Nakano T, Taira N
Eur J Pharmacol. 1976 Jul;38(1):23-9. doi: 10.1016/0014-2999(76)90197-7.
Experiments were performed on loosely restrained, conscious dogs in the femoral artery of which a chronic catheter was implanted. All substances were administered through the catheter and vocalization responses to them were used as a principal measure of nociception. In 10 experiments done on 7 dogs, after a single injection of 3 or 10 mumol of 5-hydroxytryptamine, threshold doses (about 0.5 mumol) of acetylcholine for vocalization produced vocalization responses comparable with those to about 3 times threshold doses. In 5 experiments on 5 dogs, after 10 mumol of 5-hydroxytryptamine, threshold doses (about 0.3 nmol) of bradykinin for vocalization produced vocalization responses comparable with those to about twice threshold doses. These doses of 5-hydroxytryptamine produced small vocalization responses in only 3 of the 12 dogs. These results indicate that 5-hydroxytryptamine, although almost devoid of the activity producing noceceptive responses, sensitizes somatic nociceptors for pain-producing substances.
实验在轻度束缚、清醒的犬身上进行，在其股动脉植入慢性导管。所有物质均通过导管给药，对这些物质的发声反应被用作伤害感受的主要测量指标。在对7只犬进行的10次实验中，单次注射3或10 μmol 5-羟色胺后，引起发声的乙酰胆碱阈剂量（约0.5 μmol）产生的发声反应与约3倍阈剂量产生的反应相当。在对5只犬进行的5次实验中，10 μmol 5-羟色胺后，引起发声的缓激肽阈剂量（约0.3 nmol）产生的发声反应与约2倍阈剂量产生的反应相当。这些剂量的5-羟色胺仅在12只犬中的3只引起了小的发声反应。这些结果表明，5-羟色胺虽然几乎没有产生伤害感受性反应的活性，但能使躯体伤害感受器对致痛物质敏感。
