Leptina - hormonul produs de celulel grase. Ingrasatul si lipsa de somn

Daca am nimerit bine topicul, as dori sa intreb sub ce forma se regasesc hormonii de mai sus (leptina, ghrelina si obestatin) in natura? Tinta intrebarii ar fi daca la cresterea animalelor pt sacrificat se folosesc in alimentatia acestora si daca ar putea ajunge pe aceasta cale in corpul uman?

S-a descoperit mai demult ca si celulele de grasime produc hormoni, deci ca fac parte din sistemul endocrin.

Cine nu doarme suficient sau se culca prea tarziu are tendinta la ingrasare deoarece se produce un hormon - leptina - care produce pofta aceea de mancare noaptea. Cine doarem suficient sau se culca mai devreme produce mai putina leptina si ca urmare este mai slab.
Cine este gras si doarme putin se face si mai gras !

- Cu cat esti mai gras cu atat mai multa leptina produci.
- cure de post de 24-72 de ore duce la scaderea leptinei chiar daca nu ai slabit deloc
- leptina creste de la lipsa de somn
- leptina creste de la stres emotional
- leptina scade de durata de la miscare
- leptina creste de le insulina (diabeticii se ingrasa automat daca iau prea multa insulina)

Interesant este faptul ca leptina artificiala nu a fost pana acum aprobata de medicament. Nu vrea deci nimeni sa stim de ea si sa slabim !

Cine doreste sa experimenteze poate sa o faca cu Leptin CH7 sau 9 care echilibereaza sau reduce nivelul.

Al doilea hormon este ghrelina care a fost descoperit la 5 ani dupa leptina.
Acest hormon are un rol la regularea apetitului, a foamei si a energiei dar joaca un rol si la invatat si la memorie.
El este produs in stomac, pancreas si hipotalamus. O cantitate mare in sange stimuleaza foamea.
Acest hormon pare sa actioneze independent de leptina. Si el este afectat de lipsa de somn.
Cine doarme putin are nivele mari de ghrelina in sange care duc la pofta de mancare marita.
Studii facute au aratat ca cei deprivati de somn au pofta marita de mancare pentru carbohidrati.

Un alt hormon descoperit in 2005 este Obestatin

Obestatin is a putative hormone that was described, in late 2005, to decrease appetite. Both obestatin and ghrelin are encoded by the same gene; the gene's product breaks apart to yield the two peptide hormones. The physiological value of this mechanism is unknown, and it should be noted that no secretory convertase is capable of cleaving the recombinant precursor by cleavage at the single basic residue required for generation of obestatin; thus, the physiological generation of this peptide is questionable.

http://en.wikipedia.org/wiki/Leptin

Leptin circulates in blood in free form and bound to proteins.[34] Leptin levels vary exponentially, not linearly, with fat mass.[35][36][full citation needed] Leptin levels in blood are higher between midnight and early morning, which could have an effect in suppressing appetite during the night while sleeping. The diurnal rhythm of blood leptin levels can be modified by meal-timing indicating that these levels are entrained to meal timing.

In humans, many instances are seen where Leptin dissociates from the strict role of communicating nutritional status between body and brain and no longer correlates with body fat levels:

Leptin level is decreased after short-term fasting (24–72 hours), even when changes in fat mass are not observed.[39][40][41]
Leptin plays a critical role in the adaptive response to starvation.[42][43]
In obese patients with obstructive sleep apnea, leptin level is increased, but decreased after the administration of continuous positive airway pressure. In non-obese individuals, however, restful sleep (i.e., 8–12 hours of unbroken sleep) can increase leptin to normal levels.
Serum level of leptin is reduced by sleep deprivation. However, a recent study showed that sleep deprivation was linked with higher levels of leptin.
Leptin level is increased by perceived emotional stress.
Leptin level is decreased or increased by increases in testosterone or estrogen level, respectively.
Leptin level is chronically reduced by physical exercise training.
Leptin level is increased by dexamethasone.
Leptin level is increased by insulin.
Leptin levels are paradoxically increased in obesity.

Dieters who lose weight experience a drop in levels of circulating leptin. This drop causes reversible decreases in thyroid activity, sympathetic tone, and energy expenditure in skeletal muscle, and increases in muscle efficiency and parasympathetic tone. The result is that a person who has lost weight has a lower basal metabolic rate than an individual at the same weight who has never lost weight; these changes are leptin-mediated, homeostatic responses meant to reduce energy expenditure and promote weight regain. Many of these changes are reversed by peripheral administration of recombinant leptin to restore pre-diet levels.

A decline in levels of circulating leptin also changes brain activity in areas involved in the regulatory, emotional, and cognitive control of appetite that are reversed by administration of leptin.

Leptin has not been approved for any therapeutic use.

http://en.wikipedia.org/wiki/Leptin

Despre Ghrelin
http://en.wikipedia.org/wiki/Ghrelin