Rodriguez de Turco E B, Spitzer J A
Department of Physiology, Louisiana State University Medical Center, New Orleans 70112.
Biochem Biophys Res Commun. 1988 Aug 30;155(1):151-9. doi: 10.1016/s0006-291x(88)81062-3.
The turnover of vasopressin-stimulated 32P-phosphoinositides and 32P-phosphatidic acid and accumulation of [2-3H]-inositol phosphates were examined in hepatocytes from rats infused i.v. with saline and E. coli endotoxin for 3 hrs. Within 60s of VP stimulation the decrease in phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate labeling as well as the increased uptake of 32P into phosphatidic acid were similar in both groups. However, at a later time (300s) the 32P-phosphatidylinositol turnover was greatly decreased concomitantly with a higher labeling of phosphatidic acid. The accumulation of [2-3H]-inositol phosphates in ET-cells was significantly decreased both at 30s and 600s after VP addition. The distribution of [2-3H]-inositol labeling accumulated in the different inositol phosphate fractions over the first 30s of VP stimulation showed a tendency to lower accumulation of inositol trisphosphate, and a significantly lower accumulation of inositol bisphosphate simultaneously with a higher labeling of the inositol tetrakisphosphate fraction. These observations reflect an early effect of ET-infusion on VP-stimulated inositol lipid turnover and on the subsequent metabolism of the released inositol phosphates.
通过静脉注射生理盐水和大肠杆菌内毒素3小时，检测大鼠肝细胞中血管加压素刺激的32P - 磷酸肌醇和32P - 磷脂酸的周转率以及[2 - 3H] - 肌醇磷酸的积累。在血管加压素刺激的60秒内，两组中磷脂酰肌醇4 - 磷酸和磷脂酰肌醇4,5 - 二磷酸标记的减少以及32P进入磷脂酸的摄取增加相似。然而，在稍后的时间（300秒），32P - 磷脂酰肌醇周转率大大降低，同时磷脂酸标记更高。添加血管加压素后30秒和600秒时，内毒素处理细胞中[2 - 3H] - 肌醇磷酸的积累均显著降低。在血管加压素刺激的前30秒内，积累在不同肌醇磷酸组分中的[2 - 3H] - 肌醇标记分布显示，肌醇三磷酸积累有降低趋势，肌醇二磷酸积累显著降低，同时肌醇四磷酸组分标记更高。这些观察结果反映了内毒素输注对血管加压素刺激的肌醇脂质周转率以及随后释放的肌醇磷酸代谢的早期影响。
