A single-centre experience of the implementation of adrenal vein sampling procedure: the impact on the diagnostic work-up in primary aldosteronism.

BACKGROUND: Primary aldosteronism is one of the most common causes of secondary hypertension. Adrenal vein sampling (AVS) remains a "gold standard" procedure in differentiation between unilateral (adenoma) and bilateral (hyperplasia) disease. AIM: The aim of this study was to present our single-centre experience in establishing and implementating the AVS procedure. METHODS: All patients had primary aldosteronism confirmed in a salt-infusion test. AVS was performed sequentially during a continuous intravenous infusion of cosyntropin and was preceded by multislice contrast-enhanced computed tomography (CT) examination of adrenal glands performed a few weeks before AVS in the majority of patients. AVS was regarded as successful if the ratio of each adrenal vein cortisol to inferior vena cava cortisol levels (selectivity index [SI]) was higher than 3.0. In the case of failure, a second attempt was considered in a few weeks. Patients were divided into four groups according to the order of the procedure by quartiles. RESULTS: Between 31 May, 2012 and 5 May, 2016, AVS was performed in 124 patients (69% males, aged 55.3 ± 10.3 years) and was successful in 120 (96.8%) patients. All failed cases were due to the failure of cannulation of the right adrenal vein. The first-attempt success rate was 94.3% (117 of 124 patients) and increased from 83.9% in the first 31 patients to 100% in the last 31 patients. Similarly, the overall success rate increased from 93.5% to 100%. The right SI was significantly higher than the left one (26.4 vs. 11.0, p < 0.0001). Both indices did not differ across quartiles of patients. No complications occurred during the procedure. CONCLUSIONS: The AVS procedure, preceded by adrenal CT, may be implemented into daily diagnostic practice safely with an excellent success rate.

Angiotensins inhibit cell growth in GH3 lactosomatotroph pituitary tumor cell culture: a possible involvement of the p44/42 and p38 MAPK pathways.

The local renin-angiotensin system is present in the pituitary. We investigated the effects of angiotensins on GH3 lactosomatotroph cells proliferation in vitro and the involvement of p44/42 and p38 MAPK inhibitors in the growth-regulatory effects of angiotensins. Materials and Methods. Cell viability using the Mosmann method and proliferation by the measurement of BrdU incorporation during DNA synthesis were estimated. Results. Ang II and ang IV decreased the viability and proliferation of GH3 cells. Inhibitor of p44/42 MAPK attenuated the effects of ang II on cell viability and proliferation but did not affect the ang 5-8-dependent actions. Inhibitor of p38 MAPK prevented the decrease in the number of GH3 cells in ang-II- and ang-IV-treated groups. Conclusions. The growth-inhibitory effect of ang II is possibly mediated by the p44/42 MAPK. The p38 MAPK appears to mediate the inhibitory effects of both ang II and ang 5-8 upon cell survival.

The involvement of angiotensin type 1 and type 2 receptors in estrogen-induced cell proliferation and vascular endothelial growth factor expression in the rat anterior pituitary.

The aim of our study was to examine the involvement of renin-angiotensin system (RAS) in estrogen-induced lactotropes proliferation and vascular endothelial growth factor (VEGF) expression in rat pituitary. The study was performed on Fisher 344 rats underwent 8-day treatment with diethylstilboestrol (DES). The proliferation index (PCNA) and VEGF expression in pituitary sections were estimated using immunohistochemical methods. Treatment with DES increased the number of PCNA-positive cells, VEGF-positive cells, and VEGF-positive blood vessels in pituitary. Stimulatory effect of estrogen on cell proliferation and VEGF expression in blood vessels was attenuated by losartan, PD123319, and captopril. VEGF immunoreactivity in pituitary cells of DES-treated rats was decreased by AT1 antagonist and not changed by AT2 blocker and ACE inhibitor. Our findings suggest the involvement of RAS in DES-induced cell proliferation and VEGF expression in pituitary. Both the AT1 and AT2 receptors appear to mediate the estrogen-dependent mitogenic and proangiogenic effects in rat pituitary.

The effects of angiotensin peptides and angiotensin receptor antagonists on the cell growth and angiogenic activity of GH3 lactosomatotroph cells in vitro.

The local renin-angiotensin system (RAS) is present in the pituitary gland, and inhibitory effects of angiotensins on the lactosomatotroph (GH3) cell growth have been revealed. The aim of this study was to examine the influence of various angiotensin peptides and angiotensin AT1, AT2, and AT4 receptors antagonists on the cell proliferation, viability, and VEGF secretion in pituitary lactosomatotroph GH3 cell culture in order to identify receptors involved in antiproliferative effects of angiotensins on GH3 tumor cells. Cell viability and proliferation using Mosmann method and BrdU incorporation during DNA synthesis, and VEGF secretion using ELISA assay were estimated. The inhibitory effects of ang II, ang IV, and ang 5-8 on the cell viability and BrdU incorporation in GH3 culture were not abolished by AT1, AT2, and AT4 receptors antagonists. Ang II, as well as ang III and ang IV at lower concentrations stimulated the secretion of VEGF in GH3 cell culture. The secretion of VEGF was inhibited by ang III and ang IV at higher concentrations. AT1 and AT2 receptors antagonists prevented the proangiogenic effects of ang II. Ang II, ang IV, and ang 5-8 decrease the cell number and proliferation in GH3 cell culture independently of the AT1, AT2, and AT4 receptors. These peptides affect also secretion of VEGF in culture examined. Both the AT1 and AT2 receptors appear to mediate the proangiogenic effects of ang II.

Angiotensin peptides regulate angiogenic activity in rat anterior pituitary tumour cell cultures.

INTRODUCTION: Angiogenesis has been shown to be necessary for the development and progression of solid tumours. VEGF is one of the crucial pro-angiogenic cytokines produced by the cells of many of the tumours examined, including various types of anterior pituitary adenomas. Angiotensin II (Ang II) is known to regulate the expression of VEGF in a variety of tissues both in the physiological and pathological conditions. Moreover, an association of the renin-angiotensin system (RAS) with oestrogen-induced vascular changes during the development of rat pituitary PRL-secreting adenoma has already been demonstrated. The aim of the study was to determine the in vitro effects of angiotensin peptides (Ang II, Ang III and Ang IV) on the secretion of VEGF in two anterior pituitary adenoma cell cultures: the culture of the rat pituitary lactosomatotrope tumour cell line (GH3) and the primary culture of rat PRL-secreting tumour induced by diethylstilbestrol (DES). MATERIAL AND METHODS: GH3 and prolactinoma cells were cultured in an F10 and an F-12 medium respectively and then placed into 24 multiwell plates (10(5) of GH3 cells/well and 10(6) of rat prolactinoma cells/well). After 12 hours of preincubation the cells underwent 24-hour treatment with Ang II, Ang III or Ang IV at final concentrations of 10(-12), 10(-10), 10(-8) or 10(-6)M and, in the case of the GH3 cells, combined treatment with Ang II (10(-10)M) and specific AT1 or AT2 receptor antagonist (losartan or PD123319 respectively at a concentration of 10(-8) or 10(-7) M). The concentration of VEGF in the supernatant collected was determined using specific ELISA assay kits. Statistical evaluation was performed using Student's test and analysis of variance (ANOVA). Differences were considered significant if p < 0.05. RESULTS: The incubation of both GH3 cells and rat adenoma cells with Ang II, Ang III or Ang IV at concentrations of 10(-12) -10(-8)M resulted in a significant increase in VEGF concentration in the culture medium. Exposure of GH3 cells to Ang III or Ang IV at concentrations of 10(-6)M led to a significant inhibition of cytokine release, and Pearson's correlation curve showed a tendency for Ang II at concentrations of more than 10(-6)M to inhibit VEGF secretion in primary prolactinoma cell culture. The stimulatory influence of Ang II on VEGF secretion in GH3 cell culture was negated by losartan or by PD123319 in both concentrations tested. CONCLUSIONS: Ang II, Ang III and Ang IV affect the secretion of VEGF in cultures of the rat lactosomatotrope GH3 cell line and primary rat prolactinoma cells. Both AT1 and AT2 receptors mediate the stimulatory action of Ang II on the cytokine release in GH3 cell culture. The mechanism of the observed anti-angiogenic effects of angiotensin peptides remains unexplained.

Angiotensins II and IV stimulate the rat anterior pituitary cell proliferation independently of the AT1 receptor subtype.

OBJECTIVES: The purpose of this study was to investigate the effect of angiotensin II (AII) and angiotensin IV (AIV, 3-8 fragment of AII) on the cell proliferation in the anterior pituitary of rat in vivo. MATERIALS AND METHODS: The female adult Wistar rats, ovariectomized 10 days before experiment were injected intraperitoneally with saline, AII, AIV and AII or AIV together with losartan--the specific AT1 receptor subtype antagonist. Bromodeoxyuridine (BrDU) incorporation into anterior pituitary cell nuclei was used as the index of cell proliferation. RESULTS: We observed the increased BrDU-labeling index (LI) in the anterior pituitary of rat treated with either AII or AIV. The proliferogenic effect of neither AII nor AIV was reversed by AT1 specific antagonist losartan. CONCLUSIONS: AII and AIV stimulate the rat anterior pituitary cell proliferation in vivo. This action of both angiotensin peptides is connected with activation of receptor different from AT1 subtype.