Voorbeelden van leptin

• Researchers isolated a natural hormone they called leptin, which tells the brain that the body has enough fatty tissue.

• While adding leptin to obese mice made them slimmer, it hasn't worked very well in humans.

• People who routinely slept five hours a night had a higher level of ghrelin and a lower level of leptin than those who slept eight hours.

• Therefore, agerelated leptin resistance may be caused by increased adiposity or prolonged exposure to the elevated leptin, or both.

• A subsequent unpublished analysis demonstrated that leptin peptide decreased with age in the same mice.

• Evidence that the diabetes gene encodes the leptin receptor : identification of a mutation in the leptin receptor gene in db/db mice.

• Central administration of leptin inhibits food intake and activates the sympathetic nervous system in rhesus macaques.

• Thus circulating leptin appears to increase until late middle age, then, as in rodents, begins to decrease with advanced old age.

• Circulating leptin in patients with anorexia nervosa, bulimia nervosa or binge-eating disorder : relationship to body weight, eating patterns, psychopathology and endocrine changes.

• However, the inverse correlation between leptin and age was significant in both men and women when analysed separately by gender.

• Nevertheless, the essential observation was that leptin gene expression decreased with age, with the main difference occurring between 15 and 24 months.

• Some evidence suggests that prolonged exposure to the elevated level of leptin may play a causative role in agerelated leptin resistance.

• There is also evidence to suggest that leptin, an adipose tissue-derived hormone, plays a role in both.

• Testosterone supplementation improved right grip strength and resulted in decreased leptin levels, with no change in body fat or body mass index.

• However, prolonged caloric excess results in dysregulation of post-receptor leptin signalling.

• Recombinant porcine leptin reduces feed intake and stimulates growth hormone secretion in swine.

• It is still unknown whether lifelong exercise can prevent the development of leptin resistance during aging.

• A mutation in the human leptin receptor gene causes obesity and pituitary dysfunction.