Hippocampal BDNF content in response to short- and long-term exercise.

The hippocampus is a region in the brain that is crucial for learning and memory. Previous researches proved that brain-derived neurotrophic factor (BDNF) is a probable responsible protein in the learning and memory formation process. BDNF content is thought to be affected by environmental enrichment and physical activity. The purpose of this research was to identify the effect of short- and long-term forced exercise on hippocampal BDNF levels. A total of 30 Wistar rats were randomly divided into three groups (control, short-term exercise and long-term exercise) and treated by treadmill running based on their group. As the treadmill running period finished, the animals were anesthetized. The hippocampus was dissected out immediately and BDNF content of the samples was assessed by ELISA. None of the exercise paradigms did make any significant change on hippocampal BDNF levels. Although exercise was proposed to up-regulate BDNF levels, these results show that the intensity or the duration of running paradigm used in forced exercise protocols here was not enough to affect BDNF levels in the hippocampus significantly.

Erythropoietin ameliorates oxidative stress and tissue injury following renal ischemia/reperfusion in rat kidney and lung.

OBJECTIVE: To study the effect of erythropoietin (EPO) treatment on renal and lung injury following renal ischemia/reperfusion (I/R). MATERIALS AND METHODS: Thirty male Wistar rats were assigned to three groups of 10 rats each. The first group was sham-operated, the second was subjected to renal I/R (30 min of ischemia followed by 24 h of reperfusion). The third group was subjected to renal I/R and treated with EPO in two doses: the first dose 1 h prior to ischemia (1,000 U/kg) and the second dose 6 h after ischemia (1,000 U/kg). RESULTS: The renal and lung tissue injury index, tissue serum blood urea nitrogen and creatinine (Cr) were higher in the renal I/R group compared to the renal I/R + EPO group; the difference was statistically significant (p < 0.05). Kidney and lung tissue glutathione peroxidase and superoxide dismutase levels were higher in the renal I/R + EPO group than the renal I/R group; the difference was also statistically significant (p < 0.05). CONCLUSION: The data showed that EPO pretreatment could be effective in reducing renal and lung injury following renal I/R and could improve the cellular antioxidant defense system. Hence EPO pretreatment may be effective for attenuating renal and lung injury after renal I/R-induced injury during surgical procedures, hypotension, renal transplantation and other conditions inducing renal I/R.

Long-term regular exercise promotes memory and learning in young but not in older rats.

BACKGROUND AND OBJECTIVE: By aging, some functions in nervous system like spatial memory are reduced. It has been shown that short-time physical activity can improve memory but there is much less data on the long-term exercising. In the present study, the aim was to clarify the effect of regular long-term physical activity on spatial memory and learning of young and middle aged and older male Wistar rats. MATERIALS AND METHODS: Sixty 3 months old rats were randomly divided in six equal groups. Experimental groups were treadmill exercised at speed 22m/min for 1h 6 days per week, and the program lasted 3, 6 and 9 months, respectively. At the end of training period, spatial memory of rats was tested using Morris Water Maze. RESULTS: Results indicated that regular physical activity significantly increased spatial memory (p<0.05) in young rats (6 months old) as compared to controls, but not in the older ones (9 and 12 months old). Nonetheless, spatial memory of these rats was significantly better than in younger ones in both groups (p<0.05). CONCLUSION: Spatial memory and learning increased due regular exercise in young rats. With progression of age up to 9 and 12 months the memory improved, but the programmed exercise had no positive effect on learning.

Evaluation of brain-derived neurotrophic factor in diabetic rats.

OBJECTIVE: Brain-derived neurotrophic factor (BDNF) is a member of neurotrophins family that plays a pivotal role in memory and learning. Brain-derived neurotrophic factor mediates health benefits of physical activity both in humans and animals. The nerve damage and cognitive impairment in diabetic rats are thought to be the result of reduced BDNF levels. The purpose of this study was to examine the effect of short- and long-term moderate forced exercise on BDNF levels in the hippocampus of type 1 diabetic rats. METHODS: A total of 40 male Wistar rats have been divided into four groups [control group, sedentary diabetic (SD) group, diabetic group with 2 week exercise, and diabetic group with 8 week exercise]. Exercised groups were treated with moderate treadmill running for 60 minutes per day on a rat treadmill. The animals were tested in a Morris water maze (MWM) for spatial memory and the BDNF levels in the hippocampus were assessed by ELISA kit. RESULTS: The Spatial memory test showed a significant improvement in exercised groups in comparison to sedentary groups. Based on the running protocol no significant difference was found on BDNF levels between groups. DISCUSSION: It was shown that spatial memory was improved by the exercise protocol, while the BDNF levels did not change significantly in any group. As a BDNF secretion in the brain is dependent on running paradigm factor, the protocol chosen might not be intensive or long enough to increase the BDNF levels. Exercise may improve spatial memory in type 1 diabetic rats in a way that BDNF is not included.

A comparative study pertaining to deleterious effects of diclofenac sodium and meloxicam on kidney tissue in rats.

NSAIDs (nonsteroidal anti-inflammatory drugs) are a class of drugs with analgesic, anti-inflammatory, and antipyretic effects. Diclofenac sodium is one of the world's most widely-prescribed NSAIDs. Meloxicam is another NSAID that was approved in the last several years. Treatment with NSAIDs may result in renal damage. Relatively, little is known about comparative nephrotoxicity of NSAIDs. Therefore, the present study was designed to compare the adverse effects of diclofenac sodium and meloxicam on renal tissue in rats. Forty eight Wistar male rats were randomly assigned into 3 groups of 16 animals each. Group C served as normal control and received normal saline. Group D and M received diclofenac sodium (2.3 mg/kg/day) and meloxicam (2.3 mg/kg/day), respectively. After 17 days, all rats were scarified. Their kidneys were then harvested and processed for histological examination. In addition to cellular details, renal tubular count and diameter were assessed with the light microscope. The data were analyzed using SPSS software. We found that the mean number of renal tubules was significantly lower in group D, than in group C. Moreover, the mean renal tubular diameter was significantly higher in group D than in group C. The present study showed that a considerable degree of nephrotoxicity resulted from diclofenac sodium, compared to meloxicam. We suggest that diclofenac sodium can be replaced with meloxicam.