CARRIER-MEDIATED TRANSPORT OF LABELED OXYTOCIN FROM BRAIN TO BLOOD
CARRIER-MEDIATED TRANSPORT OF LABELED OXYTOCIN FROM BRAIN TO BLOOD
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DOI：
10.1159/000125756
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发表时间：
1991-05-01
影响因子：
4.1
通讯作者：
KASTIN, AJ
中科院分区：
文献类型：
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作者：
DURHAM, DA;BANKS, WA;KASTIN, AJ
在小鼠脑室内注射放射性标记的催产素（有或没有未标记的候选抑制剂）后，研究了I-125-催产素从脑到血液的转运。断头后检测到的脑内残留放射性是转运活性的主要决定因素。标记催产素的中枢神经系统的半衰期消失为19.1分钟。抑制10纳摩尔/小鼠的催产素显示了饱和的成分运输。10 nmol剂量的酪氨酸-促黑素细胞激素释放抑制因子（Tyr-MIF-1）和加压素酰胺也显著抑制标记催产素的转运（p < 0.05）。10 nmol剂量的酪氨酸、碘酪氨酸、MIF-1或精氨酸加压素对该系统没有抑制作用。用I-125-催产素与I-131-Tyr-MIF-1同时注射进行的研究，有或没有未标记的催产素或Tyr-MIF-1，与由先前描述的肽转运系统-1（PTS-1）转运的两种肽一致。铝预处理（脑室内注射前60-90分钟给予100 mg/kg元素铝），以前显示抑制PTS-1和其他一些转运系统，抑制标记催产素的转运。脑室内注射I-125-催产素后从血液中收集的放射性在HPLC上洗脱，位置与标记的催产素标准品相同，与酪氨酸、Tyr-MIF-1、MIF-1和托西酰胺不同。得出的结论是，存在一个饱和系统的运输完整的催产素从大脑到血液，这似乎是先前描述的PTS-1。
The transport of I-125-oxytocin from brain to blood was investigated in mice after intraventricular injection of radioactively labeled oxytocin with or without unlabeled candidate inhibitors. Residual radioactivity in the brain detected after decapitation was the principal determinant of transport activity. The half-time disappearance from the central nervous system of labeled oxytocin was 19.1 min. Inhibition by 10 nmol/mouse of oxytocin showed a saturable component to transport. A 10-nmol dose of tyrosine-melanocyte-stimulating hormone release inhibiting factor (Tyr-MIF-1) and pressinamide also significantly inhibited transport of labeled oxytocin (p < 0.05). There was no inhibition of the system by a 10-nmol dose of tyrosine, iodotyrosine, MIF-1, or arginine vasopressin. Studies performed with I-125-oxytocin injected simultaneously with I-131-Tyr-MIF-1 with or without unlabeled oxytocin or Tyr-MIF-1 were consistent with both peptides being transported by the previously described peptide transport system-1 (PTS-1). Pretreatment with aluminum (100 mg/kg of elemental aluminum given 60-90 min before intraventricular injection), previously shown to inhibit PTS-1 and some other transport systems, inhibited the transport of labeled oxytocin. Radioactivity collected from the blood after intraventricular injection of I-125-oxytocin eluted on HPLC at the same position as the labeled oxytocin standard and differently from tyrosine, Tyr-MIF-1, MIF-1 and tocinamide. It is concluded that a saturable system exists for the transport of intact oxytocin from brain to blood which appears to be the previously described PTS-1.