Endocrine Abstracts

Somatostatin and dopamine receptors are the major Gi-coupled receptors in somatotrope cells that inhibit hormone secretion from the anterior pituitary. Here, we adapted a novel fluorescence-based screening assay to characterize somatostatin and dopamine receptor signaling in a time-resolved manner. This minimal-invasive technique provides a robust and reliable read out for ligand-induced receptor activation in permanent cell lines and primary pituitary culture. The ...

The human somatostatin receptor 3 (hsst3) is expressed in about 50% of all neuroendocrine tumours. The sst3 receptor is unique among somatostatin receptors which can initiate apoptosis of tumour cells through activation of the tumour suppressor p53. Furthermore, treatment of the sst3 receptor with somatostatin or stable somatostatin analogues such as octreotide or pasireotide can inhibited tumour cell proliferation. However, at present little is known about the agonist-induced...

Introduction: The effect of conventional somatostatin agonists (SA) on somatotroph pituitary adenomas is primarily mediated by somatostatin receptors (sstr) subtype 2. Sstr expression has been proposed as a prognostic marker for response to medical therapy. Earlier studies have shown lower sstr2a expression in SA treated adenomas, but selection bias could not be excluded.Objective: To assess the effect of SA on the immunohistochemical expression of sstr2...

Background: Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis is observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed.Aims: In the present study the expression of the five somatostatin receptor (SSTR) subtypes as well as of the chemokine receptor CXCR4 and of the endothelin receptor A (ETA) was e...

Non-functioning pituitary adenomas (NFPAs), mainly gonadotroph pituitary adenomas (GPAs), are the second most common type of PAs. Given the lack of symptoms secondary to hormone hypersecretion, NFPAs are often diagnosed when they cause mass effects. At this stage they are invasive (50% of cases), they cannot be completely resected and often recur. Despite their frequency, no standard of care drug treatment currently exists for these tumors. SSAs (somatostatin agonists) like oc...