Koganezawa Masayuki, Shimada Ichiro
Biological Institute, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
J Neurobiol. 2002 Apr;51(1):66-83. doi: 10.1002/neu.10047.
The role of an inositol 1,4,5-trisphosphate (IP3)-mediated transduction cascade in the response of taste receptor cells of the fleshfly Boettcherisca peregrina was investigated by using the following reagents: neomycin (an inhibitor of IP3 production), U73122 (an inhibitor of phospholipase C), adenophostin A (an agonist of the IP3-gated channel), IP3, ruthenium red (a blocker of the IP3-gated channel), and 2-aminoethoxydiphenylborate (2-APB; an antagonist of the IP3-gated channel). For introduction into the receptor cell, the reagents were mixed with a detergent, deoxycholate (DOC). After treatment with neomycin + DOC or U73122 + DOC, the response of the sugar receptor cell to sugars was depressed compared with responses after treatment with DOC alone. During the treatment of adenophostin A + DOC, the response of the sugar receptor cell was elicited. After treatment with IP3 + DOC, the response of the sugar receptor cell to sugars and to amino acids was apparently enhanced. When taste stimuli were administered in the presence of ruthenium red or 2-APB, the response of the sugar receptor cell to glucose were inhibited. The expression of genes for substances involved in the IP3 transduction cascade, such as G protein alpha subunit (dGqalpha), phospholipase C (norpA), and IP3 receptor (itpr), were examined in the taste receptor cell of the fruitfly Drosophila melanogaster by using the pox-neuro70 mutant (poxn70), which lacks taste receptor cells. The expressed levels of dGqalpha and itpr in the tarsus of poxn70 mutant flies were reduced compared with those of wild-type flies. These results suggest that the IP3 transduction cascade is involved in the response of the sugar receptor cell of the fly.
通过使用以下试剂，研究了肌醇1,4,5 - 三磷酸（IP3）介导的转导级联在肉蝇Boettcherisca peregrina味觉受体细胞反应中的作用：新霉素（IP3产生的抑制剂）、U73122（磷脂酶C的抑制剂）、腺嘌呤霉素A（IP3门控通道的激动剂）、IP3）、钌红（IP3门控通道的阻滞剂）和2 - 氨基乙氧基二苯硼酸盐（2 - APB；IP3门控通道的拮抗剂）。为了将试剂引入受体细胞，将它们与去污剂脱氧胆酸盐（DOC）混合。用新霉素+ DOC或U73122 + DOC处理后，与仅用DOC处理后的反应相比，糖受体细胞对糖的反应受到抑制。在用腺嘌呤霉素A + DOC处理期间，引发了糖受体细胞的反应。用IP3 + DOC处理后，糖受体细胞对糖和氨基酸的反应明显增强。当在钌红或2 - APB存在下给予味觉刺激时，糖受体细胞对葡萄糖的反应受到抑制。通过使用缺乏味觉受体细胞的痘神经70突变体（poxn70），在果蝇Drosophila melanogaster的味觉受体细胞中检测了参与IP3转导级联的物质的基因表达，如G蛋白α亚基（dGqalpha）、磷脂酶C（norpA）和IP3受体（itpr）。与野生型果蝇相比，poxn70突变体果蝇跗节中dGqalpha和itpr的表达水平降低。这些结果表明IP3转导级联参与了果蝇糖受体细胞的反应。
