| Abstract | Masno tkivo prema anatomskoj poziciji, histološkoj građi i funkciji možemo podijeliti
na smeđe i bijelo masno tkivo. Anatomski smeđe masno tkivo se nalazi potkožno,
intraperitonealno i intratorakalno. Primarna uloga smeđeg masnog tkiva je proizvodnja topline
sa povećanim unosom glukoze kako bi se ispravila poremećena termogeneza i kako bi se
uspostavile fiziološke funkcije u organizmu. Bijelo masno tkivo se nalazi u potkožju i
intraabdominalno. Uključeno je u metaboličke puteve lipogeneze, gdje potiče prelazak glukoze
u masne kiseline i kao takve ih zatim skladišti ili otpušta u cirkulaciju. Nastale masne kiseline
esterifikacijom prelaze u trigliceride i kao takve odlaze u cirkulaciju, nakon čega mogu biti
iskorištene kao izvor energije u stanicama. Kao endokrinološi organ, masno tkivo izlučuje
najvećim dijelom hormone leptin i adiponektin. Primarna uloga leptina je regulacija apetita
djelovanjem na receptore u hipotalamusu, dok adiponektin ima protuupalno djelovanje čime
sprečava nastanak metaboličkog sindroma i nakupljanje masti. Masno tkivo također izlučuje
retinol vezni protein-4 (RBP4), rezisitn, faktor nekroze tumora alfa (TNF-α) i interleukin-6
(IL-6). Uloga masnog tkiva u imunosnom odgovoru povezana je s nakupljanjem makrofaga,
što je potaknuto s pretilošću. Visoka razina masti uzrokuje smanjeno izlučivanje adiponektina
i kroničnu upalu u organizmu, pri čemu se masno tkivo nalazi u konstantnoj fazi upale niske
razine. Regrupacija makrofaga u masnom tkivu i hipertrofija adipocita stvara parakrini odnos
sa stalnim dotokom makrofaga u masno tkivo i povećanjem stupnja već postojeće upale.
Nakupljanje makrofaga u masnom tkivu također djeluje štetno na ostale organske sustave kao
što su kardiovaskularni sustav i jetra. Smanjeni učinci adiponektina dovode do oštećenja
endotela krvnih žila pomoću TNF-α. Potencijalni razvoj inzulinske rezistencije, također
posredovan nakupljanjem makrofaga u masnom tkivu, pak dovodi do oštećenja jetre, dodatno
pogoršavajući stanje kod pacijenata s već dijagnosticiranim bolestima jetre. |
| Abstract (english) | Adipose tissue can be classified into brown and white adipose tissue based on
anatomical position, histological structure, and function. Anatomically, brown adipose tissue
is located subcutaneously, intraperitoneally, and intrathoracically. The primary role of brown
adipose tissue is heat production, with increased glucose uptake to correct impaired
thermogenesis and to maintain physiological functions in the body. White adipose tissue is
found subcutaneously and intra-abdominally. It is involved in the metabolic pathways of
lipogenesis, promoting the conversion of glucose into fatty acids, which are then stored or
released into the circulation. Through esterification, the resulting fatty acids are converted into
triglycerides and enter the circulation, where they can be used as an energy source by cells. As
an endocrine organ, adipose tissue predominantly secretes the hormones leptin and adiponectin.
The primary role of leptin is appetite regulation through its action on hypothalamic receptors,
while adiponectin has anti-inflammatory effects that prevent metabolic syndrome and fat
accumulation. Adipose tissue also secretes retinol binding protein-4 (RBP4), resistin, tumor
necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). The role of adipose tissue in the
immune response is linked to macrophage accumulation, which is stimulated by obesity. High
fat levels lead to reduced adiponectin secretion and chronic inflammation in the body, with
adipose tissue remaining in a state of low-level inflammation. Macrophage recruitment in
adipose tissue and adipocyte hypertrophy create a paracrine relationship with a continuous
influx of macrophages and an increase in the level of existing inflammation. Macrophage
accumulation in adipose tissue also has adverse effects on other organ systems, such as the
cardiovascular system and liver. Reduced effects of adiponectin lead to endothelial damage via
TNF-α. Potential insulin resistance, also mediated by macrophage accumulation in adipose
tissue, can lead to liver damage, further worsening the condition in patients with pre-existing
liver diseases |
