Effect of Orexin Infusion into Third Ventricle on the Translocator Protein (TSPO) Gene Experession in the Ovary of Pubertal Androgenized Female Rats

In the present study the effects of central injection of Orexin A on the expression of TSPO gene in the ovaries of pubertal androgenized female rats were investigated. 24 neonatal female rats were androgenized on the third day after birth by subcutaneous injection of 50μg TP. Six neonatal female rats in one group were considered as controls. After puberty, the animals in 5 groups (n=6 in each group) received central injections of saline, different doses of Orexin A (2, 4 or 8μg). The ovaries were removed bilaterally and frozen. TSPO gene expression levels was determined by semi quantitative RT-PCR. The mRNA levels of TSPO increased significantly in the ovaries of the androgenized rats compared to controls. Orexin A injections decreased significantly TSPO gene expression compared to the androgenized rats (P <0.05). Androgens may stimulate TSPO gene expression in the ovaries. Orexin A may exert inhibitory effects on reproductive axis partly via reducing the expression of genes involved in the steroidogenesis.