Berge O G, Fasmer O B, Flatmark T, Hole K
Pharmacol Biochem Behav. 1983 Apr;18(4):637-43. doi: 10.1016/0091-3057(83)90293-9.
Intrathecal injection of 5,6-dihydroxytryptamine (5,6-DHT) in rats produced selective lesions of the descending 5-HT pathways. Spinal 5-HT levels gradually fell to less than 10% of controls within 10 days of 5,6-DHT administration with no recovery evident within 4 weeks. The uptake of 14C-5-HT into crude spinal synaptosomes was similarly reduced. The uptake of 3H-NA into spinal synaptosomes was unaffected, as was the uptake of 14C-5-HT and 3H-NA into cortical synaptosomes. Following 5,6-DHT, tail-flick latencies were reduced by 20-30% during the first post-injection week, but returned to control levels during the second week. Intrathecal or systemic administration of the 5-HT receptor antagonist metergoline significantly reduced latencies of normal rats and of 5,6-DHT treated rats tested after the second week when the response was normalized. Metergoline did not, however, further reduce the latencies of lesioned rats during the first post-injection week. It is concluded that functional adaptation involving 5-HT neurotransmission compensated for the selective lesion of descending 5-HT pathways induced by 5,6-DHT.
向大鼠鞘内注射5,6 - 二羟基色胺（5,6 - DHT）可导致下行5 - 羟色胺（5 - HT）通路的选择性损伤。在给予5,6 - DHT后的10天内，脊髓5 - HT水平逐渐降至对照组的10%以下，且在4周内未见明显恢复。14C - 5 - HT进入粗制脊髓突触体的摄取同样减少。3H - 去甲肾上腺素（NA）进入脊髓突触体的摄取未受影响，14C - 5 - HT和3H - NA进入皮质突触体的摄取也未受影响。注射5,6 - DHT后，在注射后的第一周内甩尾潜伏期缩短了20 - 30%，但在第二周恢复到对照水平。鞘内或全身给予5 - HT受体拮抗剂美替拉酮可显著缩短正常大鼠以及在第二周测试时反应已恢复正常的5,6 - DHT处理大鼠的潜伏期。然而，在注射后的第一周，美替拉酮并未进一步缩短损伤大鼠的潜伏期。结论是，涉及5 - HT神经传递的功能适应性补偿了由5,6 - DHT诱导的下行5 - HT通路的选择性损伤。
