Kastin A J, Nissen C, Schally A V, Coy D H
Pharmacol Biochem Behav. 1979 Dec;11(6):717-9. doi: 10.1016/0091-3057(79)90269-7.
It was determined that an antiserum against delta-sleep inducing peptide (DSIP) required eight of the nine constituent amino acids for antigenic activity. Measurement by this radioimmunoassay (RIA) or DSIP-like material in the rat brain, therefore, would necessarily involve almost the entire molecule present in essentially intact form. Injection of 200 microgram DSIP into the carotid artery of rats resulted in a doubling of brain levels of peptide as measured shortly afterwards by RIA. The brain tissue to plasma ratio of radioactivity in rats injected with labeled DSIP was much higher than that in rats injected with labeled inulin; this suggests that the increased amount of material measured by RIA was not merely trapped in the blood vessels. Thus, the results indicate that a small amount of essentially intact peptide can cross the blood-brain barrier. This could represent one of the mechanisms by which central effects of peripherally injected peptides can be exerted.
已确定一种针对δ-睡眠诱导肽（DSIP）的抗血清需要九个组成氨基酸中的八个才能具有抗原活性。因此，通过这种放射免疫测定法（RIA）测量大鼠脑中的DSIP样物质，必然涉及几乎以基本完整形式存在的整个分子。向大鼠颈动脉注射200微克DSIP后，通过RIA不久后测量发现，脑中肽水平翻倍。注射标记DSIP的大鼠脑组织与血浆的放射性比值远高于注射标记菊粉的大鼠；这表明RIA测量到的物质增加量不仅仅被困在血管中。因此，结果表明少量基本完整的肽可以穿过血脑屏障。这可能代表了外周注射肽发挥中枢作用的机制之一。
