The pineal gland, through melatonin, seems to be of fundamental importance in determining the metabolic adaptations of adipose and muscle tissues to physical training. Evidence shows that pinealectomized animals fail to develop adaptive metabolic changes in response to aerobic exercise and therefore do not exhibit the same performance as control-trained animals. The known prominent reduction in melatonin synthesis in aging animals led us to investigate the metabolic adaptations to physical training in aged animals with and without daily melatonin replacement. Male Wistar rats were assigned to four groups: sedentary control (SC), trained control (TC), sedentary treated with melatonin (SM), and trained treated with melatonin (TM). Melatonin supplementation lasted 16 wk, and the animals were subjected to exercise during the last 8 wk of the experiment. After euthanasia, samples of liver, muscle, and adipose tissues were collected for analysis. Trained animals treated with melatonin presented better results in the following parameters: glucose tolerance, physical capacity, citrate synthase activity, hepatic and muscular glycogen content, body weight, protein expression of phosphatidylinositol 3-kinase (PI3K), mitogen-activated protein kinase (MAPK), and protein kinase activated by adenosine monophosphate (AMPK) in the liver, as well as the protein expression of the glucose transporter type 4 (GLUT4) and AMPK in the muscle. In conclusion, these results demonstrate that melatonin supplementation in aging animals is of great importance for the required metabolic adaptations induced by aerobic exercise. Adequate levels of circulating melatonin are, therefore, necessary to improve energetic metabolism efficiency, reducing body weight and increasing insulin sensitivity.
Objective
Melatonin has been shown to increase brown adipose tissue (BAT) mass, which can lead to important metabolic effects, such as bodyweight reduction and glycemic improvement. However, BAT mass can only be measured invasively and. The gold standard for non-invasive measurement of BAT activity is positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro-d-glucose (18F-FDG PET). There is no study, to our knowledge, that has evaluated if melatonin influences BAT activity, measured by this imaging technique in animals.
Methods
Three experimental groups of Wistar rats (control, pinealectomy, and pinealectomy replaced with melatonin) had an 18F-FDG PET performed at room temperature and after acute cold exposure. The ratio of increased BAT activity after cold exposure/room temperature was called “acute thermogenic capacity” (ATC) We also measured UCP-1 mRNA expression to correlate with the 18F-FDG PET results.
Results
Pinealectomy led to reduced acute thermogenic capacity, compared with the other groups, as well as reduced UCP1 mRNA expression.
Conclusion
Melatonin deficiency impairs BAT response when exposed to acute cold exposure. These results can lead to future studies of the influence of melatonin on BAT, in animals and humans, without needing an invasive evaluation of BAT.
Purpose: to assess the knowledge of mothers about the heel prick test, develop contents on this test to make it available on the "Babies' Portal" website, evaluate and validate the informative material developed. Methods: this study was conducted in three stages, that is, the first stage which is about a descriptive study involving 105 mothers of newborn children before performing the neonatal screening "Heel Prick Test", the second one consisting in the development of the website "Babies' Portal", and the third stage, the evaluation and validation of this material carried out by 20 parents of children between zero and 36 months old, who underwent the neonatal screening Heel Prick Test by accessing the website "Babies' Portal". Results: although the interviewed mothers knew that their children had the right to be tested, they showed no knowledge of the diseases that can be prevented, time of diagnosis, nor the consequences arising from the lack of early diagnosis and treatment. The website creation and validation gathered basic information about the Heel Prick Test, and the participants regarded the content from satisfactory to excellent. Conclusion: it is necessary that families know not only about the procedures their children will undergo, but also the reason they are performed and the consequences of failing in doing so.
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