[Influence of estradiol on pyroglutamyl aminopeptidase activity in the frontal cortex of ovariectomized mice].
BACKGROUND
Pyroglutamyl aminopeptidase (pGluAP) is an omega peptidase widely distributed in fluid and tissues which hydrolyses biological active peptides including thyrotropin releasing hormone (TRH). OBJECTIVES. The aim of present work is to study the influence of estradiol on soluble and membrane bound pGluAP activity in the frontal cortex of female mice.


METHODS
Soluble and membrane bound pGluAP activities in frontal cortex of ovariectomized mice and ovariectomized mice injected with different doses of estradiol were measured using espectrophotometric assays.


RESULTS
Soluble pGluAP activity in frontal cortex did not change after ovariectomy or after the administration of the different doses of estradiol. However, membrane bound pGluAP activity showed a significant increase after ovariectomy. After the administration of the lower dose of estradiol, membrane bond pGluAP activity returned to the same levels detected before the ovariectomy.


CONCLUSIONS
Estradiol modifies membrane bound pGluAP activity which is the principal enzyme involved in the hydrolysis of TRH. Therefore, misregulation of estradiol levels may produce modifications in the neuromodulatory functions of TRH.
García
M J
MJ
Area de Fisiología. Dpto. Ciencias de la Salud; Universidad de Jaén. Jaén, España.
Martínez-Martos
J M
JM
Mayas
M D
MD
Ramírez
M
M
Ramírez-Expósito
M J
MJ
D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects* / Q000201:enzymology*; D006868:Hydrolysis / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D010052:Ovariectomy; D011751:Pyroglutamyl-Peptidase I / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism
D004958:Estradiol; D013973:Thyrotropin-Releasing Hormone; D011751:Pyroglutamyl-Peptidase I