Baumgold J, Zimmerman I, Bambrick L
Brain Res. 1983 Sep;285(3):405-7. doi: 10.1016/0165-3806(83)90040-8.
The binding of [3H]saxitoxin to a crude membrane fraction from rat brains of various ages was determined. We found that at two days before birth, the maximum number of binding sites is 100 fmol/mg of membrane protein. This value increases rapidly for the two weeks following birth, eventually reaching a plateau value of about 800 fmol of toxin sites per mg protein. Since published reports indicate that rat brain myelination occurs primarily between days 15 and 21, we conclude that the development of sodium channels, as measured by [3H]saxitoxin binding, precedes myelination.
测定了[³H]石房蛤毒素与不同年龄大鼠脑粗膜组分的结合情况。我们发现，在出生前两天，结合位点的最大数量为每毫克膜蛋白100飞摩尔。出生后的两周内，该值迅速增加，最终达到每毫克蛋白约800飞摩尔毒素位点的平稳值。由于已发表的报告表明大鼠脑髓鞘形成主要发生在第15天至21天之间，我们得出结论，通过[³H]石房蛤毒素结合测定的钠通道发育先于髓鞘形成。
