Effect Of Hypoxia On Feeding Behavior Of Rats

In recent years, obesity has become one of the most popular chronic disease in the world. Weight control has been one of the challenges faced by the people. Animals’weight significantly decreased after hypoxie exposure. Recent clinical studies have found that obese individuals at appropriate high altitudes can loss weight, and imporve the hypertension symptoms, so appropriate altitude exposure may become a effective new way of weight control for obese individuals. Weight of organism has tight relation with the feeding behavior, experiments also prove that hypoxic exposure can significantly decrease not only the wight but also food intake. Feeding behavior can be regulated by energy metabolism and reward system. Therefore, our experiment study explore the effect of hypoxia on feeding behavior from both energy metabolism and reward behavior.In our experiment, male rats (Sprague-Dawley) ware used. Using decompression chamber simulated plateau hypoxia environment hormone related to energy state ware assayed and some behaviors ware observed. To study the effect of hypoxia on feeding behavior through the metabolic and reward system. Experimental rats were divided into control group (local altitude is60m, oxygen partial pressure156MMHG, atmospheric oxygen levels of20.9%),3000m altitude hypoxic group (oxygen partial pressure110MMHG, oxygen levels in the atmosphere14.4%), hypoxic exposure time is1day,5days and10days. Rats were housed individually and maintained on a12:12-hr light-dark cycle (lights on at7a.m.),22±1℃temperature,60±10%humidity, free to feed and drink water. All experimental rats to weighing weight and food intake in provision time. The rats which in hypoxia exposure1day group did the test for metabolic system and reward system.Test the physiological reaction of the body for energy demand by blood glucose, serum triglyceride levels, blood leptin levels. Reward system test by consuming the natural reward (sweet milk), food induction conditions place preference to reactions the body desire for food. Serum corticosterone levels is to test that if hypoxia affect rats.The experimental results:1, Hypoxia after1day, compared with control group, the3000meters group weight decreased1.6%, food consumption fell by21.2%, significantly increased with serum corticosterone, and serum triglyceride decreased significantly. Blood glucose, insulin and blood leptin had no significant difference.3000meters group rats are higher than control group rats in sweet milk intake, there are significant differences. Decreased significantly with condition place preference behaviour.2, Hypoxia after5days, compared with control group,3000meters hypoxic exposure group rats’body weight decreased5.6%, food intake decreased5.4%, no significant difference. Serum corticosterone levels significantly increased compared with control group, and blood glucose, serum triglyceride, blood leptin had no significant difference.3, Hypoxic exposure after10days, compared with control group,3000meters in low oxygen exposure group rats’ body weight decreased6.1%, food intake decreased8.6%, no significant difference. Serum cortciosterone, blood glucose, serum triglyceride, blood leptin had no significant difference.Conclusion:Hypoxic exposure after1day,3000meters of hypoxia group rats produced larger stress reaction, lead to most of the energy is to mobilize the body in response to hypoxic exposure to the environmental changes (stress). The high levels of corticosterone promote hepatic glycogen dan lipolysis decomposition, as a result, blood glucose was no significant change, but hepatic glycogen and triglyceride declined significantly. Moreover, the rise of glucocorticoid can effectively activate the reward system, so the intake of the rats of sweet milk significantly increases, but due to the mobility and conditioned memory under the influence of hypoxia, the condition place preference decreased. Although the reward system is activated, it is not enough to reverse the double feeding behavior by energy and active suppression. Following the exposure, corticosterone content gradually decreases, blood glucose showed a downward trend, to show that the body gradually adapt to the low oxygen environment, energy metabolism to restore balance at this time, and body for energy demand increases, and increased food intake.