[Dietary cholesterol modifies pyroglutamyl aminopeptidase activity in mouse frontal cortex. Sexual differences].
BACKGROUND
Pyroglutamyl aminopeptidase (pGluAP) is an omega peptidase widely distributed in fluid and tissues, which hydrolyses biological active peptides including thyrotropin-releasing-hormone (TRH). In the last years, different endocrine and extraendocrine functions have been attributed to TRH.


OBJECTIVE
The aim of present work is to study the influence of high dietary cholesterol on soluble and membrane bound pGluAP activity in frontal cortex of male and female mice. Material and methods. Soluble and membrane bound pGluAP activities of frontal cortex of mice feeding during 15 days, a standard diet enriched with cholesterol (1%) and cholic acid (0.5%) were measured using fluorimetric assays.


RESULTS
Significant increases were observed in membrane bound pGluAP activity in males and females. No changes were detected in soluble pGluAP activity in frontal cortex of females but a significant increase was observed in this enzymatic activity in males.


CONCLUSIONS
High dietary cholesterol induces a significant increase in tissue pGluAP activity. These increases may produce changes in TRH metabolism which may be related with alterations in its neuromodulatory functions and with the possible relationship between TRH and other neurotransmitter systems.
Ramírez Expósito
M J
MJ
Area de Fisiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales y de la Salud, Universidad de Jaén, Jaén, España.
García
M J
MJ
Mayas
M D
MD
Ramírez
M
M
Martínez Martos
J M
JM
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D005260:Female; D005470:Fluorometry; D005625:Frontal Lobe / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011751:Pyroglutamyl-Peptidase I / Q000378:metabolism*; D012737:Sex Factors; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism
D002791:Cholesterol, Dietary; D013973:Thyrotropin-Releasing Hormone; D011751:Pyroglutamyl-Peptidase I