Metabolic effects of exercise on childhood obesity: a current view / Efeitos metabólicos do exercício físico na obesidade infantil: uma visão atual

OBJECTIVE: To review the current literature concerning the effects of physical exercise on several metabolic variables related to childhood obesity. DATA SOURCE: A search was performed in Pubmed/MEDLINE and Web of Science databases. The keywords used were as follows: Obesity, Children Obesity, Childhood Obesity, Exercise and Physical Activity. The online search was based on studies published in English, from April 2010 to December 2013. DATA SYNTHESIS: Search queries returned 88,393 studies based on the aforementioned keywords; 4,561 studies were selected by crossing chosen keywords. After applying inclusion criteria, four studies were selected from 182 eligible titles. Most studies found that aerobic and resistance training improves body composition, lipid profile and metabolic and inflammatory status of obese children and adolescents; however, the magnitude of these effects is associated with the type, intensity and duration of practice. CONCLUSIONS: Regardless of the type, physical exercise promotes positive adaptations to childhood obesity, mainly acting to restore cellular and cardiovascular homeostasis, to improve body composition, and to activate metabolism; therefore, physical exercise acts as a co-factor in fighting obesity. .

OBJETIVO: Revisar a literatura atual a respeito dos efeitos do exercício físico sobre diferentes variáveis metabólicas da obesidade infantil. FONTES DE DADOS: A pesquisa foi feita nas bases de dados Pubmed e Web of Science. Os descritores usados foram: obesity, children obesity, childhood obesity, exercise e physical activity. A pesquisa eletrônica foi feita com base nos estudos publicados de abril de 2010 a dezembro de 2013, em idioma inglês. SÍNTESE DOS DADOS: O rastreamento dos estudos com os descritores encontrou 88.393. Após cruzamento entre os descritores, obtiveram-se 4.561. Desses, depois da análise dos títulos, foram cogitados 182 relevantes referências, submetidos então aos critérios de inclusão/exclusão, e totalizaram, no fim, 39. A maioria dos estudos relacionou a prática de exercícios físicos aeróbicos e resistidos à melhoria da composição corporal, à regulação do perfil lipídico e metabólico e ao estado inflamatório de crianças e adolescentes obesos. Entretanto, a magnitude dos efeitos está associada ao tipo, à intensidade e à duração da prática. CONCLUSÕES: O exercício físico, independentemente do tipo, mostra-se capaz de promover adaptações positivas sobre a obesidade infantil, principalmente por atuar na restauração da homeostase celular e sistema cardiovascular, na melhoria da composição corporal e também aumento da ativação metabólica. .

Effects of Co-Administration of Intrathecal Nociceptin/Orphanin FQ and Opioid Antagonists on Formalin-Induced Pain in Rats

PURPOSE: Nociceptin/orphanin FQ (N/OFQ) as an endogeneous hexadecapeptide is known to exert antinociceptive effects spinally. The aims of this study were to demonstrate the antinociceptive effects of i.t. N/OFQ and to investigate the possible interaction between N/OFQ and endogenous opioid systems using selective opioid receptor antagonists in rat formalin tests. MATERIALS AND METHODS: I.t. N/OFQ was injected in different doses (1-10 nmol) via a lumbar catheter prior to a 50 microL injection of 5% formalin into the right hindpaw of rats. Flinching responses were measured from 0-10 min (phase I, an initial acute state) and 11-60 min (phase II, a prolonged tonic state). To observe which opioid receptors are involved in the anti-nociceptive effect of i.t. N/OFQ in the rat-formalin tests, naltrindole (5-20 nmol), beta-funaltrexamine (1-10 nmol), and norbinaltorphimine (10 nmol), selective delta-, micro- and kappa-opioid receptor antagonists, respectively, were administered intrathecally 5 min after i.t. N/OFQ. RESULTS: I.t. N/OFQ attenuated the formalin-induced flinching responses in a dose-dependent manner in both phases I and II. I.t. administration of naltrindole and beta-funaltrexamine dose-dependently reversed the N/OFQ-induced attenuation of flinching responses in both phases; however, norbinaltorphimine did not. CONCLUSION: I.t. N/OFQ exerted an antinociceptive effect in both phases of the rat-formalin test through the nociceptin opioid peptide receptor. In addition, the results suggested that delta- and micro-opioid receptors, but not kappa-opioid receptors, are involved in the antinociceptive effects of N/OFQ in the spinal cord of rats.

Effects of chronic systemic administration of opioid peptides, naloxone and N-acetyl beta-endorphin antiserum on gonadotropins and testicular functions in the rat.

Systemic administration of opioid peptides, methionine-enkephalin and beta-endorphin, chronically, lowered gonadotropin levels in plasma and had an inhibitory effect mainly on the testicular enzymes hyaluronidase, acid phosphatase and on incorporation of 3[H] thymidine in the tissue. When rats were similarly treated with opioid peptide antagonist naloxone and N-acetyl beta-endorphin antiserum, induced an opposite effect. This is either the direct effect of opioid peptides/antagonist on the gonads or it may be via the circulating levels of gonadotropin.

Studies on the effect of intratesticular administration of opioid peptides, naloxone or N-acetyl beta-endorphin antiserum on some testicular parameters in rats.

Opioid peptides have been localized in a variety of peripheral tissues like placenta, thyroid, pancreas, gastrointestinal tract, in the reproductive tract of male and female and in the testes of rats. Immunoassayable material was detected in extracts of gonads, reproductive tract and accessory reproductive organs. Studies with naloxone have suggested that beta-endorphin may have an important role in steroidogenesis and may have a role in regulating transport of luminal material. In our studies met-enkephalin, beta-endorphin, naloxone or N-acetyl beta-endorphin antiserum were microinjected intra testicularly once on alternate days for one week and autopsied 24 h after the last injection. Intratesticular administration of 25, 50 and 100 micrograms doses of naloxone induced significant decrease in in vitro secretion of testosterone per se, which was significantly greater with 50 micrograms dose than with those of the other two doses. A 25 micrograms dose had no effect on hyaluronidase or acid phosphatase activity while 50 micrograms dose significantly decreased the enzyme activity. One hundred micrograms dose also significantly decreased hyaluronidase activity. Intratesticular injection of 10 micrograms met-enkephalin or 1 microgram beta-endorphin significantly decreased hyaluronidase activity whereas 20 microliters N-acetyl beta-endorphin antiserum increased the specific activity of hyaluronidase. There was no change in the weight of the testes on treatment with the above agents.