Keller E A, Cancela L M, Molina V A, Orsingher O A
Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Pharmacol Biochem Behav. 1994 Apr;47(4):789-93. doi: 10.1016/0091-3057(94)90278-x.
The reactivity of 5-HT receptors following repeated immobilization sessions or after immobilization plus morphine was measured through 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) or 8-hydroxy-2-(dipropyl-amino)tetralin (8-OH-DPAT)-induced serotonergic syndrome in adult rats undernourished at perinatal age. Repeated stress enhanced the scores of forepaw treading and hindlimb abduction elicited by 5-MeODMT in control animals. In a similar way, forepaw treading induced by 8-OH-DPAT was enhanced in chronically stressed control rats. These results indicate the development of supersensitivity in 5-HT1 receptors. Conversely, this effect was not observed in undernourished animals. Morphine injections before each stress session instaured the increased reactivity to 5-HT1 sites in malnourished animals. An injection of naloxone prior to morphine before each stress session fully antagonized the increased behavioral reactivity to 5-MeODMT observed in deprived animals. A possible deficiency in the functional role of the opiate system involved in the process of adaptation to chronic stress in early undernourished rats is suggested.
在围产期营养不良的成年大鼠中，通过5-甲氧基-N，N-二甲基色胺（5-MeODMT）或8-羟基-2-（二丙基氨基）四氢萘（8-OH-DPAT）诱导的血清素能综合征，来测量重复固定疗程后或固定加吗啡处理后5-羟色胺（5-HT）受体的反应性。重复应激增强了5-MeODMT在对照动物中引起的前爪踩踏和后肢外展的评分。同样，在慢性应激的对照大鼠中，8-OH-DPAT诱导的前爪踩踏也增强了。这些结果表明5-HT1受体出现了超敏反应。相反，在营养不良的动物中未观察到这种效应。在每次应激疗程前注射吗啡，可使营养不良动物对5-HT1位点的反应性增加。在每次应激疗程前，在注射吗啡前先注射纳洛酮，可完全拮抗在营养不良动物中观察到的对5-MeODMT行为反应性的增加。这表明早期营养不良大鼠在适应慢性应激过程中，阿片系统的功能作用可能存在缺陷。
