Age-related levels of GABA/benzodiazepine binding sites in cerebrum of F-344 rats: effects of exercise.
Age-related levels of GABA/benzodiazepine binding sites in cerebrum of F-344 rats: effects of exercise.
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F-344 大鼠大脑中 GABA/苯二氮卓结合位点的年龄相关水平：运动的影响。
DOI：
10.1016/0197-4580(94)00158-8
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发表时间：
1995
影响因子：
4.2
通讯作者：
al-Dahan,MI
中科院分区：
文献类型：
--
作者：
Tehrani,MH;Tate,CA;al-Dahan,MI
我们检查了近交 Fischer 344 雄性大鼠脑膜中的 γ-氨基丁酸 (GABA)、苯二氮卓类药物和突触后 GABA/苯二氮卓类受体 (GBZR) 的惊厥位点与年龄的关系。在老年大鼠（23至24个月）中，[3H]氟硝西泮测定的苯二氮卓结合位点分别比年轻成年（3至4个月）和成熟（10至12个月）大鼠的相应值低47%和43%。减少是由于结合密度的损失而不是亲和力的变化。当使用 5 nM 或 40 nM 标记的蕈醇时，[3H]蕈醇结合没有观察到与年龄相关的统计学显着变化。 GABA 对所有年龄组的氟硝西泮结合产生剂量依赖性刺激，但老年动物的最大刺激显着高于年轻和成熟动物 (24%)。 [35S]TBPS 结合位点（GABA/苯二氮卓受体的惊厥位点）不受年龄影响。我们还研究了运动对老年大鼠 GBZR 结合位点的影响。老年动物中氟硝西泮结合位点的下降以及氟硝西泮对 GABA 调节的高敏感性通过 8 至 10 周的耐力运动得以逆转。耐力运动对蝇蕈醇或 TMPS 结合位点没有任何显着影响。结果表明，GBZR 结合位点存在与年龄相关的改变，并且这些改变可以通过运动逆转。
We examined γ-aminobutyric acid (GABA), benzodiazepine and convulsant sites of postsynaptic GABA/benzodiazepine receptors (GBZR) in cerebral membranes of inbred Fischer 344 male rats as a function of age. In aged rats (23 to 24 months), the benzodiazepine binding site as determined by [3H]flunitrazepam was 47% and 43% lower than corresponding values in young adult (3 to 4 months) and mature (10 to 12 months) rats, respectively. The decrease was due to the loss of binding density rather than a change in affinity. No statistically significant age-related changes in [3H]muscimol binding were observed when 5 nM or 40 nM labeled muscimol were used. GABA produced a dose-dependent stimulation of flunitrazepam binding in all age groups, but the maximum stimulation in aged animals was significantly higher (24%) than in young and mature animals. The [35S]TBPS binding site, the convulsant site of GABA/benzodiazepine receptors, was unaffected with age. We also studied the effects of exercise on GBZR binding sites of aged rats. The decline of flunitrazepam binding sites and the high sensitivity of flunitrazepam binding to regulation by GABA in aged animals were reversed by 8 to 10 weeks of endurance exercise. Endurance exercise did not have any significant effect on muscimol or TMPS binding sites. Results suggest that there are aged-related alterations of GBZR binding sites and that these modifications can be reversed by exercise.