Brindle N P, Ontko J A
Cardiovascular Biology, Oklahoma Medical Research Foundation, Oklahoma City.
Biochem J. 1988 Mar 1;250(2):363-8. doi: 10.1042/bj2500363.
The effect of adrenaline on triacylglycerol synthesis and secretion was examined in isolated rat hepatocytes. Cells were incubated with 0.5 mM-[1-14C]oleate, and the accumulation of triacylglycerol and [14C]triacylglycerol was measured in the incubation medium. Triacylglycerol appearing in the medium was present in a form with properties similar to very-low-density lipoproteins. Triacylglycerol, [14C]triacylglycerol and [14C]phospholipid contents of hepatocytes were also determined. Addition of 10 microM-(-)adrenaline decreased accumulation of glycerolipid in the incubation medium and also decreased cellular [14C]phospholipid content. Prazosin abolished these effects, whereas propranolol did not. The hormone did not affect cellular triacylglycerol content or rates of incorporation of [1-14C]oleate into cell triacylglycerol. The effect of adrenaline on the removal of newly secreted triacylglycerol and the secretion of synthesized glycerolipid was also examined. The catecholamine did not affect rates of removal of newly secreted triacylglycerol. Adrenaline did inhibit the secretion of pre-synthesized lipid by the cells, as assessed by the appearance of radiolabelled triacylglycerol from hepatocytes that had been preincubated with [1,2,3-3H]-glycerol. Adrenaline did not affect rates of fatty acid uptake by hepatocytes, but did stimulate oxidation of [1-14C]oleate, principally to 14CO2.
在分离的大鼠肝细胞中研究了肾上腺素对三酰甘油合成和分泌的影响。将细胞与0.5 mM-[1-¹⁴C]油酸一起孵育，并测定孵育培养基中三酰甘油和[¹⁴C]三酰甘油的积累。培养基中出现的三酰甘油以与极低密度脂蛋白性质相似的形式存在。还测定了肝细胞中三酰甘油、[¹⁴C]三酰甘油和[¹⁴C]磷脂的含量。添加10 μM-(-)肾上腺素可降低孵育培养基中甘油脂的积累，也可降低细胞中[¹⁴C]磷脂的含量。哌唑嗪可消除这些作用，而普萘洛尔则不能。该激素不影响细胞三酰甘油含量或[1-¹⁴C]油酸掺入细胞三酰甘油的速率。还研究了肾上腺素对新分泌的三酰甘油清除和合成甘油脂分泌的影响。儿茶酚胺不影响新分泌的三酰甘油的清除速率。肾上腺素确实抑制了细胞分泌预先合成的脂质，这通过用[1,2,3-³H]-甘油预孵育的肝细胞中放射性标记的三酰甘油的出现来评估。肾上腺素不影响肝细胞对脂肪酸的摄取速率，但确实刺激了[1-¹⁴C]油酸的氧化，主要氧化为¹⁴CO₂。
