Foster M C, Castiglia C M, Saubermann A J
Department of Anesthesiology, School of Medicine, SUNY, Stony Brook 11794-8480.
Brain Res. 1992 Dec 4;597(2):181-8. doi: 10.1016/0006-8993(92)91473-r.
Effects of serotonin (5-HT) and carbachol on Rb uptake (used as a K marker) in leech neuron and glia were studied by electron probe microanalysis (EPMA). Hirudo medicinalis ganglia were perfused 60 s in 4 mM Rb substituted normal leech Ringer's with and without 5-HT (dosage range 5-500 microM) or carbachol (range 10-1000 microM), quench frozen cryosectioned, and subjected to EPMA to determine elemental mass fractions and cell water content. Both 5-HT and carbachol altered leech neuron and glial cell elemental distribution and water content. In glial cells, a dose-dependent increase in Rb uptake was observed following 5-HT (control: 26 +/- 2 microM; 5 microM: 47 +/- 4; 50 microM: 62 +/- 4; 500 microM: 82 +/- 11 mmol/kg dry wt. +/- S.E.M.) and carbachol (10 microM: 35 +/- 3; 100 microM: 52 +/- 3; 1000 microM: 68 +/- 3 mmol/kg dry wt. +/- S.E.M.). In neurons, 5-HT and carbachol had small effects. 5-HT decreased glial and neuronal cell water content. Carbachol decreased neuronal (but not glial) water content by approximately the same amount (mean decrease 9%) regardless of dose. Both 5-HT and carbachol affected glial cell K-accumulating properties, providing evidence that certain neurotransmitters may modulate invertebrate glial cells' K clearance function.
通过电子探针微量分析（EPMA）研究了血清素（5-羟色胺，5-HT）和卡巴胆碱对水蛭神经元和神经胶质细胞中铷摄取（用作钾标记物）的影响。用含和不含5-HT（剂量范围为5-500微摩尔）或卡巴胆碱（范围为10-1000微摩尔）的4毫摩尔铷替代正常水蛭林格液灌注药用蛭神经节60秒，骤冷冷冻切片，然后进行EPMA以确定元素质量分数和细胞含水量。5-HT和卡巴胆碱均改变了水蛭神经元和神经胶质细胞的元素分布及含水量。在神经胶质细胞中，5-HT（对照组：26±2微摩尔；5微摩尔：47±4；50微摩尔：62±4；500微摩尔：82±11毫摩尔/千克干重±标准误）和卡巴胆碱（10微摩尔：35±3；100微摩尔：52±3；1000微摩尔：68±3毫摩尔/千克干重±标准误）作用后观察到铷摄取呈剂量依赖性增加。在神经元中，5-HT和卡巴胆碱的作用较小。5-HT降低了神经胶质细胞和神经元细胞的含水量。卡巴胆碱无论剂量如何，均使神经元（而非神经胶质细胞）含水量降低约相同幅度（平均降低9%）。5-HT和卡巴胆碱均影响神经胶质细胞的钾积累特性，这表明某些神经递质可能调节无脊椎动物神经胶质细胞的钾清除功能。
