New method for treating sleep dyspnea
December 04, 2018 Source: Chinese Journal of Science
Window._bd_share_config={ "common":{ "bdSnsKey":{ },"bdText":"","bdMini":"2","bdMiniList":false,"bdPic":"","bdStyle":" 0","bdSize":"16"},"share":{ }};with(document)0[(getElementsByTagName('head')[0]||body).appendChild(createElement('script')) .src='http://bdimg.share.baidu.com/static/api/js/share.js?v=89860593.js?cdnversion='+~(-new Date()/36e5)];A study conducted by American scientists recently showed that a well-known hormone that regulates hunger and body weight can relieve respiratory problems during sleep by nasal administration.
Researchers say they have successfully administered drugs through the nasal cavity of experimental animals, which may help develop easier-to-use therapies for patients with sleep apnea, such as sleep apnea syndrome.
The findings were published online in the American Journal of Respiratory and Critical Care Medicine.
Leptin, first discovered in 1994, is a hormone produced by fat cells that acts on the appetite center of the brain to help regulate appetite. Vsevolod Y Polotsky of Johns Hopkins University School of Medicine said: "The effect of leptin on obesity/inhibition of overeating has not been confirmed in human experiments, but its effect on the respiratory system has brought new treatment. possibility."
Polotsky's research focuses on finding new strategies for the treatment of obstructive sleep apnea, a potentially fatal disease affecting approximately 30% of American adults. The prevalence of obese people is as high as 50%. The cause of this disease is that the patient's upper airway is closed during sleep, causing the breathing to stop, resulting in hypoxia. Obesity patients also often have another health problem known as obesity hypoventilation syndrome, which is usually accompanied by sleep apnea.
The most common effective treatment for these sleep problems is the regular use of continuous positive airway pressure (CPAP) masks and machines to increase the air pressure in the throat by mechanical force to ensure that the airway remains unobstructed during sleep. However, some patients feel that the CPAP machine is cumbersome, uncomfortable to wear, will make noise, and the activity is restricted, so it will stop using.
According to Polotsky, previous studies have shown that leptin is important for regulating respiration and can successfully treat symptoms of sleep-disordered breathing in obese mice lacking leptin. However, mice that are obese due to diet are resistant to leptin and do not respond when leptin is injected into their abdomen.
Slava Berger, a postdoctoral researcher at Polotsky Labs, said: "One of the main causes of leptin resistance is the hormones injected by injection, which are difficult to cross the blood-brain barrier and enter the target brain cells."
To test this idea, the researchers first performed adult fat mice for 16 weeks of high-fat feeding to make them obese. Because leptin causes weight loss in the long run, and weight loss also reduces breathing problems, the researchers first evaluated the direct effect of single-dose leptin on sleep breathing before producing weight loss.
The researchers measured the amount of air inhaled by the mice by temperature changes and the number of oxygen deficits during sleep in the mice. They installed a collar on the neck of the mouse to observe blood oxygen levels, similar to measuring blood oxygen levels on a human finger with a clip in an emergency care setting. The results showed that only mice administered via the nasal cavity for leptin increased ventilation by more than 40% during sleep, alleviating the problem of upper airway obstruction and reducing the number of oxygen levels in mice by more than half.
The researchers stained brain neurons in nasally-administered mice and found that the leptin receptor on the surface of neurons binds to detectable leptin, which means that this method of administration bypasses the blood-brain barrier and will Leptin is transported directly to the brain to avoid leptin resistance.
To further investigate the long-term metabolic effects of leptin treatment, the researchers administered a portion of these obese mice via nasal or abdominal leptin for two weeks. The results still show that only mice that were administered leptin through the nasal cavity showed reduced food intake and weight loss. These mice lost 1 gram of body weight, accounting for almost 3% of the total weight; mice with abdominal leptin gained more than 3 grams of body weight, indicating the presence of leptin resistance.
Polotsky said: "We believe this study is the first evidence to reduce sleep-disordered breathing through leptin nasal administration. We plan to further study the effects of different doses of leptin administered to mice via the nasal cavity."
"The ability to identify key molecules that regulate breathing and understand how to use these molecules to treat diseases including sleep apnea syndrome is a major achievement." Director of the National Center for Sleep Disorders, National Heart, Lung, and Blood Institute, National Institutes of Health Michael Twery commented, "This discovery has created the conditions for the development of new therapies."
Cost is also one of the considerations for this therapy. The average cost of a CPAP device is $500 to $3,000. Polotsky and Berger estimate that if nasal leptin administration is clinically safe and effective, its cost may be similar to inhaled insulin, which costs about $25 per bottle.
Stainless Steel Foam Fire Extinguisher
Stainless Steel Foam Fire Extinguisher,Sus 4L Foam Fire Extinguisher,Sus 6L Foam Fire Extinguisher,Stainless Steel 6L Foam Fire Extinguisher
JIANGSU NEW FIRE FIGHTING TECHNOLOGY CO.,LTD , https://www.newayfire.com