Joseph-Bravo P, Fresán M, Cisneros M, Vargas M A, Charli J L
Instituto de Biotecnología, Universidad Nacional Autónoma de México, México.
Neurosci Lett. 1994 Sep 12;178(2):243-6. doi: 10.1016/0304-3940(94)90769-2.
Pyroglutamyl peptidase II (PPII) is a neuronal ectoenzyme involved in released thyrotropin-releasing hormone (TRH) inactivation. In an attempt to define if it is present in the pre or postsynaptic membrane, we induced neuronal degeneration of serotonin-TRHergic cells that project from raphe nuclei to the spinal cord. 2-4 weeks after intracisternal injection of 5,7-dihydroxytryptamine, TRH levels decreased over 70% in the cervical, thoracic or lumbar regions of spinal cord. In contrast, no change of PPII activity was observed. Longer times after injection (6-8 weeks), a 59-66% increase in activity was detected in the lumbar region. These data suggest that PPII is not localized in these TRHergic neurons but probably in the target cells.
焦谷氨酸肽酶II（PPII）是一种神经元外切酶，参与释放的促甲状腺激素释放激素（TRH）的失活。为了确定它是存在于突触前膜还是突触后膜，我们诱导了从缝核投射到脊髓的5-羟色胺-TRH能细胞的神经元变性。脑池内注射5,7-二羟基色胺2-4周后，脊髓颈段、胸段或腰段的TRH水平下降了70%以上。相比之下，未观察到PPII活性的变化。注射后较长时间（6-8周），在腰段检测到活性增加了59%-66%。这些数据表明，PPII并不定位于这些TRH能神经元，而可能定位于靶细胞。
