Inada K, Yokoi I, Kabuto H, Namba Y, Ogawa N
Department of Neuroscience, Okayama University Medical School, Japan.
Biochem Mol Biol Int. 1997 Apr;41(4):753-65. doi: 10.1080/15216549700201791.
The levels of nitric oxide (NO) and NO synthase (NOS) activities in the brain of young-adult (3 months old), aged (11 months old) and nimodipine-administered (11 months old) senescence-accelerated mouse (SAM), of which SAMP8 sub-strain is inferior in acquisition of learning and has a lower content in testosterone, were compared. Nimodipine, which is L-type calcium ion channel blocker and has memory-enhancing effects, was administered orally for 5 months. In the cerebral cortex of aged SAMP8, NOS activity was increased compared with that of young-adult SAMP8. Though nimodipine did not alter the contents of NO in any brain regions compared with those in aged SAMP8, nimodipine increased NOS activity in the aged cerebellum. Our data suggest that nimodipine may increase NOS activity through elevation of testosterone level, as testosterone increases NOS only in the cerebellum, although further work is clearly needed to ascertain effects of nimodipine on testosterone metabolism and maintenance in the acquisition of learning.
比较了年轻成年（3个月大）、老年（11个月大）和服用尼莫地平（11个月大）的衰老加速小鼠（SAM）大脑中一氧化氮（NO）水平和NO合酶（NOS）活性，其中SAMP8亚系在学习获得方面较差且睾酮含量较低。尼莫地平是一种L型钙离子通道阻滞剂，具有增强记忆的作用，口服给药5个月。在老年SAMP8的大脑皮质中，与年轻成年SAMP8相比，NOS活性增加。虽然与老年SAMP8相比，尼莫地平在任何脑区均未改变NO的含量，但尼莫地平增加了老年小脑的NOS活性。我们的数据表明，尼莫地平可能通过提高睾酮水平来增加NOS活性，因为睾酮仅在小脑中增加NOS活性，不过显然还需要进一步的研究来确定尼莫地平在学习获得过程中对睾酮代谢和维持的影响。
