate whether the EMF exposure can induce adverse effects on the myocardium.

The protective effects of carnosine and melatonin in ischemia-reperfusion injury in the rat liver.

The reperfusion following liver ischemia results in hepatocyte damage and apoptosis. The aim of this study was to investigate the effects of two antioxidant agents, carnosine and melatonin, in rat liver ischemia-reperfusion injury. Five study groups were formed; I. sham, II. ischemia-reperfusion, III. ischemia-reperfusion+melatonin, IV. ischemia-reperfusion+carnosine, V. ischemia-reperfusion+melatonin+carnosine. Then 250 mg/kg carnosine and 10 mg/kg melatonin were administered intraperitoneally 30 min before ischemia and immediately after the reperfusion. Sinusoidal dilatation, congestion and neutrophil infiltration were observed in the ischemia-reperfusion group while these symptoms were less pronounced in the treatment groups. Alanine aminotransferase, aspartate aminotransferase and myeloperoxidase levels were increased in the ischemia-reperfusion group while they were lowered in the treatment groups. Glutathione level was low in the ischemia-reperfusion group while it tended to increase in the ischemia-reperfusion+carnosine administered and ischemia-reperfusion+carnosine+melatonin administered groups. There was an increase in the number of apoptotic cells in the ischemia-reperfusion group while this number was lowered in the treatment groups. Carnosine was more effective than melatonin in the reversal of structural and biochemical alterations that resulted from ischemia-reperfusion injury. The administration of melatonin and carnosine together yielded better outcomes compared to the sole administration of each agent.