218-227The aim of this study was to investigate the
effects of different Luteinizing hormone (LH) and steroid hormones levels on LH
receptor (LHR) expression in the hippocampal cells. Rats (24 males and 24
females) were assigned to four groups: one control and three experimental [gonadectomy
(GDX), gonadectomy + gonadotropin releasing hormone analogue (GDX+GnRHa) and
GDX+GnRHa+estradiol (E2) or testosterone (T)] independently for each gender.
All experimental rats were gonadectomized; then GnRHa was administrated to
GDX+GnRHa group, and GnRHa plus steroid hormone to GDX+GnRHa+E2 or T group in
both genders for four-month. LHR mRNA expression and its protein level in
hippocampal cells were measured using QRT-PCR and Western blotting.
Quantification of mRNA revealed a decrease in LHR transcripts level in
GDX+GnRHa group of females. A significant change was observed between GDX
groups and GDX+GnRHa+E2 or T versus GDX+GnRHa group in females. High levels of
LH decreased significantly the immature isoform of LHR in GDX group compared to
control group in both genders, but low LH concentrations in GDX+GnRHa group
induced immature LHR isoform production only in females. Therefore increased LH
concentration induces production of incomplete LHR transcripts in hippocampal
cells and decreases immature LHR at the protein level. This implies that LH
decreases the efficiency of translation through either producing non-functional
LHR molecules or preventing their translation