Yano K, Nakashima S, Nozawa Y
FEBS Lett. 1983 Sep 19;161(2):296-300. doi: 10.1016/0014-5793(83)81028-x.
Exposure of rabbit neutrophils to formyl-methionyl-leucyl-phenylalanine (FMLP) induced the efflux of 45Ca2+ from pre-labeled cells which was almost complete within 30 s. On the other hand, FMLP-induced 45Ca2+ influx did not become apparent until 60 s after stimulation. When [3H]arachidonic acid-labeled neutrophils were stimulated with FMLP, the radioactivities in phosphatidylinositol 4,5-biphosphate (TPI) and phosphatidylinositol 4-phosphate (DPI) significantly decreased in parallel with the induction of 45Ca2+ efflux. In contrast, degradation of polyphosphoinositides in [3H]glycerol-labeled neutrophils was not significant until 60 s. Taken together, these results indicate that the early degradation of polyphosphoinositides, especially of those rich in arachidonic acid is closely associated with the initial efflux of calcium in FMLP-stimulated rabbit neutrophils. The study of resynthesis of polyphosphoinositides by measuring 32Pi incorporation into these lipids is also presented.
将兔中性粒细胞暴露于甲酰甲硫氨酰亮氨酰苯丙氨酸（FMLP）会诱导预先标记的细胞外流45Ca2+，这在30秒内几乎完成。另一方面，FMLP诱导的45Ca2+内流直到刺激后60秒才明显。当用FMLP刺激[3H]花生四烯酸标记的中性粒细胞时，磷脂酰肌醇4,5-二磷酸（TPI）和磷脂酰肌醇4-磷酸（DPI）中的放射性与45Ca2+外流的诱导同时显著降低。相反，在[3H]甘油标记的中性粒细胞中，多磷酸肌醇的降解直到60秒才显著。综上所述，这些结果表明多磷酸肌醇的早期降解，尤其是富含花生四烯酸的多磷酸肌醇的早期降解与FMLP刺激的兔中性粒细胞中钙的初始外流密切相关。本文还介绍了通过测量32Pi掺入这些脂质来研究多磷酸肌醇再合成的情况。
