INTRACELLULAR CALCIUM OSCILLATION IN LHRH CELLS FROM EMBRYONIC OLFACTORY PLACODE

目的了解促性腺激素释放激素(LHRH)脉动释放的机制。 以及培养的LHRH神经元是否表现出自发的细胞内 Ca~(2+)([Ca~(2+)]i)信号。嗅觉定位器和腹侧 E35-37期恒河猴胚胎LHRH神经元的迁移途径 被解剖出来并在玻璃盖子上培养。两到五周 后来培养的细胞被钙染料Fura-2标记，并 通过记录[Ca~(2+)]i的变化来检查[Ca~(2+)]i信号 S 10分钟，30-175分钟。细胞固定，LHRH和LHRH免疫组化染色 神经元特异性烯醇化酶。在20代培养中，572个LHRH阳性细胞 在脉冲间隔(IPI)为 8.2(0.7min)，持续时间88.8(2.9 S)。 培养上清液中仅偶尔出现[Ca~(2+)]_i振荡。在20年中的第17年 与LHRH阳性细胞培养时，出现[Ca~(2+)]i振荡 在50%-100%的单个细胞中同步，而[Ca~(2+)]i 其余3种培养物中的细胞振荡不同步。 引人注目的是，在17种培养物中，有12种细胞的[Ca~(2+)]i同步 在52.8(3.0分钟)时完全一致地反复发生振荡 间期，与观察到的LHRH释放周期相似， 而在17个培养中的5个中，[Ca~(2+)]i的同步性不那么紧密 振荡在23.4(4.6分钟间隔)重复发生。的IPI 具有紧密同步性和较少同步性的细胞内[Ca~(2+)]i振荡 紧密同步与单元格中的IPI没有什么不同 同步。结果表明，LHRH神经元来源于 猴子嗅觉定位具有一种内源性机制 [Ca~(2+)]_i振荡同步。未来的方向，我们将 确定[Ca~(2+)]_i振荡是否同步 周期性的LHRH神经分泌物。关键词细胞内钙离子 信号、细胞内钙振荡、同步化、LHRH 神经元，嗅觉定位器。资助NIH HD15433和RR00167 脉动性LHRH的细胞机制 放手。上将薪酬内分泌激素。112 283-295,1998。(J)

OBJECTIVE To understand the mechanism of pulsatile LHRH release, and whether cultured LHRH neurons exhibit spontaneous intracellular Ca2+ ([Ca2+]i) signaling. The olfactory placode and the ventral migratory pathway of LHRH neurons from rhesus monkey embryos at E35-37 were dissected out and cultured on glass coverslips. Two to 5 weeks later cultured cells were labeled with the calcium dye, fura-2, and examined for [Ca2+]i signaling by recording changes in [Ca2+]i every 10 s for 30-175 min. Cells were fixed and immunostained for LHRH and neuron specific enolase. In 20 cultures, 572 LHRH-positive cells exhibited [Ca2+]i oscillations at an interpulse interval (IPI) of 8.2(0.7 min, and a duration of 88.8(2.9 s. LHRH-negative neurons in culture exhibited only occasional [Ca2+]i oscillations. In 17 of 20 cultures with LHRH-positive cells, [Ca2+]i oscillations occurred synchronously in 50-100% of the individual cells, whereas [Ca2+]i oscillations in cells in the remaining 3 cultures did not synchronize. Strikingly, in 12 of 17 cultures the synchronization of [Ca2+]i oscillations repeatedly occurred in complete unison at 52.8(3.0 min intervals, which is similar to the period observed for LHRH release, whereas in 5 of 17 cultures the less tight synchronization of [Ca2+]i oscillations repeatedly occurred at 23.4(4.6 min intervals. IPI of [Ca2+]i oscillations in cells with tight synchronization and less tight synchronization did not differ from IPI in cells without synchronization. The results indicate that LHRH neurons derived from the monkey olfactory placode possess an endogenous mechanism for synchronization of [Ca2+]i oscillations. FUTURE DIRECTIONS We will determine if synchronization of [Ca2+]i oscillations is manifestation of periodical LHRH neurosecretion. KEY WORDS intracellular Ca2+ signaling, intracellular Ca2+ oscillations, synchronization, LHRH neurons, olfactory placode. FUNDING NIH HD15433 & RR00167 PUBLICATIONS Terasawa, E. Cellular mechanism of pulsatile LHRH release. Gen. Comp. Endocrinol. 112 283-295, 1998. (J)