Marriott D R, Wilkin G P
Department of Biochemistry, Imperial College of Science, Technology and Medicine, London, England.
J Neurochem. 1992 Aug;59(2):443-8. doi: 10.1111/j.1471-4159.1992.tb09390.x.
In this study we have investigated the effects of preincubation of cultured astrocytes with substance P (SP) on subsequent 125I-Bolton-Hunter conjugated SP (125I-BHSP) receptor binding, and SP-stimulated phosphatidyl-inositol (PI) accumulation. Spinal cord astrocytes preincubated for up to 96 h with SP (0.001-1,000 nM) suffered a dose-dependent decrease in both subsequent 125I-BHSP and SP-stimulated PI turnover. In contrast, preincubation of cerebellar astrocytes with SP resulted in an increase in SP-stimulated PI turnover, with no change in 125I-BHSP receptor binding. SP-induced PI turnover in cerebellar astrocytes was maximal after 72 h of preincubation with 0.1 nM SP. These data suggest that increased coupling between receptor and second messenger occurs in response to chronic exposure to SP.
在本研究中，我们研究了用P物质（SP）预孵育培养的星形胶质细胞对随后的125I-博尔顿-亨特偶联SP（125I-BHSP）受体结合以及SP刺激的磷脂酰肌醇（PI）积累的影响。用SP（0.001 - 1000 nM）预孵育长达96小时的脊髓星形胶质细胞，随后的125I-BHSP和SP刺激的PI周转率均呈剂量依赖性降低。相反，用SP预孵育小脑星形胶质细胞导致SP刺激的PI周转率增加，而125I-BHSP受体结合没有变化。用0.1 nM SP预孵育72小时后，小脑星形胶质细胞中SP诱导的PI周转率最高。这些数据表明，受体与第二信使之间的偶联增加是对长期暴露于SP的反应。
