Vernon R G, Finley E, Taylor E
Biochem J. 1983 Oct 15;216(1):121-8. doi: 10.1042/bj2160121.
The rate of noradrenaline-stimulated lipolysis is lower in fat-cells from lactating than from pregnant rats; this difference is eliminated by the addition of adenosine deaminase [Aitchison, Clegg & Vernon (1982) Biochem. J. 202, 243-247]. The activity of 5'-nucleotidase, and hence the capacity of the cells to synthesize adenosine, was the same in fat-cells and also stromal cells of adipose tissue from pregnant, lactating and male rats. The response and sensitivity of fat-cells to the anti-lipolytic effects of adenosine were measured by incubating cells in the presence of noradrenaline, adenosine deaminase (to remove endogenous adenosine) and various concentrations of the adenosine analogue N6-phenylisopropyladenosine (PIA). PIA caused a greater inhibition of the rate of noradrenaline-stimulated lipolysis in adipocytes from lactating than from pregnant rats. The concentration of PIA required to inhibit by 50% the rate of noradrenaline-stimulated lipolysis fell from over 100 nM for fat-cells from pregnant rats to 30 nM for fat-cells from lactating rats. The decreased rate of noradrenaline-stimulated lipolysis during lactation was not due to the smaller mean cell volume of adipocytes during this state.
哺乳期大鼠脂肪细胞中去甲肾上腺素刺激的脂肪分解速率低于妊娠大鼠；添加腺苷脱氨酶可消除这种差异[Aitchison, Clegg & Vernon (1982) Biochem. J. 202, 243 - 247]。5'-核苷酸酶的活性，以及细胞合成腺苷的能力，在妊娠、哺乳和雄性大鼠的脂肪细胞以及脂肪组织的基质细胞中是相同的。通过在去甲肾上腺素、腺苷脱氨酶（去除内源性腺苷）和不同浓度的腺苷类似物N6-苯基异丙基腺苷（PIA）存在下孵育细胞，来测量脂肪细胞对腺苷抗脂肪分解作用的反应和敏感性。PIA对哺乳期大鼠脂肪细胞中去甲肾上腺素刺激的脂肪分解速率的抑制作用比对妊娠大鼠脂肪细胞的抑制作用更强。抑制去甲肾上腺素刺激的脂肪分解速率50%所需的PIA浓度，从妊娠大鼠脂肪细胞的超过100 nM降至哺乳期大鼠脂肪细胞的30 nM。哺乳期去甲肾上腺素刺激的脂肪分解速率降低并非由于该状态下脂肪细胞的平均细胞体积较小。
