Goldberg D M, Roomi M W, Yu A
Enzyme. 1983;30(1):59-65. doi: 10.1159/000469546.
Hepatic microsomal phosphatidate phosphohydrolase (PPH) showed minor fluctuations with age in male and female rats. In males, hepatic cytosolic PPH rose to a peak at day 58 and then declined. In female rats, the activities of this enzyme were much lower than those of the male to day 35, but then increased fivefold by day 50 to values approximating those of males, and thereafter gradually declined. The hepatic triacylglycerol (TG) content of male rats was fairly constant, but in females the values rose to a peak on day 50 and then declined in parallel with the cytosolic PPH activity, but remained substantially higher than values for male rats. A significant correlation between cytosolic PPH and hepatic TG was obtained. The microsomal PPH did not correlate with hepatic TG. These results suggest that in the rat cytosolic PPH may play a role in modulating age-related changes in hepatic TG metabolism, and that it is functionally more important than the microsomal enzyme in this species.
肝微粒体磷脂酸磷酸水解酶（PPH）在雄性和雌性大鼠中随年龄有轻微波动。在雄性大鼠中，肝细胞溶质PPH在第58天升至峰值，然后下降。在雌性大鼠中，该酶的活性在第35天之前远低于雄性大鼠，但到第50天增加了五倍，达到接近雄性大鼠的值，此后逐渐下降。雄性大鼠的肝脏三酰甘油（TG）含量相当恒定，但在雌性大鼠中，该值在第50天升至峰值，然后与细胞溶质PPH活性平行下降，但仍显著高于雄性大鼠的值。细胞溶质PPH与肝脏TG之间存在显著相关性。微粒体PPH与肝脏TG不相关。这些结果表明，在大鼠中，细胞溶质PPH可能在调节肝脏TG代谢的年龄相关变化中起作用，并且在该物种中其功能比微粒体酶更重要。
