Maternal Exposure to Ethanol During Pregnancy and Lactation Affects Glutamatergic System and Induces Oxidative Stress in Offspring Hippocampus

BACKGROUND

Alcohol abuse during pregnancy leads to intellectual disability and morphological defects in the offspring. The aim of this study was to determine the effect of chronic maternal ethanol (EtOH) consumption during pregnancy and lactation on glutamatergic transmission regulation, energy deficit, and oxidative stress in the hippocampus of the offspring.

METHODS

EtOH was administered to dams in drinking water at increasing doses (2 to 20%) from the gestation day 5 to lactation day 21. EtOH and tap water intake by treated and control groups, respectively, were measured daily.

RESULTS

Results showed that EtOH exposure does not affect fluid intake over the course of pregnancy and lactation. The toxicity of maternal exposure to EtOH was demonstrated by decreased offspring body weight at experimental age, on postnatal day 21. Moreover, maternal EtOH exposure decreased (45) Ca(2+) influx in the offspring's hippocampus. Corroborating this finding, EtOH increased both Na(+) -dependent and Na(+) -independent glial [(14) C]-glutamate uptake in hippocampus of immature rats. Also, maternal EtOH exposure decreased glutamine synthetase activity and induced aspartate aminotransferase enzymatic activity, suggesting that in EtOH-exposed offspring hippocampus, glutamate is preferentially used as a fuel in tricarboxylic acid cycle instead of being converted into glutamine. In addition, EtOH exposure decreased [U-14C]-2-deoxy-D-glucose uptake in offspring hippocampus.

CONCLUSIONS

The decline in glucose transport coincided with increased lactate dehydrogenase activity, suggesting an adaptative response in EtOH-exposed offspring hippocampus, using lactate as an alternative fuel. These events were associated with oxidative damage, as demonstrated by changes in the enzymatic antioxidant defense system and lipid peroxidation. Taken together, the results demonstrate that maternal exposure to EtOH during pregnancy and lactation impairs glutamatergic transmission, as well as inducing oxidative stress and energy deficit in immature rat hippocampus.

Pulsed ultrasound and dimethylsulfoxide gel treatment reduces the expression of pro-inflammatory molecules in an animal model of muscle injury

Studies have shown an exacerbated increase in proinflammatory markers during and after muscle injury. In this way, interventions that reduce inflammatory activation appear to be of great interest in muscle injury therapy. Thus, the preset study evaluated the effect of low-intensity pulsed ultrasound (LIPUS) and dimethylsulfoxide (DMSO) on the proinflammatory molecules in an animal model of traumatic muscle injury. Forty-eight 3-month old male Wistar rats were divided into six groups (n = 8/group): sham; muscle injury without treatment; muscle injury and gel-saline (0.9%); muscle injury and gel-DMSO (15 mg/kg); muscle injury and LIPUS plus gel-saline; and muscle injury and LIPUS plus gel-DMSO. Two, 12, 24 and 48 h after trauma, four groups received one of the treatments described. One hour after, Western blot was performed to quantify proinflammatory protein levels. We observed greater protein levels of TNFα (3.9 times), IL-1β (3.6 times), JNK phosphorylation (4.2 times) and NFκB (3.8 times) in muscle injury group. However, the combined LIPUS with DMSO resulted in significantly lower levels of TNFα (2.2 times), IL-1β (2.1 times), JNK phosphorylation (2.4 times), and NFκB (2.1 times). The results demonstrate that LIPUS associated with DMSO gel can attenuate TNFα, IL-1β, NFκB protein levels and JNK phosphorylation in traumatic muscle injury.

Endurance exercise training ameliorates insulin resistance and reticulum stress in adipose and hepatic tissue in obese rats

Obesity-induced endoplasmatic reticulum (ER) stress has been demonstrated to underlie the induction of obesity-induced JNK and NF-κB activation inflammatory responses, and generation of peripheral insulin resistance. On the other hand, exercise has been used as a crucial tool in obese and diabetic patients, and may reduce inflammatory pathway stimulation. However, the ability of exercise training to reverse endoplasmatic reticulum stress in adipose and hepatic tissue in obesity has not been investigated in the literature. Here, we demonstrate that exercise training ameliorates ER stress and insulin resistance in DIO-induced rats. Rats were fed with standard rodent chow (3,948 kcal kg(-1)) or high-fat diet (5,358 kcal kg(-1)) for 2 months. After that rats were submitted to swimming training (1 h per day, 5 days for week with 5% overload of the body weight for 8 weeks). Samples from epididymal fat and liver were obtained and western blot analysis was performed. Our results showed that swimming protocol reduces pro-inflammatory molecules (JNK, IκB and NF-κB) in adipose and hepatic tissues. In addition, exercise leads to reduction in ER stress, by reducing PERK and eIF2α phosphorylation in these tissues. In parallel, an increase in insulin pathway signaling was observed, as confirmed by increases in IR, IRSs and Akt phosphorylation following exercise training in DIO rats. Thus, results suggest that exercise can reduce ER stress, improving insulin resistance in adipose and hepatic tissue.