Endocrine Abstracts

Background Somatostatin has various biological effects such as modulation of exocrine and endocrine secretions, proliferation and apoptosis. These effects have been shown to be mediated via G-protein linked receptors known as somatostatin receptors 1-5 (SST 1-5). It has been shown that SST 2 in particular can be modulated by estrogen. The phytoestrogen genistein acts through the estrogen receptor beta and has been shown to have opposing effects on cell proliferation at different doses, pro- proliferation at low doses and anti-proliferation at high doses. It is unknown whether sst expression may be altered by genistein and therefore we examined the expression of sst in human umbilical vein endothelial cells, before and after genistein treatment. Methods Newly extracted human umbilical vein endothelial cells were exposed to 0.1micromolar per litre genistein for a set of time period ranging from 20 minutes to 24 hours before total mRNA was extracted. SST mRNA was then identified using quantitative reverse transcriptase PCR. Results SST 1, 2, 3 and 5 were consistently expressed in the cells examined. A short-term modulation of receptor 1, 2 and 5 expression was observed with 20 minutes of genistein exposure. SST 1 was downregulated while SST 2 and 5 were upregulated by 2-4 folds. Furthermore, SST 5 was upregulated by genistein throughout the 24 hours treatment. Conclusion SST 1, 2 and 5 are altered by the phytoestrogen genistein.