ACTA ENDOCRINOLOGICA (BUC)

The effects of daily evening melatonin (MT) injections on plasma T3 and T4 and pineal thyroxin 5’-deiodinase (5’-D) activity in euthyroid and hypothyroid rats were investigated. Circulating levels of thyroid hormones were monitored and 5’-D activity was measured in pineal homogenates throughout the daily light-dark cycle. In the euthyroid group, T3 and T4 concentrations and pineal 5’-D activity gradually increased during the L-phase of the L/D cycle to reach maximum levels early at night. The lowest values for pineal 5’-D activity and T4 were obtained later at night when endogenous MT production was the highest. MT treatment induced an opposite circadian variation of plasma T3, T4 and pineal 5’-D activity with significant increases later at night and decreases early at night vs. the control group. In the hypothyroid group, the serum T4 and T3 concentrations significantly decreased at all moments assayed. Treatment with MT did not lead to significant changes in the propylthiouracil effect on T4 and T3 levels, but maintained the biphasic response, observed in the MT treated euthyroid group. The increases induced by PTU in pineal 5’-D activity during the light phase, were reduced from 43.61 ? 2.35 ng T3/mg protein / h to 33.36?2.87 ngT3/mg protein/h (p=0.01) by MT injections. In conclusion, the results rendered the presence of the 5’-D in the rat pineal, its activity showing a circadian pattern similar to the circulating T4 levels. The MT treatment induced an opposite circadian variation of serum T3, T4 and pineal 5’-D activity suggesting an interaction between the light/dark cycle, 5’-D activity and responsiveness to MT.

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Background. Following recent years, there is an increased body of literature on the connections that might exist between type 2 diabetes mellitus and the efficiency of bariatric surgery in its reversal compared to other medical approaches such as dieting. Aim. To induce experimentally type 2 diabetes mellitus in rats in order to observe the effects of bariatric surgery in the recovery as well as the reestablishment of normal insulin levels in order to extend the findings in house animals. Materials and methods. This study was conducted in three stages: the first consisted in inducing type 2 diabetes mellitus (T2DM) in 40 young Wistar male rats, by initially feeding them human food high in vegetal fats, oleaginous seeds, simple and complex carbohydrates, sugars, lipids, fats, proteins and fructose for a period of 8 weeks followed by a single low dose of streptozotocin (STZ), administered through intraperitoneal injection. The second stage of the study started when the rats became obese and therefore qualified for the bariatric procedure and the third stage consisted of post-operation supervision and care. The surgical procedure, performed on 10 obese rats, consisted in reducing the size of the stomach by partial gastrectomy of a 1.5 – 2.0 cm wide and 6.5 – 7.5 cm long area on the large curvature. Results. Showed rapid improvements in body weight and blood sugar control after 9 days. Conclusion. After putting the rats on a diet high in carbohydrates, sugars, lipids and fats and administering them STZ, the induction of type 2 diabetes was successful and the partial gastrectomy led to a better blood sugar control. The bariatric procedure provides a faster therapeutic response than conventional diets.

Objective. Adrenal incidentaloma are lesions which are stated incidentally by imaging methods when there is no suspicion of any disease in adrenal gland. Inappropriate Jak2 signaling causes some solid and hematological malignancies. But the Jak2 mutation has not been previously evaluated with regard to adrenal tumors. In this study, we aimed to positivity of the Jak2 mutation in patients with non functioning adrenal incidentaloma (NFAI). Methods. 45 (38 female–7 male) patients, who were followed due to NFAI at Tepecik Training and Research Hospital, Department of Endocrinology and Internal Medicine between February 2014 and March 2015, and 45 (31 female–14 male) healthy controls were included in the study. Results. The average age was 54.02±11.7 years and 38 patients were female, 7 were men. All patients underwent the following analyses for excluding a functioning adrenal mass, overnight dexamethasone suppression test, 24 hour urinary metanephrine and normetanephrine, plasma aldosterone/ renin activity ratio. Jak2 mutation of the patients who were diagnosed as NFAI was all negative. Conclusion. We could not identify the JAK2 gene mutation positivity in any sample. Since other possible mechanisms may throw fresh light on the etiology of adrenal incidentaloma, further clinical studies are needed on this subject.

Context. Angiotensin converting enzyme 2 (ACE2) is highly expressed in the kidney and cleaves angiotensin II to Angiotensin (1–7), annihilating the deleterious effects of angiotensin II which is known to be a strong activator of oxidative stress. Objective. We aimed to evaluate the relationship of oxidative stress to urinary ACE2 (uACE2) in type 2 diabetes mellitus (T2DM) patients. Design. We included consecutive normo or microalbuminuric T2DM patients in an observational transversal study. Routine laboratory investigations, plasma malondialdehyde (MDA, fluorimetric thiobarbituric method) as a marker of prooxidant capacity and superoxide dismutase (SOD, cytochrome reduction method) and catalase (CAT) activity (in erythrocyte lysate by the modification of absorbance method) as two measures of serum antioxidant capacity and uACE2 (ELISA method) were assessed. Results. MDA showed a negative correlation with SOD (r=-0.44, p=0.001), CAT (r=-0.37, p=0.006), uACE2 (r=-0.33, p=0.016) and a positive correlation with glycated haemoglobin (HbA1c) (r=0.49, p<0.001) and associated cardiovascular disease (r=0.42, p=0.001). CAT as also positively correlated to uACE2 (r=0.29, p=0.037). SOD was also negatively correlated with glycemia (r=-0.71, p<0.001) and HbA1c (r=-0.53, p<0.001). Patients with lower MDA (when divided according to median value of 3.88 nmol/ mL) had higher uACE2 57.15(40.3-71.2) pg/mL compared to 38.5(31.8-45.95) pg/mL in patients with higher MDA (p<0.001). In multivariate logistic regression uACE2 was the only predictor for MDA above or below its median (OR=0.94, 95%CI[0.90-0.98], p=0.002). Conclusion. Increased prooxidant serum capacity is associated with lower uACE2 levels in T2DM patients.

Objective. In our study, we aimed to investigate the levels of irisin, nesfatin-1 and the relationship between levels of these relatively new molecules with cardiometabolic risk markers; carotid intima-media thickness (CIMT), epicardial adipose tissue (EAT) thickness in patients with nonfunctional adrenal incidentaloma (NFAI). Materials and Methods. Patients with NFAI (n=59) and age, sex and body mass index-matched healthy control subjects (n=59) were enrolled in this study. Serum glucose, insulin, C-reactive protein (CRP), lipid, irisin and nesfatin-1 levels and echocardiographic CIMT and EAT thickness measurements were performed in patients and controls. Results. The irisin level was 17.58 ± 4.38 pg/mL in the NFAI group, significantly higher (p<0.001) than 14.03 ± 4.03 pg/mL in the control group. Nesfatin-1 level was significantly lower in the NFAI group 194.98 ± 119.15 pg/ mL ((p < 0.001)) versus 303.48 ± 200.78 pg/mL in the control group. A positive correlation was found between irisin and nesfatin-1 levels and CIMT and EAT thickness in the NFAI group. Conclusions. In our study, we found that irisin level was higher and nesfatin-1 level was lower in patients with NFAI, and both irisin and nesfatin-1 levels were associated with CIMT and EAT thickness in NFAI patients.

The aim of this study is to investigate the possible association between hormonal status and adipose tissue characteristics in obese and non-obese subjects. Fourteen obese and 15 nonobese premenopausal female patients were enrolled in the study. Stromal vascular cells were isolated and cultured using modified procedures described by Entenmann and Hauner. In the non-obese group, omental SVCs seeded at a density of 4.12?1.1x103/cm2 in 25-cm2 in culture flasks for measuring cell proliferation and subcutaneus SVCs seeded at a density of 2.05?0.76x103/cm2 in 25-cm2 at culture flasks. In the obese group, omental SVCs seeded at a density of 6.11?1.98x103/cm2 in 25-cm2 at culture flasks for measuring cell proliferation and subcutaneous SVCs seeded at a density of 2.94?0.75x103/cm2 in 25-cm2 in culture flasks. Mean GPDH activity levels were significantly higher in SVCs from the omentum in obese compared to those from the omentum in nonobese (651.9?65.7 vs 405.1?60.1 mU/mg protein). However, GPDH activities were similar in SVCs from the subcutaneous SVCs in obese subjects, compared to those from the subcutaneous SVCs in non-obese subjects (303.5?63.2 vs 367.4?73.7 mU/mg protein). In obese group, omental SVCs number was positively correlated with plasma estradiol (E2) (r=0.604, p=0.017), and fasting insulin levels (r=0.843, p=0.01). It was negatively correlated with plasma progesterone (r=-0.793, p=0.006), prolactin (r=-0.655, p=0.008) and free T3 (FT3) levels(r=-0.630, p=0.01). These findings suggest that there are differences in adipose tissue proliferation capacity and metabolic activity between obese and non-obese subjects. In obese group, the number of omental stromal vascular cells was positively correlated with plasma estradiol and insulin levels.

Introduction: The necessity to determine the levels of pituitary hormones in the cerebrospinal fluid is motivated both by difficulties in the diagnosis of different neuroendocrine disorders, as well as by research purposes such as understanding the transport mechanisms of hormones through the blood brain barrier.\r\nObjective: The aim of this study was to compare the results obtained with different immunometric methods for some pituitary hormones in the serum and CSF in patients with neuroendocrine tumors.\r\nMaterials and methods: The levels of LH, FSH, PRL and TSH were determined simultaneously in the serum and CSF with 3 different immunometric methods using commercial kits: IRMA, FIA and Chemiluminescence for 36 patients. The validation of IRMA method on CSF samples was performed using the dilution test.\r\nResults: The dilution test - as one of validation criteria of an immunoassay - proved that the results obtained in the CSF using the commercially available kits were correct. This enables the use of this sensitive method to accurately demonstrate abnormal levels of pituitary hormones beyond the blood-brain barrier. The correlation between IRMA and FIA: Hormonal concentrations values obtained by IRMA correlate well with those measured by FIA for serum with no significant differences of the mean concentration value for FSH (r=0.93, p: NS) and LH (r=0.99, p: NS), but with a significant difference for PRL (r=0.88, p=0.002). In CSF, mean concentrations values correlate well and we found no differences for TSH (r =0.97, p: NS) and LH (r = 0.94, p: NS), but significant differences for PRL (r= 0.98, p=0.001) and FSH (r=0.98, p=0.001). Statistically significant differences were also found for the CSF/serum ratio for PRL (p=0.08), FSH (p=0.001) and LH (p=0.001). The ratios CSF/serum are significantly higher with IRMA method than with FIA for all the hormones. Except for one patient for all the others we found the ratio CSF/serum less than 1 showing that the pathologic significance of this parameter is not modified due to the type of immunometric assay. A statistically significant difference (p<0.001) was found for mean FSH concentration in CSF with FIA and Chemiluminescent assays .\r\nConclusions: Any immunometric method currently used for the determination of hormones in the serum or plasma has to be validated accordingly in order to be used on CSF. For obtaining results that can be interpreted and compared it is preferred that the same immunometric method is used on both serum and CSF, inside one group of patients. The presence of a control group for the results determined with that method is strongly recommended.

Background. The pineal cytomorphological responsiveness to altered serum T4 levels awaits any comprehensive investigations in mammals .\r\nAim. The aim of the present investigation was to use rats with diversely altered serum T4 level, to study the pineal karyomorphology and functions.\r\nMaterials and Methods. Five groups each with 11 rats were used as controls and T4 (50&#956;g/100g b.w.) for seven consecutive days, thyroidectomized and kept for thirty days and additionally such TX rats, treated with T4 (50&#956;g/100g b.w.) for seven days, were used for pineal karyometry and serum T4 analysis.\r\nResults. They indicated that thyroxine administration evoked hyperactive changes in pineal gland cytomorphology along with enhanced serum T4, as evidenced from increased\r\npinealocyte nuclear diameter (&#956;m) (C 4.71+0.03,T4 5.14+0.04,p<0.001) and decreased nuclear density (C 179.44+4.78,T4 126+4.36,p<0.001) and enhanced serum T4 level\r\n(&#956;g/dL), (C 3.60+0.13,T4 13.40+1.75,p<0.001). Contrarily, thyroidectomized (TX) rats with undetectable T4 levels (<0.05 &#956;g/dL) showed pineal inhibition, as seen from significantly decreased pinealocyte nuclear diameter (&#956;m) (C 4.71+0.03,Tx 4.01+0.04,p<0.001) values, and an increased nuclear density per microscopic field (C179.44+4.78, Tx 208.8+4.47, p<0.005). However, thyroidectomized animals, supplemented with thyroxine (Tx + T4), induced pineal activation as seen from increased pinealocyte nuclear diameter, &#956;m (C 4.71+0.03, Tx + T4 5.26+0.05, p<0.001) associated with increased serum T4 level &#956;g/DL (C 3.60+0.13, Tx+T4 10.92+0.13m p<0.001).\r\nConclusion. The present study argues for a direct pineal-thyroid relationship as interpreted from cytomorphological level and hormone profiles in male albino rats.

Context. Heat Shock Protein 60 (HSP60) is a chaperone protein which is involved in proteins transfer and re-folding of proteins. Objective. Importance of HSP60 in sperm capacitation and facility of sperm-oocyte membrane binding was confirmed, therefore in this study the effect of HSP60 on the rate of in vitro fertilization and the cleavage rate in mouse embryo was investigated. Design. Ten male mice and twenty five female mice were involved to collect sperms and oocytes required for this study. Subjects and Methods. Sperms were collected from the epididymis of male mouse and oocytes were collected from the oviduct of female mouse following ovarian hyperstimulation. Then, capacitated sperms and oocytes were placed together in fertilization medium in four groups in the presence of different concentrations of HSP60 (10, 50 and 100 ng/mL) and in the absence of HSP60. After calculation of the fertilization rate, zygotes were transformed into the other medium for development and the cleavage rate was monitored to blastocyst stage. Results. There was not a significant difference in the rate of fertilization between 10 ng/mL HSP60 group and the control group. The rate of fertilization and two-cell embryo development decreased significantly (P≤0.05) in 100 ng/mL HSP60 compared to other experimental and control groups. Further, the rate of two-cell embryo development increased significantly (P≤0.05) in 10 ng/mL HSP60 compared to other experimental and control groups. Conclusions. The present study demonstrated that HSP60 in low dose had a positive effect on two-cell embryo development, however it did not have any significant effect on the fertilization rate. Conversely, HSP60 had adverse effects on the fertilization and cleavage rates at higher doses.