فهرست مطالب taghi lashkarboluki

Cryopreservation techniques are useful methods for long-term storage of cells and tissues of the reproductive system. The purpose of this study was to investigate the development and survival rate of vitrified preantral follicles compare with those of isolated preantral follicles from vitrified ovaries.
Preantral follicles of 14 to 16 days-old of NMRI mice ovaries were randomly divided into three groups. Group I: preantral follicles derived from fresh ovaries (control). Group II: preantral follicles derived from vitrified ovaries and group 3: vitrified preantral follicles. After thawing, preantral follicles were cultured in α- MEM medium containing 5% FBS, 100 mIU/ml hFSH, 1% ITS and 10 ng/ ml EGF. At the day 12 of culture, ovulation was induced by adding 1.5 IU/ml hCG. The preantral follicle diameter and the rates of survival, antrum formation and developmental stages of released oocytes were evaluated.
The results showed that the survival rate of vitrified preantral follicles was significantly higher than that of isolated preantral follicle from vitrified ovaries. The mean diameter of preantral follicles, the rates of antrum formation and MII stage oocytes in vitrified preantral follicles were significantly higher than those of isolated preantral follicles from vitrified ovaries.
Vitrified preantral follicles were more suitable to develop to mature oocytes in comparison with isolated preantral follicles from vitrified ovaries.

Occurrenceofoxidative stress (OS) following in vitro culture is inescapable. Therefore, the aim of the present study was to determine the efficacy of Coenzyme Q10(CoQ10) supplementation medium on developments and Total Antioxidant Capacity (TAC) of mouse vitrified pre-antral follicles. Fresh and vitrified-warmed isolated preantral follicles from ovaries of 14-16 days-old mice were cultured in supplemented α- MEM medium with or without CoQ10.On the twelfth day of culture period,ovulation was induced by adding 1.5 IU/ml human Chorionic Gonadotropin (hCG). Rates of survival, antrum formation and developmental stages of released oocytes (GV, MI, MII) were evaluated. Separately,total antioxidant capacity (TAC) levels were measured at initial time, 24, 48, 72 and 96 hours of culture periodby ferric reducing/antioxidant power (FRAP) assay. The results showed that the mean diameter and rates of survival, antrum formation, ovulation and MII oocytes of fresh and vitrified-warmed isolated preantral follicles with pretreatment of CoQ10 were significantly higher than those of respective groups without pretreatment ofCoQ10. TAC levels significantly increased up to 96hours in fresh and vitrified-warmed preantral follicles with pre-treatment of CoQ10 compared with thosewhich were cultured without CoQ10. Supplemented culture medium with CoQ10 promotes TAC levels and development of both fresh and vitrified-warmed isolated preantral follicles.

The aim of this study was to investigate the in vitro developmental competence of isolated pre-antral follicles derived from vitrified ovaries in the presence of coenzyme Q10 (CoQ10). Mice pre-antral follicles derived from fresh and vitrified-warmed ovarian tissues were in vitro cultured individually in α-MEM medium supplemented with or without CoQ10, followed by adding human Chorionic Gonadotropin (hCG) to induce ovulation. The follicle development parameters and ovulated oocyte maturationwere assessed.The diameter and development of pre-antral follicles and oocyte maturation rates were significantly higher in CoQ10 pretreatment groups of both vitrified and fresh samples compared to the respective CoQ10free conditions groups. CoQ10 improves the in vitrodevelopment of pre-antral follicles derived from fresh and vitrified –warmed ovaries.

Seizure is an abnormal electrical activity probably due to an imbalance between excitation and inhibition in the brain. Pentylenetetrazol (PTZ) is a chemical convulsive agent abundantly used in laboratory animals. PTZ induces a change in glutamate and GABA in the brain which this study investigates the persistence of this change. In this experimental study, 18 male Wistar rats divided into 3 groups. Three i.v doses of PTZ; 20, 25 and 30 mg/ml were used to determine the effective PTZ dose. Convulsive behaviors were monitored as tonic clonic and myoclonic twitches. Hippocampal glutamate and GABA contents were measured using a biochemical method. Dose of 20 was resulted in long latency to and short lasting TC convulsions with a high volume of injected PTZ solution. On the other hand, dose of 25 and 30 led to short latency and long lasting convulsions with low volume of injecting solution. However there was high rate of mortality (100%) in dose of 30 mg/ml. Hippocampal glutamate content was decreased in zero and 20 min groups while GABA content was decreased only in 20 min group. It is concluded that dose of 25 is the appropriate i.v dose to induce TC convulsions in rats which decreases glutamate and GABA while increases the ratio of glutamate to GABA. Therefore, alteration of glutamate and GABA may be the basis for subsequent seizure induced changes.

Epilepsy is a neural disorder in which abnormal plastic changes during short and long term periods lead to increased excitability of brain tissue. Kindling is an animal model of epileptogenesis which results in changes of synaptic plasticity due to repetitive electrical or chemical sub-convulsive stimulations of the brain. Lateral hypothalamus, as the main niche of orexin neurons with extensive projections, is involved in sleep and wakefulness and so it affects the excitability of the brain. Therefore, we investigated whether lateral hypothalamic area (LHA) inactivation or orexin-A receptor blocking could change convulsive behavior of acute and kindled PTZ treated animals and if glutamate has a role in this regard. Kindling was induced by 40 mg/kg PTZ, every 48 hours up to 13 injections to each rat. Three consecutive stages 4 or 5 of convulsive behavior were used to ensure kindling. Lidocaine was injected stereotaxically to inactivate LHA, unilaterally. SB334867 used for orexin receptor 1 (OX1R) blocking administered in CSF. We demonstrated that LHA inactivation prevented PTZ kindling and hence, excitability evolution. Hippocampal glutamate content was decreased due to LHA inactivation, OX1R antagonist infusion, lidocaine injection and kindled groups. In accordance, OX1R antagonist (SB334867) and lidocaine injection decreased PTZ single dose induced convulsive behavior. While orexin-A i.c.v. infusion increased hippocampal glutamate content, it did not change PTZ induced convulsive intensity. It is concluded that LHA inactivation prevented kindling development probably through orexin receptor antagonism. CSF orexin probably acts as an inhibitory step on convulsive intensity through another unknown process.

The purpose of this study was to investigate the role of oxidative stress in Purkinje cell neurotoxicity ofethanol-treated rat. Male rat pups 4-day-old was used in this study. Ethanol was administered to rat pups at a dose of 6 g/kg from postnatal days (PDs) 4 to 5. Pups were killed 90 min after the second alcohol treatment on PD 5 by decapitation and the brain was immediately removed. The cerebellum was dissected for analyzing the oxidative stress parameters and histological study. The activities of several antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in vermis of cerebellum were assayed. Thiobarbituric acid reactive substances (TBARS) levels were also measured as a marker of lipid peroxidation. Administration of ethanol significantly increased TBARS levels in the cerebellum compared to control pups (P< 0.01). The treated pups with ethanol exhibited a marked decrease in the GPx activity (P< 0.01) whereas, in spite of decrease in the activities of SOD and CAT, when compared to control, there were not significant differences. The spherical cell bodies of Purkinje cells in control rats are aligned nicely between the granular and molecular layers. In ethanol treated pups, Purkinje cells scattered within the Purkinje cell layer and shrinkage of the cell somata is seen.The results of the present work demonstrated that ethanol exposure during the vulnerable window could increase TBARS levels (lipid peroxidation) and decrease GPx levels in pup's cerebellum. Also, the results confirmed ethanol-induced microencephaly, cerebellar Purkinje cell loss. These findings suggest that Purkinje cell loss is, in part through decrease in the activity of GPx and increase of lipid peroxidationin the rat cerebellum.