113 research outputs found
Uso di inibitori delle Cicloossigenasi di tipo 2 come agenti atti a modificare la farmacoresistenza cellulare
Uso degli inibitori delle cicloossigenasi di tipo 2 per prevenire la comparsa del fenomeno chemioresistenza nelle neoplasie endocrino-relate
Regulation of the neuroendocrine system: C-cell of the thyroid
Descrizione dell'anatomi a fisiologia delle cellule C parafollicolari della tiroid
Anatomy and physiology of the neuroendocrine system. Regulation of the neuroendocrine system: C-cell of the thyroid.
This chapter describes embryonic development, anatomy, calcitonin secretion regulation and function, Calcitonin-related peptide secretion and functio
Pathogenesis and prevalence of hypertension in acromegaly
Hypertension is an important complication of acromegaly, contributing to the increased morbidity and mortality of this condition. Prevalence of hypertension in acromegalic patients is about 35%, ranging from 18 to 60% in different clinical series, and the incidence is higher than in the general population. The lowering of blood pressure observed concomitantly with the reduction in GH levels after successful therapy for acromegaly suggests a relationship between GH and/or IGF-I excess and hypertension. The exact mechanisms underlying the development of hypertension in acromegaly are still not clear but may include several factors depending on the chronic exposure to GH and/or IGF-I excess. Experimental and clinical studies suggest that the anti-natriuretic action of GH (due to direct renal action of GH or IGF-I and/or to indirect, systemic GH or IGF-I-mediated mechanisms) may play a role in the pathogenesis of hypertension. Acromegaly is frequently associated with insulin resistance and hyperinsulinaemia which may induce hypertension by stimulating renal sodium absorption and sympathetic nervous activity. Whether sympathetic tone is altered in acromegalic hypertensive patients remains a matter of debate. Recent studies indicate that an increased sympathetic tone and/or abnormalities in the circadian activity of sympathetic system could play an important role in development and/or maintenance of elevated blood pressure in acromegaly, and may partially account for the increased risk of cardiovascular complications. Acromegalic cardiomiopathy may also concur to elevate blood pressure and can be aggravated by the coexistence of hypertension. Finally, a role of GH and IGF-I as vascular growth factors cannot be excluded. In conclusion, acromegaly is associated with hypertension, but there is still no real consensus in the literature on the mechanisms behind the development of the high blood pressure
Opioid peptides. Analgesic activity of potent dermorphin tetrapeptides. VI.
By employing the mouse tail-flick assay the analgesic activity of selected dermorphin tetrapeptides was assessed. The remarkable differences in potency exhibited by peptides after i.c.v. (500-1000 times higher than morphine) and s.c. (nearly comparable to morphine) administration are probably due to peptidase degradatio
Review of Cortina criteria for the diagnosis of acromegaly
Diagnostic protocols for acromegaly have evolved over time reflecting the refinement of assays for the biochemical assessment of the GH-IGF-I axis and greater understanding of disease process. In February 1999, an International Consensus Conference was held in Cortina, Italy, to define the criteria for cure of acromegaly. This review paper summarizes the diagnostic guidelines proposed in the consensus statement by Giustina et al. In recent years, however, the criteria for both biochemical assessment and long-term monitoring in patients with acromegaly have changed with the development of increasingly sensitive and specific GH assays coupled with the widespread availability of reliable IGF-I assays. For this reason, constant updating of the assessment criteria proposed in the workshop held in Cortina, in 1999, would be advisable
In vitro testing of new somatostatin analogs on pituitary tumor cells
Somatostatin has been discovered as a somatotroph release inhibitory factor (SRIF), and, indeed, it has been demonstrated that SRIF and its analogs can inhibit pituitary tumor hormone secretion and control neoplastic bulk. Several in vitro studies have contributed to the current knowledge of the mechanisms by
which SRIF and its analogs may influence pituitary adenomas, opening the way to new possible therapeutic strategies. This review focuses on the results obtained by testing several SRIF analogs in vitro on pituitary adenomas, concerning both secretory activity and cell viability. These studies provide the basis for further investigations, both at basic and clinical level, of the application of SRIF analogs in the pituitary field
Fisiopatologia dei recettori della somatostatina
L'articolo illustra la fisiopatologia dei recettori della somatostatin
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