Cellular events underlying catecholamine-induced thermogenesis: cation transport in brown adipocytes.
Evidence supporting the hypothesis that the active transport of Na+ and K+ contributes significantly to catecholamine-mediated brown fat thermogenesis is reviewed. Such evidence indicates that the Na+/K+ membrane pump is activated following norepinephrine interaction with alpha- and beta-adrenergic membrane receptors. That the involvement of the pump in the thermogenic response is considerable is indicated by the finding that pump inhibition is accompanied by a 50--70% reduction of the catecholamine-evoked respiratory stimulation of isolated hamster brown adipocytes. This inhibitory effect of pump blockade suggests that in the norepinephrine-activated brown adipocyte, the pump generates a stimulatory signal for pathways of substrate oxidation, the operation of these being associated with conversion of chemical energy to heat.
D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009638:Norepinephrine / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D012964:Sodium / Q000378:metabolism*
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D012964:Sodium; D011188:Potassium; D009638:Norepinephrine