INCREASED RESPONSIVENESS OF SENSORY NEURONS IN THE SAPHENOUS NERVE OF THE STREPTOZOTOCIN-DIABETIC RAT
INCREASED RESPONSIVENESS OF SENSORY NEURONS IN THE SAPHENOUS NERVE OF THE STREPTOZOTOCIN-DIABETIC RAT
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DOI：
10.1152/jn.1992.68.6.2077
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发表时间：
1992-12-01
影响因子：
2.5
通讯作者：
LEVINE, JD
中科院分区：
文献类型：
--
作者：
AHLGREN, SC;WHITE, DM;LEVINE, JD
1. 本研究观察了链脲佐菌素诱导大鼠糖尿病（STZ-D）后隐神经感觉神经元的变化。STZ-D大鼠感觉神经元的一些生理特性，包括全神经自发活动的百分比和率以及单个c -纤维的机械和热阈值，与对照（CON）大鼠相比无显著差异。STZ-D和CON - c纤维对持续（1 min）阈值力机械刺激的响应相似。然而，在移除刺激后的5分钟内，STZ-D大鼠出现了更大的后放电（STZ-D: n = 35; 14.6 +/- 5.1动作电位/5分钟，平均+/- SE； CON: n = 34; 3.9 +/- 0.7动作电位/5分钟）。持续（1 min）阈上机械刺激（445 g）时，STZ-D大鼠c -纤维的动作电位数量也显著增加（STZ-D: n = 44; 149.7 +/- 18.4个动作电位；CON: n = 45; 84.7 +/- 12.2个动作电位）。STZ-D大鼠c -纤维在去除持续阈上刺激后5分钟内的后放电也更大（STZ-D: 38.7 +/- 13.1个动作电位/5 min； CON: 9.3 +/- 2.3个动作电位/5 min）。STZ-D大鼠与对照大鼠的c -纤维在某些感觉类别上的分布有显著差异。因此，机械和热不敏感的c -纤维在CON大鼠中所占比例为12%，而在STZ-D大鼠中仅为5%；对冷（c -冷和c -机械冷）的反应比例从对照组的9%增加到STZ-D组的19%。对机械刺激的反应比例没有变化。STZ-D大鼠Adelta纤维力学阈值降低（STZ-D: n = 26, 8.1 +/- 3.5 g; CON: n = 28, 29.2 +/- 10.2 g）。在感觉类方面，Adelta纤维种群的分布没有变化。总之，目前的数据表明，c纤维伤害感受器的反应性增加和延长可能有助于糖尿病大鼠行为研究中报道的机械伤害阈值降低。Adelta机械阈值的降低也可能起作用。我们没有发现糖尿病大鼠损伤感觉改变与β纤维变化有关的证据。
1. This study examined sensory neurons in the saphenous nerve of rats treated with streptozotocin to induce diabetes (STZ-D). Several physiological properties of sensory neurons were not significantly different in STZ-D compared with control (CON) rats, including percentage and rate of spontaneous activity seen in the whole nerve and mechanical and thermal thresholds of individual C-fibers.2. The response of STZ-D and CON C-fibers to a sustained (1 min) mechanical stimulus of threshold force was similar. However, during the 5 min immediately after removal of this stimulus, there was a much greater afterdischarge in STZ-D rats (STZ-D: n = 35; 14.6 +/- 5.1 action potentials/ 5 min, mean +/- SE; CON: n = 34; 3.9 +/- 0.7 action potentials/5 min). The number of action potentials during a sustained (1 min) suprathreshold mechanical (445 g) stimulus was also significantly greater in the C-fibers from STZ-D rats (STZ-D: n = 44; 149.7 +/- 18.4 action potentials; CON: n = 45; 84.7 +/- 12.2 action potentials). The afterdischarge during the 5 min immediately after removal of the sustained suprathreshold stimulus was also greater in C-fibers from STZ-D rats (STZ-D: 38.7 +/- 13.1 action potentials/5 min; CON: 9.3 +/- 2.3 action potentials/5 min).3. There was a significant difference between C-fibers from STZ-D and CON rats with respect to the distribution among certain sensory classes. Thus the proportion of mechanically and thermally insensitive C-fibers was 12% in CON rats but only 5% in STZ-D rats; the proportion responding to cold (C-cold and C-mechanocold) increased from 9% in CON rats to 19% in STZ-D rats. The proportion responding to mechanical stimuli did not change.4. The mechanical threshold of Adelta fibers was decreased in STZ-D rats (STZ-D: n = 26, 8.1 +/- 3.5 g; CON: n = 28, 29.2 +/- 10.2 g). There was no change in the distribution of the Adelta fiber population with respect to sensory class.5. In conclusion, the present data suggest that an increased and prolonged responsiveness of C-fiber nociceptors may contribute to the lowered mechanical nociceptive threshold reported in behavioral studies of diabetic rats. A decrease in Adelta mechanical threshold may also contribute. We found no evidence for a contribution of changes in Abeta fibers to altered nociception in the diabetic rat.