Browsing by Author "Cisneros, M."
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Item Acute administration of alcohol modulates pyroglutamyl amino peptidase II activity and mRNA levels in rat limbic regions(2005) De Gortari, P.; Romero, F.; Cisneros, M.; Joseph-Bravo, P.; Department Neurociencias, Instituto Nacional de Psiquiatría, Ramón de la Fuente Muñiz, Calzada México-Xochimilco 101, Col. San Lorenzo Huipulco, C.P. 14370, Mexico.; gortari@imp.edu.mxItem Brain thyrotropin-releasing hormone content varies through amygdaloid kindling development according to afterdischarge frequency and propagation(1998) De Gortari, P.; Joseph-Bravo, P.; Monroy-Ruiz, J.; Martinez, A.; Cisneros, M.; Fernández Guardiola, A.; lnstituto de Biotecnología of Universidad Nacional Autónoma de MéxicoItem Chronic ethanol or glucose consumption alter TRH content and pyroglutamyl aminopeptidase II activity in rat limbic regions(2005) De Gortari, P.; Cisneros, M.; Joseph-Bravo, P.; División de Investigación en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calzada México-Xochimilco 101, Col. San Lorenzo Huipulco, C.P. 14370, México D.F., México.; gortari@imp.edu.mxItem Chronic ingestion of ethanol or glucose solutions affects hypothalamic and limbic TRH metabolism in dams and their pups(2002) De Gortari, P.; Cisneros, M.; Medellín, M.A.; Joseph-Bravo, P.; Depart. of Neuroscience, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calzada México-Xochimilco #101, San Lorenzo Huipulco, Mexico D.F. 14370, Mexico.; gortari@imp.edu.mxItem Differential responses of thyrotropin-releasing hormone (TRH) neurons to cold exposure or suckling indicate functional heterogeneity of the TRH system in the paraventricular nucleus of the rat hypothalamus(S. Karger AG, Basel, 2001) Sánchez, E.; Uribe, R.M.; Corkidi, G.; Zoeller, R.T.; Cisneros, M.; Zacarias, M.; Morales-Chapa, C.; Charli, J.L.; Joseph-Bravo, P.Item Effect of fasting on the content of thyrotropin-releasing hormone and its mRNA in the central nervous system and pyroglutamyl peptidase II activity in the anterior pituitary of post-weaned and adult rats(2000) De Gortari, P.; González-Alzati, M.E.; Cisneros, M.; Joseph-Bravo, P.; Instituto Mexicano Psiquiatría, México City 14370, DF, México.Item TRH inactivation in the extracellular compartment: role of pyroglutamyl peptidase II(1998) Charli, J.L.; Vargas, M.A.; Cisneros, M.; De Gortari, P.; Baeza, M.A.; Jasso, P.; Bourdais, J.; Pérez, L.; Uribe, R.M.; Joseph-Bravo, P.; Departamento de Genética y Fisiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca.TRH (pGlu-His-ProNH2) inactivation in the brain and pituitary extracellular fluid is reviewed. While TRH could be eliminated by alternative mechanisms, i.e. uptake or internalization, modification, hydrolysis by broad specificity peptidases such as pyroglutamyl peptidase I and prolyl endopeptidase, evidence accumulates to support a specific neuroectopeptidase as the main mechanism responsible for its extracellular inactivation. Pyroglutamyl peptidase II (PPII; E.C. 3.4.19.6) is a narrow specificity zinc metallopeptidase hydrolyzing the pyroglutamyl-histidyl peptide bond of TRH. PPII is an integral membrane protein with a small intracellular domain, a transmembrane segment and a large extracellular domain that contains the catalytic site. It is therefore idealy situated to degrade TRH present in the extracellular space. PPII is highly enriched in brain, specifically present in neuronal cells. PPII inhibition enhances recovery of TRH released in vitro. In situ hybridization studies demonstrate that PPII mRNA colocalizes with TRH-receptor mRNA in various brain regions. However, the existence of exceptions suggest that alternative inactivation mechanisms for TRH may operate. PPII activity is regulated in various pharmacological or pathophysiological conditions which alter TRH transmission. It is also present in adenohypophysis, preferentially on lactotrophs, where its activity is stringently regulated by hormones and hypothalamic factors. PPII activity regulation may contribute to adjust TRH neural and hormonal transmissions.