The effect of valproate (VPA) treatment on inositol phosphates (IPs) accumulation in non- stimulated and GnRH-treated female rat anterior pituitary cells in vitro
PBN-AR
Instytucja
Instytut Fizjologii i Żywienia Zwierząt im. Jana Kielanowskiego Polskiej Akademii Nauk
Informacje podstawowe
Główny język publikacji
en
Czasopismo
Neuroendocrinology Letters
ISSN
0172-780X
EISSN
Wydawca
MAGHIRA & MAAS PUBLICATIONS
DOI
URL
Rok publikacji
2013
Numer zeszytu
4
Strony od-do
302-308
Numer tomu
34
Identyfikator DOI
Liczba arkuszy
1.00
Słowa kluczowe
en
VPA
GnRH
PMA
LH
IPs accumulation in rat pituitary cells
Streszczenia
Język
en
Treść
OBJECTIVE: Mechanism(s) responsible for VPA-induced effects on reproductiveaxis activity are not fully recognized. Previously we reported that VPA suppressedonly GnRH-stimulated but not the basal LH release from rat anterior pituitary(AP) cells in vitro. Since the inhibitory effect of VPA was exerted only in GnRHactivatedcells, potential VPA impact on GnRH-R-coupled IP3/PKC signalingcould not be excluded. In this study the effect of VPA on IPs synthesis in nonstimulatedand GnRH-treated rat AP cells was examined. MATERIAL AND METHODS: In the first experiment 5 × 105 cells/ml were incubatedfor 3h with VPA (10 nM–10 μM), PMA (100 nM), GnRH (100 nM), PMA(100 nM) + VPA (10 nM–10 μM), GnRH (100 nM) + VPA (10 nM–10 μM). In thesecond experiment cells were preincubated for 24h with 1μCi myo-[23 H]-inositol,then for 30 min with 10 mM LiCl and finally for 3hr with GnRH (100 nM) VPA(1 μM, 10 μM), GnRH (100 nM) + VPA (1 μM, 10 μM). LH concentration wasmeasured by RIA and intracellular IPs accumulation by ion-exchange chromatographyanalysis. RESULTS: VPA diminished GnRH-stimulated LH release without affectingPMA-induced LH release at any dose tested. Moreover, VPA-induced increase ofIPs accumulation occurred in both non- stimulated and GnRH-treated cells andintensity of cellular response was similar in both groups. CONCLUSION: VPA affects IP3/PKC pathway activity through its up-regulatoryeffect on IPs synthesis in AP cells. VPA-induced inhibition of GnRH-stimulatedLH release from gonadotrope cells appears to be the result of still unrecognizedcellular mechanism.
Cechy publikacji
ORIGINAL_ARTICLE
Inne
System-identifier
626747