Martínez J A, Aguado M, Frühbeck G
Departamento de Fisiología y Nutrición, Universidad de Navarra, Pamplona, Spain.
J Physiol Biochem. 2000 Mar;56(1):1-8. doi: 10.1007/BF03179770.
Lipid turnover and deposition is under the control of developmental, nutritional, metabolic and neuroendocrine influences. The aim of the current investigations was focused on the study of the involvement of leptin and neuropeptide Y in lipid mobilization. The lipolytic rate was assessed through glycerol release after incubation with leptin and NPY at concentrations ranging from 10(-6) to 10(-12) M in isolated adipocytes obtained from female rats. The presence of leptin at concentrations of 10(-12) to 10(-7) M in the incubation medium of isolated fat cells significantly increased (p < 0.0001) glycerol release, except at the concentration of 10(-11) M, where the increase was (p < 0.01) as compared to the basal lipolytic activity. On the other hand, isolated fat cells of Wistar rats bathed in 10(-10) to 10(-6) M concentrations of NPY demonstrated a statistically significant decrease (p < 0.0001) in glycerol release. At equimolar concentrations of leptin and NPY (10(-12) to 10(-6) M) the observed lipolytic activity is comparable to the basal lipolytic activity, except at a concentration of 10(-9) M where upon a significant increase in lipolysis is observed. A further increase in the equimolar concentrations, beyond 10(-9) M results in a return to the basal lipolytic activity. Summing up, new evidence suggests that NPY and leptin may interact in a homeostatic loop to regulate body-fat mass and energy balance not only at the central nervous system level, but also directly at the adipocyte level.
脂质周转和沉积受发育、营养、代谢及神经内分泌因素的控制。当前研究的目的聚焦于瘦素和神经肽Y在脂质动员中的作用研究。在从雌性大鼠分离得到的脂肪细胞中，将其与浓度范围为10(-6)至10(-12) M的瘦素和神经肽Y孵育后，通过甘油释放来评估脂解速率。在分离脂肪细胞的孵育培养基中，浓度为10(-12)至10(-7) M的瘦素显著增加了甘油释放（p < 0.0001），但10(-11) M浓度除外，与基础脂解活性相比，该浓度下的增加幅度为（p < 0.01）。另一方面，用浓度为10(-10)至10(-6) M的神经肽Y处理的Wistar大鼠分离脂肪细胞，甘油释放量出现了统计学上的显著下降（p < 0.0001）。在瘦素和神经肽Y等摩尔浓度（10(-12)至10(-)(6) M）下，观察到的脂解活性与基础脂解活性相当，但在10(-9) M浓度时，脂解显著增加。等摩尔浓度进一步增加超过10(-9) M时，脂解活性又恢复到基础水平。总之，新证据表明，神经肽Y和瘦素可能在一个稳态循环中相互作用，不仅在中枢神经系统水平，而且直接在脂肪细胞水平调节体脂量和能量平衡。
