El tejido adiposo, ¿solo un almacén de energía?

Abstract

Whenfoodmeetsenergyrequirements, thebodystores in theliver and in themuscletheexcessofcalories as glycogen and triacylglycerols in the adipose tissue. Morphologically and functionally, itisclassifiedintowhite and browntissues. Brown tissue has manylargemitochondria and storestriacylglycerols in vacuoles and dissipatesenergy as heat; whitetissuestoresenergy as lipiddropletsthatoccupymostoftheadipocyte’svolume. After foodintakeinsulinisreleased, which causesGLUT4 externalizationintothecellularmembranetoabsorbglucose. Chylomicronsor VLDL transporttriacylglycerolsto adipose tissuedepots. Duringfasting, bytheactionofglucagon, enzymes are releasedthatwill degrade tri-, di- and mono-glycerolstoreleasefattyacids. Adipose tissuereleases pro and anti-inflammatorycytokines, as well as leptin and adiponectinthatregulateappetite and satiety. AMPK isactivated in response to a decrease in thecell’senergy and helpsittomaintainitsenergetic balance. In theadipocyte, itpromotesthedegradationoftriacylglycerolsreleasingfattyacidsto be used as anenergysource. More studies are neededtolearn more aboutthefunctionof adipose tissue as a regulatorofthemetabolism and notonly as anenergystorage. Keywords: Adipocyte; brown adipose tissue; white adipose tissue; GLUT4; triacylglycerol; AMPK.