注射到小鼠中脑导水管周围灰质区域的吗啡的应变依赖性效应。

Strain-dependent effects of morphine injected into the periaqueductal gray area of mice.

Nunes-de-Souza R L, Graeff F G, Siegfried B

Laboratório de Psicobiologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Brasil.

Braz J Med Biol Res. 1991;24(3):291-9.

Abstract

Microinjection of morphine (0.31, 1.25 and 5.0 micrograms) into the periaqueductal grey area (PAG) of C57BL/6 (C57) and DBA/2 (DBA) mice increased the pain threshold in the tail-flick test. The highest dose also caused a behavioral reaction in both strains characterized by periods of immobility alternating with explosive motor behavior. 2. In the DBA strain, the analgesic effect was demonstrated with all doses of morphine, while in the C57 strain only the highest dose induced analgesia. 3. DBA mice presented a decrease in activity with the lowest dose of morphine, whereas in the C57 strain, this effect was obtained only with the highest dose of morphine. 4. These data corroborate at the PAG level the results of other studies which have shown that central and peripheral injections of morphine produce analgesia and alter motor activity in C57 and DBA strains. They also confirm that these two strains of mice present genotype-dependent differences in sensitivity to opioids as determined after injections of morphine into the PAG.

摘要

向C57BL/6（C57）和DBA/2（DBA）小鼠的导水管周围灰质区域（PAG）微量注射吗啡（0.31、1.25和5.0微克）可提高甩尾试验中的痛阈。最高剂量还在两种品系中引起一种行为反应，其特征为静止期与爆发性运动行为交替出现。2. 在DBA品系中，所有剂量的吗啡均表现出镇痛作用，而在C57品系中，只有最高剂量诱导出镇痛效果。3. DBA小鼠在最低剂量吗啡作用下活动减少，而在C57品系中，仅在最高剂量吗啡作用下才出现这种效果。4. 这些数据在PAG水平上证实了其他研究的结果，这些研究表明，在C57和DBA品系中，中枢和外周注射吗啡均可产生镇痛作用并改变运动活性。它们还证实，在向PAG注射吗啡后确定，这两种品系的小鼠对阿片类药物的敏感性存在基因型依赖性差异。