Relationship of ozone application and time in rats with hypoxic-ischemic brain injury.

BACKGROUND: Despite the important advances in pregnancy and newborn follow-up, hypoxic-ischemic encephalopathy is still one of the prominent causes of newborn mortality and disability worldwide, and there is no sufficiently effective treatment for it yet. This study aimed to investigate whether the ozone injection, administered in a single-dose as a preconditioning agent before the hypoxia and in single and repeated doses on different days following the hypoxia, would affect the spatial memory performance of the rats in the Morris water maze test or on their apoptotic cell numbers. METHODS: The study consisted of 102 seven-day-old male Wistar baby rats randomly divided into five groups. Rats in all groups were induced with hypoxic-ischemic brain injury (HIBI) except for the Sham group, and 1.2 mg/kg ozone was administered intraperitoneally. For the apoptosis evaluation, eight rats from each of the first four groups were decapitated by cervical dislocation. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay was used for immunohistochemical quantification of apoptosis in the excised brains. Blood malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured in the blood samples collected through cardiac puncture. Fourteen-week-old rats underwent the Morris water maze test to test their long-term spatial memory. RESULTS: On apoptotic quantification in the right hemisphere using the TUNEL assay, the numbers of apoptotic neurons in the ozone preconditioning group (Group 3) and the group given ozone on the day of hypoxia (Group 4) were found to be significantly higher than the Sham group (Group 1), but significantly lower than the non-treatment group (Group 2) (p <0.001; p <0.001, respectively). Group 3 rats had the highest mean MDA level and SOD activity. Considering the platform finding times in the first four days of the tests, Group 4 had the shortest times after Group 1; and on Day 4, Group 4 found the platforms significantly sooner than Groups 2, 3, and 5 (p <0.001). Comparison of Groups 1 and 4 revealed significantly shorter times for Group 1 for each day except for Day 2. CONCLUSIONS: Other studies have shown that controlled application of ozone would result in oxidative preconditioning and reduce the damage induced by reactive oxygen species through enabling adaptation to oxidative stress. Our study obtained remarkable and encouraging findings for ozone administration in HIBI by examining Group 4's performance in the first four days and the difference in its platform finding times between Day 1 and Day 4. HIPPOKRATIA 2021, 25 (2):56-62.

The efficacy of ozone therapy in neonatal rats with hypoxic ischemic brain injury.

OBJECTIVES: This study is aimed to determine the effect of ozone therapy in neonatal rats with experimentally induced hypoxic ischemic brain injury (HIBI). METHODS: The study included 7-d-old male Wistar rats that were randomized to the sham, control, ozone 1, and ozone 2 groups. All rats except those in the sham group were kept in a hypoxia chamber, and then the rats in the control group were given 0.5 mL of saline. Those in the ozone 1 group were given ozone 1 mg kg-1 intraperitoneally, and those in the ozone 2 group were given ozone 2 mg kg-1 intraperitoneally. RESULTS: There were significantly fewer apoptotic neurons in the right hemispheres of the rats in the ozone 1 and ozone 2 groups than in the control group (p < 0.001 and p < 0.001, respectively). There were significantly fewer apoptotic neurons in the right hemispheres of the rats in the ozone 2 group than in the ozone 1 group (p < 0.001). Morris Water Maze (MWM) test results were similar in the ozone 2 and sham groups. CONCLUSIONS: The present study's findings show that ozone therapy reduced neuronal apoptosis and improved cognitive function in neonatal rats with experimentally induced HIBI (Tab. 2, Ref. 30).

Is levetiracetam neuroprotective in neonatal rats with hypoxic ischemic brain injury?

BACKGROUND: The aim of this study was to determine if levetiracetam (LEV) is neuroprotective in neonatal rats with hypoxic-ischemic brain injury (HIBI). METHODS: The study included 7-d-old male Wistar rats that were randomly divided into the LEV400, LEV800, control, and sham groups. All the rats, except those in the sham group, underwent ligation of the carotid artery and were then kept in a hypoxic chamber containing 8% oxygen for 2 h. At the end of the hypoxic period the rats in the control group were administered saline solution 0.5 mL, the rats in the LEV400 group were administered LEV 400 mg.kg-1, and rats in the LEV800 group were administered LEV 800 mg.kg-1 via the intraperitoneal route. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) method was used to evaluate neuronal apoptosis in the rats. The Morris Water Maze (MWM) test was performed at age 14 weeks in order to evaluate cognitive function. RESULTS: The number of apoptotic neurons in the right hemispheres was significantly lower in the sham, LEV400, and LEV800 groups than in the control group (p < 0.001, p < 0.001, and p < 0.001, respectively). In addition, the number of apoptotic neurons in the right hemispheres was significantly lower in the LEV800 group than in the LEV400 group (p = 0.001). Platform finding time (PFT) during MWM testing was significantly shorter in the sham and LEV800 groups on d 4 than on d 1 (p = 0.001 and p = 0.006, respectively); however, PFT did not significantly change between d 1 and d 4 in the control or LEV400 groups (p = 0.91 and p = 0.096, respectively). CONCLUSION: Based on the present findings, LEV exhibited a dose-dependent neuroprotective effect in neonatal rats with HIBI (Ref. 27).

The impact of acute dynamic exercise on intraocular pressure: role of the beta 2-adrenergic receptor polymorphism.

Effects of mutations in the beta 2-adrenergic receptor (beta 2AR) gene on intraocular pressure (IOP), in response to acute dynamic exercise, were investigated in 19 healthy males (age 22.6 +/- 2.8 years). Intraocular pressures were measured pre- and post-exercise. Weight, height, body mass index, and maximal oxygen (VO2max) uptake were recorded and subjects were genotyped for Arg16Gly, Gln27Glu and Thr164Ile mutations of the beta 2AR gene. Post-exercise, reductions in mean IOP values were found in 16 subjects with the Gly16Gly and Arg16Gly genotypes, but these values remained low in the eight patients with the Gly16Gly genotype 3 h post-exercise, whereas they returned to baseline within 1 h in the eight subjects with the Arg16Gly genotype. beta 2AR stimulation during exercise could be an important regulator of IOP response and determining beta 2AR polymorphisms may improve understanding of pathogenesis and treatment selection in ophthalmic diseases, e.g. glaucoma.

The relation between event related potential and working memory in healthy subjects.

In numerous investigations the P300-component of the event related potential has proved a valid indicator of memory activities. The present study explores the amplitude and latency of the components of event-related potential regarding short-term memory task. Event related potentials, elicited by auditory stimuli, were recorded in 40 healthy subjects. For evaluating short term memory capacity of a subject, software in Delphi for Windows language was written. Algorithm of the software was the presentation of randomly selected four different digits for 4 seconds, removing it and waiting for subject's response, adding one digit, if response was true, otherwise decreased by one. After 20 trials, mean of recall time for true answers was computed. The subjects with high recall time showed prolonged latency of P300. A positive correlation was found between P300 latency and recall time. No correlation was found between N1, P2 and N2 latency or amplitude and recall time. These results suggest that memory problems are well correlated with the abnormalities of P300.

The effect of direction on saccadic eye movement parameters.

The present study obtained saccadic eye movements from 25 right-handed normal subjects (aged 18-35 yr, mean 22.4 yr) to examine the effects of saccade direction on saccadic parameters (latency, duration and average velocity). Binocular saccadic eye movements were recorded with a direct-current electrooculographic system, and analysis was performed on a laboratory digital computer. The LED target positions were randomly selected 10, 15, 20, 25 and 30 degrees to the left or right of the fixation points. In general, the mean values of the saccadic parameters over large saccade angles were in agreement with those previously reported. There were no significant differences between saccades directed to the right and to the left.

Slow cortical potential shifts modulate P300 amplitude and topography in humans.

Effects of the spontaneous slow cortical potential (SCP) shifts of the electroencephalogram (EEG) on the P300 response were investigated on ten healthy volunteers. P300 responses were recorded using an auditory oddball paradigm, where target stimuli were presented regularly after every four standard stimuli. Single event-related potential (ERP) sweeps exhibiting negative or positive SCP shifts were averaged separately. The P300 amplitude was significantly larger during negative SCP shifts. Furthermore, the topographies of P200 and P300 waves obtained during negative and positive SCP shifts showed significant differences. The results indicate that the SCP shifts in single ERP sweeps, which are considered to be correlated with the arousal or basic activity level of the cortex, explain at least part of the inter-trial variability of P300 response.

Effect of nicotine on swimming exercise in rats.

In this study, endurance time in swimming exercise was evaluated in rats. Subcutaneous (S.C.) injection of nicotine decreased the endurance time in swimming exercise significantly, in a dose-dependent manner compared to the control group. At the dose of 0.125 mg/kg nicotine, the endurance time in swimming exercise remained unchanged, while at the doses of 0.25 and 0.375 mg/kg, it decreased significantly (p < 0.05 and p < 0.01, respectively). This effect of nicotine was antagonized by pretreatment with hexamethonium 5 mg/kg S.C. These results suggest that nicotine may limit the physical performance.

Influence of calcium removal from bath solution on isolated rat duodenum contractions.

In this study whether extracellular Ca++ is essential to produce an increase of tension of isolated rat duodenum by ACh, 5-HT, AVP and KCl-, was examined. KCl- and AVP-evoked contractions were almost totally prevented by Ca++ removal from bath solution. The increase of tension of isolated duodenum caused by ACh or 5-HT was totally prevented after adding nifedipine, a Ca++ channel blocker, into Ca free solution. Our results suggest that ACh or 5-HT utilizes intracellular as well as extracellular sources of Ca++ to produce contraction in rat duodenum, whereas AVP-or KCl evoked contraction was mainly due to influx of Ca from extracellular sources.