DIFFERENTIAL RELEASE OF COEXISTING NEUROTRANSMITTERS - FREQUENCY-DEPENDENCE OF THE EFFLUX OF SUBSTANCE-P, THYROTROPIN RELEASING HORMONE AND [H-3] SEROTONIN FROM TISSUE-SLICES OF RAT VENTRAL SPINAL-CORD
DIFFERENTIAL RELEASE OF COEXISTING NEUROTRANSMITTERS - FREQUENCY-DEPENDENCE OF THE EFFLUX OF SUBSTANCE-P, THYROTROPIN RELEASING HORMONE AND [H-3] SEROTONIN FROM TISSUE-SLICES OF RAT VENTRAL SPINAL-CORD
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DOI：
10.1111/j.1748-1716.1989.tb08721.x
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发表时间：
1989-09-01
期刊：
影响因子：
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通讯作者：
BARTFAI, T
中科院分区：
文献类型：
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作者：
IVERFELDT, K;SERFOZO, P;BARTFAI, T
在少数系统中，对共存的经典神经递质和多肽神经递质的释放进行了研究。本文在灌流系统中观察了大鼠脊髓腹侧组织切片中P物质样免疫反应(SP-LI)、促甲状腺激素释放激素样免疫反应(TRH-LI)和[~3H]-5-羟色胺([~H]-5-HT)的释放。对脑片进行电刺激(900个脉冲，持续时间2ms，36V)，频率在0.25-40 Hz之间。当刺激频率从3~10 Hz改变时，诱发的SP-LI释放分数从0.46增加到1.24%，而TRH-LI的诱发释放分数随着刺激频率的增加从0.28增加到0.71%。当刺激频率在0.25~40赫兹范围内改变时，诱发的[~3H]5-羟色胺释放分数没有明显变化，但仍保持在总组织储备量的5.6%~7.2%之间。在低于0.5-1赫兹的频率下，这些5-羟色胺/SP/TRH神经元可能以5-羟色胺能神经元为主。在3 Hz、900个脉冲刺激下，[~3H]5-羟色胺半最大释放所需的细胞外钙浓度为1.2mmoL·L~(-1)，而SP-Li半最大释放所需的细胞外钙浓度明显较高(4.2mmolL~(-1))。结果表明，P物质、促甲状腺激素释放激素和[~3H]-5-羟色胺共存的神经递质对电刺激的体外释放表现出不同的刺激频率依赖性，提示这些共存神经递质的释放机制至少部分不同。
In few systems has the release of coexisting classical and peptide neurotransmitters been studied. Here the release of substance P-like immunoreactivity (SP-LI), thyrotropin releasing hormone-like immunoreactivity (TRH-LI) and [3H]serotonin ([3H]5-HT) from tissue slices of rat ventral spinal cord was investigated in a superfusion system. The slices were stimulated electrically with field stimulation (900 pulses, a 2 ms duration, 36 V) at frequencies between 0.25 Hz and 40 Hz. The evoked fractional release of SP-LI increased significantly from 0.46 to 1.24% of the total tissue store when the frequency of stimulation was changed from 3 to 10 Hz, while the evoked fractional release of TRH-LI increased significantly from 0.28 to 0.71% of the total tissue store with increasing frequency of stimulation between 0.5 and 3 Hz. The evoked fractional release of [3H]5-HT did not show any significant change when the frequency of stimulation was changed in the frequency range of 0.25-40 Hz but remained between 5.6 and 7.2% of the total tissue store. It appears that at frequencies lower than 0.5-I Hz these 5-HT/SP/TRH neurons may function predominantly as serotonergic neurons. At 3 Hz stimulation with 900 pulses the extracellular Ca2+ concentration required for half-maximal release of [3H]5-HT was 1.2 mmol l-1, while for half-maximal release of SP-LI significantly higher concentrations of Ca2+ (4.2 mmol l-1) would be required. The results demonstrate that the coexisting neurotransmitters substance P, thyrotropin releasing hormone and [3H]serotonin show different dependence on frequency of stimulation for the electrically evoked in-vitro release and suggest that the mechanism of release of these coexisting neurotransmitters is at least partly different.