【摘要】 我们从人脑中分离得到一个肽,它的结构式为Asn—Ala—Gly—Ala。用合成的肽证明,它和阿片受体有较强的亲和力,有明显的镇痛作用,并和针刺镇痛有关,可能是一个新的神经调制物。更多还原

【Abstract】 A new opioid peptide was isolated from extracts of human brain.From the aminoacid composition and mass spectrometry,the structure of this new peptide has beendetermined as a tetrapeptide with the sequence Asn-Ala-Gly-Ala.It has an affinityfor opiate receptors as determined by the radioreceptor assay.The analgesic effect wasraised markedly after intraventricular injection into the mouse of 100 nmoles of thenew tetrapeptide,lasting for 60 minutes when studied by the hot plate method.When360 nmoles of the peptide in 3 μl of normal saline was applied by microinjection intothe central grey metter of young rabbits,a strong analgesic effect was observed lasti-ng for more than 60 minutes tohen studied by potassium ionophoretic colorimetry.The pain threshold was also raised significantly when 5 μmoles of the peptide wereinjected intravenously into the auris of the rabbit,the effect lasting for 50 minutes.There was no action when 5 μmoles of leu-enkephalin was applied into the rabbits.All these effects could be antagonized by intravenous injection of naloxone.Thistetrapeptide may be a new neuro-modulator in the human brain.更多还原