Endocrine Abstracts

Introduction: The effects of dopamine (DA), serotonin (5-HT), histamine (HA) adrenaline (ADR), noradrenaline (NADR) and K+ administration on vasopressin (VP) secretion were studied in 13–14 days cultures of rat neurohypophyseal (NH) cells, and it was examined whether orexin (ORX) can modify the VP release enhancement induced by these monoaminergic compounds.Methods: An enzymatic dissociation technique was used to prepare the rat NH cell c...

Neuroendocrine tumors (NETs) of GI tract are a heterogeneous group of neoplasms that secrete peptides and amines. Small bowel NETs originate from enterochromaffin (EC) cells and secrete chromogranin A (CgA) and serotonin (5-HT). NETs are highly vascular, a reflection of increased tumour related angiogenesis. Adenosine, the major regulator of angiogenesis, is released by enhanced degradation of ATP, during cellular stress, damage and hypoxia.Aims: Aims of...

Cancer cells have shown an overexpressed fructose transporter GLUT5 and preferential utilization of fructose as compared to glucose, implicating that a fructose-based analogue would be a useful target for diagnosis and treatment of cancer. We have successfully synthesized the fructose conjugated-gefitinib compounds {N-[4-(3-chloro-4-(3-fluorobenzyloxy)phenylamino)-7-methoxy-quinazolin-6-yl]-4- [N-methyl-N-(1-deoxy-1-fructosyl)]aminobutanamide}, and examined its antitumor effic...

Introduction: Elevated intraocular (vitreous) leptin is implicated in proliferative diabetic retinopathy. The source of vitreous leptin is uncertain and it could be derived from systemic leptin. However we showed that leptin (ob) mRNA is present in rat retina, suggesting that retinal tissue could also be a source of intraocular leptin. The present investigation quantified ob mRNA in human retinal tissue obtained from diabetic and control cadavers. In a parall...

Aim: The most common clinical presentation of primary hyperparathyroidism (PHPT) is asymptomatıc and it is diagnosed incidentally without developing complications.In our study, we aimed to examine the characteristics of participants with primary hyperparathyroidism and the relationship between bone mineral density (BMD) and hypercalciuria.Methods: Consecutive 191 normocalciuric (24-h urinary calcium<400 mg/day) patients with PHPT (51±13 yea...

In the pituitary, estrogens regulate several cell functions via the activation of membrane-associated estrogen receptors (mERs). We have previously reported that both 17β-estradiol (E2) and membrane-impermeable E2-BSA induce rapid apoptotic actions in anterior pituitary (AP) cells, lactotropes and somatotropes through the activation of mERs.In the present study, we investigated the involvement of mERα in the apoptotic action of E2 in...

Introduction: Cushing’s syndrome (CS) is a rare disease characterized by clinical features that show overlap with the ‘metabolic syndrome’. Pilot studies regarding the use facial image analysis software as a novel diagnostic tool in acromegaly and CS have shown promising results. Distinguishing CS patients from patients that show similar features without true hypercortisolism remains a challenge in clinical practice. To address this particular problem, we evalua...

TSH is the main regulator of the thyroid hormones (THs) synthesis/secretion, which in turn exert a negative feedback mechanism on the Tshb mRNA expression in the pituitary gland by reducing their transcription rate. Some of triiodothyronine (T3) effects are also shown in short period of time, characterizing the non genomic actions of THs. It has been shown previously that T3 acts on posttranscriptional steps of TSH synthesis and reduces its secre...

Adaptor protein-2 (AP2) is a heterotetramer of α, β, μ, and σ subunits that is pivotal in clathrin-mediated endocytosis and facilitates internalisation of plasma membrane constituents such as the calcium-sensing receptor (CaSR). AP2 σ subunit (AP2σ) missense mutations (Arg15Cys, Arg15His and Arg15Leu) result in familial hypocalciuric hypercalcaemia type 3 (FHH3) and decrease the sensitivity of CaSR-expressing cells to changes in extracellular calc...

Introduction: Cytokines have been suggested to be involved in modulating anti-tumor responses and promoting tumor growth. Some studies have indicated that cytokines could also be involved in the pathogenesis of pituitary tumors. Th17 cells, characterized by expression of several cytokines as interleukin 22 (IL 22), might have a role in tumor immune-surveillance. IL-22 is a cytokine involved in the modulation of tissue responses during inflammation and, through activation of St...