The relationship between the effects of free fatty acid on the expression of gene encoding carbohydrate metabolism and insulin resistance during pregnancy

妊娠期和哺乳期母体代谢发生显著变化，尤其是葡萄糖和脂肪代谢。例如，在大鼠中，体脂量在怀孕期间增加，然后在分娩前减少，并在分娩后保持低水平。为了探讨母体脂肪量变化的相关因素，我们检测了未妊娠大鼠、妊娠大鼠和产后大鼠腹内脂肪组织中脂肪细胞因子、过氧化物酶体增殖物激活受体-γ (PPAR-γ)和肿瘤坏死因子-α (TNF-α)的mRNA水平。我们还研究了PPAR-γ和TNF-α可能促进的细胞凋亡是否参与了母体脂肪量的任何变化。测定脂肪组织中脂蛋白脂肪酶（LPL）和激素敏感脂肪酶（HSL）的活性。PPAR-γ和TNF-α mRNA水平在妊娠和产后保持不变。DNA阶梯和原位染色均未检测到细胞凋亡。LPL活性在妊娠第5天显著升高，并持续升高至妊娠第14天。HSL活性在妊娠第10天显著升高，在分娩后、哺乳第10天显著降低。综上所述，在大鼠妊娠和产后期间，母体脂肪量的变化与PPAR-γ和TNF-α mRNA的表达水平无直接相关性。细胞凋亡似乎也不影响脂肪量的变化。妊娠期间LPL和HSL活性的变化提示这些酶可能是母体脂肪组织水平的调节因子。

Dramatic alternations in maternal metabolism occur during gestation and lactation, especially glucose and fat metabolism. For example, in rats, the amount of body fat mass increases during gestation, then decreases just prior to delivery, and remains low after parturition. To investigate the factors involved in such changes in maternal fat mass, messenger ribonucleic acid (mRNA) levels of adipocytokines, peroxisome proliferator-activated receptor-γ (PPAR-γ) and tumor necrosis factor-α (TNF-α), were examined in the intraabdominal adipose tissue of non-pregnant rats, pregnant rats and postpartum rats. We also examined the issue of whether apoptosis, which could be promoted by PPAR-γ and TNF-α, is involved in any of the changes in maternal fat mass. The activity of lipoprotein lipase (LPL) and hormone sensitive lipase (HSL) in adipose tissue was also measured. PPAR-γ and TNF-α mRNA levels remained constant during the gestational and postpartum periods. Apoptosis was not detected at any time as evidenced by DNA laddering and in situ staining. LPL activity was significantly increased at day 5 and remained elevated until day 14 of gestation. HSL activity was significantly increased at day 10 of gestation and then decreased after delivery, at day 10 of lactation.In conclusion, during the gestational and postpartum period of rats, changes in maternal fat mass did not directly correlate with the levels of expression of PPAR-γ and TNF-α mRNA. Apoptosis also does not appear to influence on fat mass change. The changes in LPL and HSL activities during gestation suggest that these enzymes might be regulators of maternal adipose tissue level.