Prostaglandin E2 increases the calcium concentration in rat brown adipocytes and their consumption of oxygen

Effects of prostaglandin E2 (PGE2) were examined on the oxygen consumption and intracellular calcium concentration of rat brown adipose tissue (BAT). PGE2 0.1 nM-1 microM increased oxygen consumption of the tissue blocks of BAT, with a maximum 2-13 min after PGE2 administration. PGE2 was most effective at 1 and 10 nM, and the oxygen consumption was elevated for over 40 min. Pretreatment of BAT with indomethacin, a prostaglandin synthesis inhibitor, did not affect the increase in oxygen consumption induced by noradrenaline. PGE2 at 1-10 nM gradually increased the intracellular calcium concentration of freshly dispersed single brown adipocytes by 3-4 times in 30 min. PGF2 also increased the intracellular calcium concentration of brown adipocytes in calcium-free medium. These results raise the possibility that PGE2 and noradrenaline affect heat genesis and metabolism of BAT independently.