Allen C U, Janzen W P, Granger N A
Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599.
Mol Cell Endocrinol. 1992 Apr;84(3):227-41. doi: 10.1016/0303-7207(92)90034-4.
The effect of altering intracellular free Ca2+ on juvenile hormone (JH) and acid synthesis by larval and pupally-committed corpora allata (CA) of fifth stadium Manduca sexta was investigated. Larval CA required extracellular Ca2+ greater than or equal to 0.1 mM for maximal JH synthesis, while JH acid synthesis by glands after pupal commitment was independent of extracellular Ca2+. Free Ca2+ in the hemolymph ranged from 1.4 to 2.1 mM during the fifth stadium. Both calcium ionophores and caffeine, which releases Ca2+ from intracellular stores, inhibited JH synthesis by larval CA but stimulated JH acid synthesis by post-commitment CA. These results suggest that intracellular stores may be the principal source of Ca2+ for the biosynthetic activity of the post-commitment gland. Calcium channel blockers (La3+, Cd2+) and antagonists (verapamil, isradipine and nitrendipine) decreased both JH and JH acid synthesis, indicating the existence of Ca2+ channels in the CA cell membrane. Calmodulin (CaM) antagonists inhibited the activity of both larval and post-commitment CA, suggesting an integral relationship of CaM to the effects of Ca2+ on gland activity. One of these effects is the demonstrated requirement of 0.1 mM extracellular Ca2+ for allatostatin inhibition of JH I synthesis by larval CA.
研究了改变细胞内游离钙离子（Ca2+）对烟草天蛾五龄幼虫和蛹期咽下神经节（CA）合成保幼激素（JH）及酸的影响。幼虫CA合成最大量JH需要细胞外Ca2+浓度大于或等于0.1 mM，而蛹期咽下神经节合成JH酸则与细胞外Ca2+无关。五龄期血淋巴中游离Ca2+浓度范围为1.4至2.1 mM。钙离子载体和咖啡因（从细胞内储存释放Ca2+）均抑制幼虫CA合成JH，但刺激蛹期咽下神经节后合成JH酸。这些结果表明，细胞内储存可能是蛹期咽下神经节生物合成活动中Ca2+的主要来源。钙通道阻滞剂（La3+、Cd2+）和拮抗剂（维拉帕米、伊拉地平、尼群地平）均降低JH和JH酸的合成，表明CA细胞膜中存在Ca2+通道。钙调蛋白（CaM）拮抗剂抑制幼虫和蛹期咽下神经节的活性，表明CaM与Ca2+对腺体活性的影响存在内在联系。其中一个影响是，已证明幼虫CA合成JH I受咽侧体抑制素抑制需要0.1 mM细胞外Ca2+。
