ghrelin
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.

SMART Vocabulary: related words and phrases

Biochemistry
adipose
adrenalin
albumin
aldosterone
amino acid
endonuclease
endorphin
enzymatic
enzymatically
enzyme
mRNA
mycoprotein
non-enzymatic
nuclease
nucleic acid
spike protein
T level
testosterone
trace element
transfer RNA

Examples of leptin

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A subsequent unpublished analysis demonstrated that leptin peptide decreased with age in the same mice.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