LOW-TEMPERATURE SLOWING AND COLD-BLOCK OF FAST AXOPLASMIC-TRANSPORT IN MAMMALIAN NERVES INVITRO
LOW-TEMPERATURE SLOWING AND COLD-BLOCK OF FAST AXOPLASMIC-TRANSPORT IN MAMMALIAN NERVES INVITRO
复制标题
DOI：
10.1002/neu.480060112
复制
发表时间：
1975-01-01
期刊：
影响因子：
--
通讯作者：
SMITH, C
中科院分区：
文献类型：
--
作者：
OCHS, S;SMITH, C
1)利用同位素标记技术研究了哺乳动物体外神经血管的快速轴浆转运。温度低于38°C时，体外培养的猫坐骨神经纤维流出率为410 mm/d， 38 - 18°C时aq10为2.0,38 - 13°C时aq10为2.3。2)温度为11°C时，发生部分运输失败。在低于11°C的温度下，发生了快速轴浆运输的完全阻塞，这种现象称为“冷阻塞”。在10-0°C的温度范围内，在长达48小时的时间内，根本没有观察到任何运输。3)经过长达22小时的低温阻滞后，神经恢复到38°C的温度。在恢复阶段可以看到由于冷阻引起的一些有害影响，如波峰幅度的减少、波峰形式的改变和速率的减慢。4)在低温或冷阻温度下保存64小时的神经中，~ P水平（ATP和磷酸肌酸的组合）保持在接近控制水平。因此，在长达22小时的低温下，快速轴浆运输速率的降低被认为是由于ATP利用率的降低，这一概念与为解释快速轴浆运输而提出的“运输丝”模型一致。5)在18-13°C的温度范围内，峰前的倾斜表明在较低的温度下有一个额外的因素。讨论了微管的解体作为冷块现象的可能解释。
1) Fast axoplasmic transport in mammalian nervein vitrowas studied using an isotope labeling technique. The rate of outflow in cat sciatic nerve fibers of 410 mm/dayin vitrowas reduced at temperatures below 38°C with aQ10of 2.0 in the range 38–18°C and aQ10of 2.3 at 38–13°C.2) At a temperature of 11°C a partial failure of transport occurred. At temperatures below 11°C a complete block of fast axoplasmic transport occurred, a phenomenon termed “cold‐block.” No transport at all was seen over the temperature range of 10–0°C for times lasting up to 48 hr.3) Transport was resumed after a period of cold‐block lasting up to 22 hr when the nerves were brought back to a temperature of 38°C. Some deleterious effects due to cold‐block were seen in the recovery phase as indicated by a reduction in crest amplitude, change in its form, and slowed rate.4) The ∼P level (combined ATP and creatine phosphate) remained near control level in nerves kept at low or cold‐block temperatures for times as long as 64 hr. The reduction in fast axoplasmic transport rate seen at low temperatures for times up to 22 hr was therefore considered due to a decrease in the utilization of ATP, a concept in accord with the “transport filament” model proposed to account for fast axoplasmic transport.5) The sloping of the front of the crest over the temperature range of 18–13°C suggests an additonal factor at the lower temperatures. A disassembly of microtubules is discussed as a possible explanation of the cold‐block phenomenon.