Pyroglutamyl peptidase II activity is not in the processes of bulbospinal TRHergic neurons.
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.
Joseph-Bravo
P
P
Instituto de Biotecnología, Universidad Nacional Autónoma de México, México.
Fresán
M
M
Cisneros
M
M
Vargas
M A
MA
Charli
J L
JL
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000626:Aminopeptidases / Q000378:metabolism*; D000818:Animals; D002946:Cisterna Magna; D007267:Injections; D008297:Male; D009410:Nerve Degeneration; D009474:Neurons / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism*
D015116:5,7-Dihydroxytryptamine; D013973:Thyrotropin-Releasing Hormone; D000626:Aminopeptidases; C023166:pyroglutamyl-peptidase II; D011761:Pyrrolidonecarboxylic Acid