Serum levels of sirtuins, leptin and adiponectin in women with pregnancy-induced hypertension.

INTRODUCTION: Pregnancy-induced hypertension (PIH) and preeclampsia (PE) are associated with disturbed maternal inflammatory response, oxidative stress and vascular endothelial cell dysfunction. Obesity is one of risk factors of PE. Leptin is elevated in obesity and its level correlates positively with the amount of adipose tissue. In contrast, adiponectin levels are decreased in obesity. Sirtuins are expressed in the placenta, however their role in pregnancy-related pathology in humans is not known. AIM OF THE STUDY: The aim of our study was to measure serum concentrations of selected sirtuins, adiponectin and leptin in healthy pregnancy and in women with PIH. MATERIALS AND METHODS: The study included 70 women: 38 healthy pregnant women and 32 women with PIH. Blood samples were obtained between the 20th and 40th week of gestation. Serum levels of sirtuins 1, 3, 6, leptin and adiponectin were measured with ELISA. RESULTS: Leptin levels were significantly higher in PIH group as compared to the controls and correlated positively with BMI. Highest leptin levels were observed in women who needed a cesarean section. Levels of sirtuins 1, 3 and 6 were similar in both groups and did not correlate with BMI. CONCLUSIONS: High leptin levels in PIH women during 3rd trimester might be helpful to predict the necessity for a caesarian section. Blood levels of sirtuins 1, 3 and 6 measured after the 20th week of gestation cannot be regarded as a single diagnostic test for PIH or preeclampsia. More studies to clarify significance of sirtuins in PIH and PE development and diagnosis are needed.

Serum ß-Klotho concentrations are increased in women with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a significant cause of menstrual disorders and infertility in women. The aim of this study was to evaluate the levels of Klotho expression in women with polycystic ovary syndrome. The study involved 67 patients with PCOS, as well as 18 controls. Serum levels of FGF19, FGF21 and ß-Klotho were measured by ELISA technique. The blood samples were obtained between days 2 and 7 of menstrual cycle. The concentrations of ß-Klotho, FGF19 and FGF21 were significantly increased in patients with PCOS; and appear to be statistically significant predictors of PCOS incidence. FGF19 (p = 0.031, OR = 1.01), exact ß-Klotho levels (p = 0.022, OR = 1.01) and ß-Klotho beyond the reference range (p = 0.008, OR = 4.66) were the most strongly correlated with the diagnosis of PCOS. In conclusion, FGF19, FGF21 and ß-Klotho are increased in PCOS, and elevated ß-Klotho concentration may become an useful diagnostic test for this disease. However, additional studies are required to further substantiate this observation.

Blood serum concentrations of gonadotropins and α-subunit in patients with gonadotropinomas in relation to the immunoreactivity of pituitary adenoma.

INTRODUCTION: Although active gonadotropin-secreting pituitary adenomas are considered very rare, the vast majority of pituitary tumours diagnosed as "non-functioning" express gonadotropins or their free ß or α subunits. However, systemic investigations comparing the serum concentrations of follitropin (FSH), lutropin (LH), and α-subunit (αSU) before surgery with the immunoreactivity of the respective substances in the excised tumours are still lacking. MATERIAL AND METHODS: Immunostaining of FSH, LH, and αSU was compared in 43 surgically removed gonadotropin - expressing pitu-itary adenomas with serum concentrations of the above-mentioned substances before surgery in the same patients. RESULTS: The serum concentrations of FSH were elevated (> 11.6 mU/mL) in 8/12 (66.7%) cases of FSH-positive adenomas. By contrast, in FSH-negative tumours the elevation of FSH is absent. Moreover, only 1/25 (4%) patients with LH-positive adenoma had the elevated serum concentration of LH (51.5 mU/mL). The overproduction of LH was not observed in adenomas expressing free ß LH or in LH-negative tumours. In patients with αSU-positive adenomas elevated serum levels of αSU were observed in 3/15 (20%) cases. No αSU elevations were observed in patients with αSU-negative adenomas. The mean serum FSH, LH, and αSU concentrations were higher in patients with FSH, LH, and/or αSU immunopositive tumours in comparison with immunonegative. However, the differences are not statistically significant. CONCLUSIONS: Although "silent" gonadotropinomas constitute a frequent subtype of pituitary adenomas, the "active" subtype (i.e. manifesting by gonadotropin excess) are rare (approx. 4% of all pituitary adenomas). Gonadotropinomas are difficult to diagnose before surgery. The measurement of gonadotropins including αSU is needed but often not sufficient for presurgical diagnosis.

Effects of nitric oxide synthase inhibition on diethylstilbestrol-induced hyperprolactinaemia and pituitary tumourigenesis in rats.

INTRODUCTION: The overexpression of nitric oxide synthase (NOS) has been found in tumours, including pituitary adenomas. It has also been found that NOS is overexpressed in human spontaneous pituitary adenomas. The question arises whether NOS and its product, nitric oxide (NO), are involved in pituitary tumourigenesis. To investigate this question, in the present paper we examine the effects of NOS inhibition on the development of diethylstilbestrol (DES)-induced prolactin-secreting pituitary tumours in rats. MATERIAL AND METHODS: Thirty male Fisher 344 rats, four weeks old, were submitted to subcutaneous implantation of a silastic capsule containing DES (10 mg/capsule) or of an empty capsule. Six weeks after implantation, some of the DES-treated animals received a NOS inhibitor, N-nitro-l-arginine methyl ester (NAME), 1 mg/mL, in their drinking water, for the subsequent 14 days. Eight weeks after the implantation, all the animals were sacrificed, their pituitaries were weighed, and samples of heart blood were collected for prolactin (PRL) and vascular endothelial growth factor (VEGF) measurements. RESULTS: It was found that DES implantation significantly increased pituitary mass, as well as PRL and VEGF concentrations in blood serum. On the other hand, the administration of NAME did not affect significantly either VEGF concentration or pituitary mass. On the other hand, it did induce a further increase in PRL levels. CONCLUSIONS: These findings indicate that NO is involved in oestrogen-induced hyperprolactinaemia, but does not play a crucial role in oestrogen-induced pituitary tumourigenesis.

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.