Effects of a 4-week aerobic exercise on lipid profile and expression of LXR alpha in rat liver

Objective: Liver X receptors [LXRs] are ligand-activated transcription factors of the nuclear hormonal receptor superfamily which modulate the expression of genes involved in cholesterol homeostasis. Hence, further unraveling of the molecular function of this gene may be helpful in preventing cardiovascular diseases

Materials and Methods: This experimental intervention study included twelve adult Wistar male rats [12-14 weeks old, 200-220 g] which were divided into the control [n=6] and training [n=6] groups. The training group received exercise on a motor-driven treadmill at 28 meters/minute [0% grade] for 60 minutes a day, 5 days a week for 4 weeks. Rats were sacrificed 24 hours after the last session of exercise. A portion of the liver was excised, immediately washed in ice-cold saline and frozen in liquid nitrogen for extraction of total RNA. Plasma was collected for high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], total cholesterol [TC] and triglycerides [TG] measurements. All variables were compared by independent t test

Results: A significant increase in LXR alpha transcript level was observed in trained rats [P<0.01]. Plasma HDL-C concentration was also significantly higher [P<0.01] in trained rats. There was a significant decrease in the concentrations of LDL-C [P<0.01] and TC [P<0.02], and the ratios of TC/HDL-C [P<0.001] and LDL/HDL-C [P<0.002] in trained rats. However, the TG concentration was unchanged [P>0.05]

Conclusion: We found that endurance training induces significant elevation in LXR alpha gene expression and plasma HDL-C concentration resulting in depletion of the cellular cholesterol. Therefore, it seems that a contributor to the positive effects of exercise in cardiovascular disease prevention is through the expression of LXR alpha, which is a key step in reverse cholesterol transport

Effect of nanosilver particles on Procaspase-3 expression in newborn rat brain

Objective: Nanotechnology focuses on materials having at least one dimension of less than 100 nanometers. Nanomaterials such as Nanosilver [NS] have unique physical and chemical properties such as size, shape, surface charge. NS particles are thought to induce neuronal degeneration and necrosis in the brain. It has been reported that NS particles generate free radicals and oxidative stress which alters gene expression and induces apoptosis. This study was designed to evaluate whether the detrimental effect of NS particles is through the activation of Procaspase-3 during fetal neural development

Materials and Methods: In this experimental study, thirty Wistar female rats at day one of pregnancy were semi-randomly distributed into three groups of ten. Group 1, the control group, had no treatment. From day 1 to the end of pregnancy, groups 2 and 3 received 1 and 10 ppm NS respectively via drinking water. Newborn rats were sacrificed immediately after birth and their brains were dissected and kept frozen. Total RNA, extracted from brain homogenates, was reverse transcribed to cDNA. Quantitative real-time polymerase chain reaction [PCR] analysis was undertaken to estimate the expression level of Procaspase-3

Results: Developmental exposure to NS induced neurotoxicity and apoptosis. This correlated with a significant increase in Procaspase-3 expression level especially at 10 ppm NS

Conclusion: The pro-apoptotic activity of NS in cells is likely to due to the dysregulation of Procaspase-3

[Evaluating the effectiveness of combination of Pure and Zeta methods in isolating mature sperms with normal chromatin structure]

Isolating sperms with normal chromatin content is considered vital in Intra Cytoplasmic Sperm Injection treatment. Today, researchers are trying to find new procedures to select sperms with normal chromatin content and morphology. This study examines the effectiveness of Zeta, Density Gradient Centrifugation [Pure Sperm] and combination of Pure-Zeta procedures in selecting sperms with normal chromatin structure using Sperm Chromatin Dispersion [SCD], and Chromomycin A3 [CMA3]. 28 patients participated in the study. Semen samples were analyzed according to WHO criteria. The samples were then divided into four equal portions of control, Zeta method, DGC [Pure Sperm] method and Pure-Zeta method. Sperm morphology [Diff Quick Staining], protamine deficiency [CMA3] and DNA integrity [SCD] were carried out for all the samples. The results were analyzed using ANOVA. P< 0.05 was considered significant. There was a significant reduction in the percentage of sperm protamine deficiency and DNA fragmentation in Zeta, Pure and Pure-Zeta method groups compared to the control group [p <0.05]. In terms of a normal morphology, Pure and Pure-Zeta procedures proved significantly different from the control group [p<0.05 normal morphology]. Zeta, Pure and Pure-Zeta procedures did no differ in isolating sperms with regard to normal morphology, protamine content and DNA fragmentation [p > 0.05]. Based on the result, Zeta and Pure methods improved selection of sperms with normal morphology, protamine content and DNA integrity. Yet, the combination of Pure-Zeta was more effective in terms of isolating spermatozoa with normal morphology, protamine content and DNA integrity than when Zeta and Pure methods were implemented individually