Endocrine Abstracts

Fluorescence resonance energy transfer (FRET) using genetically encoded biosensors has proven to be a powerful technique to monitor the spatiotemporal dynamics of cAMP signals stimulated by Gs-coupled receptors in living cells. In contrast, real-time imaging of Gi-mediated cAMP signals under native conditions remains challenging. Here, we describe the use of transgenic mice ubiquitously expressing the highly sensitive cAMP sensor Epac1-camps for cAMP imaging in living pituitar...

For somatostatin, five receptor subtypes (sst1-5) have been identified that are widely distributed in various endocrine tissues and tumors. Potent somatostatin analogs like octreotide, lanreotide and the new multiligand SOM230 – with different binding properties to the receptor subtypes - have been developed. We examined somatostatin receptor protein expression in 134 pituitary tumors of various etiologies. Immunostaining was performed with specific polyclonal anti...

The G protein-coupled (GPCR) somatostatin receptor sst2 transduces the majority of somatostatin actions, including inhibition of hormone and growth factor secretion, cell survival and angiogenesis. Sst2 agonists such as octreotide are widely used for the treatment and diagnostic of human neuroendocrine tumors that frequently over-express sst2. To initiate its inhibitory signalling pathways, sst2 engages, in addition to G protein subunits, different protein partners such as pho...

Introduction: Corticotroph pituitary adenomas that cause Cushing’s disease (CD) predominantly express the dopamine 2 receptor (D2) and somatostatin receptor subtype (sst) 5. The expression of sst2 is relatively low because of downregulating effects of high endogenous cortisol levels. This may explain why the sst2-preferring somatostatin analog octreotide is not effective in CD. To assess whether normalization of urinary free cortisol (UFC) excretion modulates the sst expr...