Objective: 

The sand rat (Psammomys obesus) constitutes a model for studying several metabolic disorders as Mellitus diabetes. In order to perform breeding laboratory conditions, the reproductive function of this diurnal species living in North Occidental Sahara was studied. After histological, cytological and follicular dynamic study, we investigate several regulatory processes in the gonads by immuno histochemistry localization of progesterone, androgen, estrogen and aromatase in the ovaries; FSH and LH in the pituitary gland and the specific receptors of FSH, LH, progesterone and estradiol in the different component of the ovaries.

Methods: 

Ovaries were removed and fixed in 10% formaldehyde or 4% paraformaldehyde or frozen in liquid nitrogen and preserved at -80°C. For immunohistochemistry, we used the LSAB 2 System, Peroxidase DAKO Kit (Biomeda): an indirect method using streptavidin-biotin complex that allows amplification of marking.

Results: 

We identified progesterone, androgen, estrogen and aromatase in the ovaries. Anti 17 b-estradiol antibody presents strong immuno-reactivity in both the oocytes and granulosa cells; theca cells were totally devoid of label. Progesterone label was observed in thecal and granulose cells. FSH and LH were visualized in gonadotropic pituitary cells. FSHR are found only on granulosa cells. LHR were viewed in theca interna, they ensures the production of androgen substrate for aromatase detected only in granulosa, estrogen producing cells. ERa predominate in the theca interna; REb in the granulosa. The RPs were marked in the theca and granulosa. The cell fraction label was specific to estrous phase.

Conclusions: 

Cyclic estrous variations were observed and functional correlations were established.