Somatostatin (sst) acts via a series of 5 G-coupled receptors (sstr1-5) which control exocrine and endocrine secretions and also regulate cellular proliferation and apoptosis in many parts of the body. Recent experimental data suggests that sst plays a roles in ovarian function and the synthetic sstr agonists octreotide has been used in the treatment of polycystic ovarian syndrome. We have investigated the expression of somatostatin receptors (sstr) in human granulosa cells.
Realtime quantitative RT-PCR was used to determine the expression of sstr1-5 by granulosa cells from 11 follicles taken from 6 women undergoing IVF treatment.
Human granulosa cells expressed sstr1 & sstr2 but not sstr3, sstr4 or sstr5. Of the eleven samples, 82% expressed sstr1 and 64% expressed sstr2. Only one granulosa cell sample from one follicle expressed no receptor. The level of expression of sstr 1 and sstr2 was found to be variable and differed between ganulosa cells samples from different follicles from the same patient. No statistical association was found between the levels of receptor expression and patient of origin of the granulosa cells or the presence or absence of an oocyte in the follicle from which the cells were removed.
The presence of sstr1 and sstr2 in granulosa cells suggests an active role for somatostatin in the functioning of the ovary. The presence of sstr2 also provides a mechanism for the reported effects of octreotide on human granulosa cells.
22 - 24 Mar 2004
British Endocrine Societies