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Journal Article 2011; 32(6): 805-810 PubMed PMID: 22286791 Citation  Keywords:  Animals, Hypothalamo-Hypophyseal System:physiology, Male, Myocardium:cytology, Oxytocin:metabolism, Pituitary-Adrenal System:physiology, RNA, Messenger:metabolism, Rats, Rats, Inbred Lew, Rats, Sprague-Dawley, Receptors, Oxytocin:genetics,.   

OBJECTIVES: Oxytocin (OT) is a neuropeptide acting both as a peripheral hormone and in the brain as neurotransmitter and neuromodulator. In addition to its well-known effects on milk-ejection and uterine contraction, OT was shown to exert neuroendocrine regulation of heart functions. The aim of this study was to investigate the expression of mRNA of OT receptors (OTR) in rat hearts by real-time quantitative PCR (qPCR). The study was performed in Sprague-Dawley (SD) and Lewis (LE) rat strains, the latter having lower activity of HPA axis.

METHODS: We used adult male SD and LE rats. OTR mRNA expression was detected in all heart chambers by comparing their threshold cycle values (CT) to CT of reference gene β-actin. The relative expression ratios were calculated using the 2-ΔΔCT method. The specificity of reaction of primary antibody with OTRs was tested by Western Blot and localization of OTR in the heart compartments was performed by immunofluorescence with commercial OTR specific antibodies.

RESULTS: We found expression of OTR mRNA in all heart compartments. The expression of OTR mRNA in both atria (LA, RA) was much higher than in the ventricles (RV, LV). By using two-way ANOVA we found no statistical differences between corresponding compartments of SD and LE rats. Immunohistochemical studies showed that OTR staining is not related to neuronal tissue and findings from left atrium indicate that prevalent localization of OTR is on cell membranes of cardiomyocytes.

CONCLUSIONS: The finding of expression of OTR mRNA by real-time qPCR and proof of OTR staining by immunohistochemistry in all heart compartments indicate that OT and its receptors may have function as a cardiovascular hormone. The differences in the HPA axis activity, as is exemplified in Sprague-Dawley and Lewis rat strain, do not project in the expression of OTR mRNA under basal condition. The effect of activity of HPA on OTR expression should be studied under stimulated conditions as it was performed in the behavioral studies....

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Journal Article 2011; 32(6): 769-773 PubMed PMID: 22286790 Citation  Keywords:  Animals, Cells, Cultured, Estradiol:pharmacology, Female, Follicle Stimulating Hormone:secretion, Intracellular Signaling Peptides and Proteins:metabolism, Luteinizing Hormone:secretion, Neuropeptides:metabolism, Orexins, Ovariectomy, Pituitary Gland:cyto.   

OBJECTIVES: Orexin A (OxA) is a regulatory neuropeptide which is involved in the control of various autonomic and neuroendocrine functions. It regulates sleep-wake cycle, food intake and modulates the hypothalamic and pituitary hormones secretion. Orexin A acts through two types of receptors, which proved to exist in the pituitary. This may indicate the possibility of direct action of OxA on the adenohypophysis level. The aim of this study was to evaluate the direct effect of orexin A on gonadotropin (LH and FSH) release from cultured pituitary cells of immature female rats as well as mature female rats (ovariectomized and ovariectomized and estradiol treated rats).

MATERIAL AND METHODS: The effect of 0.1 nM and 100 nM orexin A on LH and FSH release from anterior pituitary cells after 1 h of incubation was examined in immature female rats (IM) as well as mature female (ovariectomized - M/OVX; and ovariectomized and estradiol treated - M/OVX+E2) rats. The concentration of LH and FSH in medium was determined by RIA method.

RESULTS: Orexin A at a dose of 0.1 nM and 100 nM significantly stimulated LH secretion in IM group. In M/OVX group release of LH was inhibited by OxA only in higher dose (100 nM). No effect of orexin A on FSH secretion was found.

CONCLUSIONS: OxA may directly modulate LH secretion from cultured pituitary cells and it has the contradictory effect on LH release in immature and ovariectomized mature female rats....

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Journal Article 2011; 32(6): 811-815 PubMed PMID: 22286789 Citation  Keywords:  Animals, Behavior, Animal:physiology, Estradiol:pharmacology, Estrogens:pharmacology, Facial Pain:physiopathology, Female, Male, Ovariectomy, Pain Measurement, Pain Threshold:drug effects, RNA, Messenger:metabolism, Random Allocation, Rats, Rats, Sprague-.   

OBJECTIVES: P2X3 receptors are expressed in trigeminal ganglia (TG) and participate in the transduction of facial pain. However, the mechanisms underlying P2X receptor-mediated nociception at different estrogen levels has not been examined.

METHODS: In this study, female rats were randomly divided into sham-operated (sham), ovariectomized (OVX), and estrogen-treated groups. In each group, the facial mechanical pain threshold was tested and the TG were harvested for a real-time PCR analysis of P2X3 receptor mRNA and western blot analysis of protein level.

RESULTS: In OVX rats we found that the mechanical pain threshold was significantly decreased compared with that in sham rats. Estrogen replacement reversed the decrease. The expression of P2X3 mRNA level in TG from OVX rats was significantly increased, consistent with the enhanced P2X3 receptor in protein level. Estrogen replacement could decrease the expression of P2X3 receptor in both mRNA and protein level.

CONCLUSION: These results indicate that estrogen might modulate the transduction of facial pain by inhibiting P2X3 receptor in TG....

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Journal Article 2011; 32(6): 836-840 PubMed PMID: 22286788 Citation  Keywords:  Adolescent, Female, Humans, Impulsive Behavior:metabolism, Loneliness, Neuropsychological Tests, Saliva:chemistry, Testosterone:metabolism,.   

OBJECTIVE: Adolescence is characterized by increases in loneliness, impulsiveness and circulating testosterone levels. We investigated the relationship between these characteristics in adolescent females.

METHODS: For this purpose, we measured impulsivity and loneliness by means of a Go/No-go task and the UCLA loneliness scale, respectively. Testosterone levels in saliva were measured by Enzyme-Linked Immunosorbent Assay (ELISA).

RESULTS: The results showed that testosterone and loneliness have a positive relevance to impulsivity in adolescent females, whereas there was no relationship between loneliness and testosterone levels.

CONCLUSIONS: These results suggest that testosterone and loneliness modulate impulsivity via distinctive pathways....

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Journal Article 2011; 32(6): 763-768 PubMed PMID: 22286787 Citation  Keywords:  Animals, Dehydration:physiopathology, Glucose Transport Proteins, Facilitative:metabolism, Glutamic Acid:metabolism, Male, Paraventricular Hypothalamic Nucleus:metabolism, Rats, Rats, Sprague-Dawley, Sodium:metabolism, Synaptosomes:metabolism, Water Depri.   

OBJECTIVES: The purpose of this study was to identify and characterize Na+-dependent, high affinity glutamate transporter (GLUT) activity in the hypothalamic paraventricular nucleus (PVN) and to compare GLUT activity in PVN of euhydrated versus water-deprived rats.

METHODS: Sprague-Dawley rats were deprived of water for two days before sacrifice. Control rats received water ad libitum. After sacrifice, PVN and cerebrum were removed and synaptosomes were prepared using standard techniques. Glutamate uptake was measured using [3H]-glutamate as substrate, physiological buffer, approximately 100 µg of synaptosomal tissue per assay and a Brandel cell harvester.

RESULTS: Glutamate uptake was saturable in PVN synaptosomes from euhydrated, control rats with a Vmax of 541 ± 22 pmol/min-mg protein (SEM) and Km of 17.6 ± 3.8 µM (SEM). In contrast, Vmax of glutamate uptake was 808 ± 58 pmol/min-mg protein in PVN of rats deprived of water for 2 days. This was significantly higher than controls (p<0.001). Km was 21.2 ± 7.3 µM and not significantly different from controls (NS).

CONCLUSIONS: Our results suggest that water deprivation of rats results in significantly higher synaptosomal glutamate uptake in PVN. Although the exact mechanism is unknown, increased transcription of the GLUT gene and/or increased cell surface expression of GLUT may contribute to the observed increase of glutamate uptake in dehydrated rats. Increased glutamate uptake may serve to restrict dehydration-induced activation of PVN efferent pathways specifically involved in release of neurohypophysial hormones and activation of sympathetic outflow that operate to maintain body fluid balance and cardiovascular function....

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Journal Article 2011; 32(6): 790-798 PubMed PMID: 22286786 Citation  Keywords:  Anxiety Disorders:metabolism, Attention Deficit Disorder with Hyperactivity:metabolism, Child, Circadian Rhythm:physiology, Humans, Melatonin:metabolism, Saliva:chemistry,.   

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) and anxiety disorders are the most frequent psychiatric disorders in children. Changes in rhythms of symptoms during the day may be influenced by genetic, biological and psychological factors. Some changes of melatonin rhythm may hypothetically change the activity of ADHD by changing arousal or in anxiety children by changing their emotional state. In our present study we identify one group of ADHD children combine type without comorbids, one group of anxiety children and a control group. Most changes of melatonin daily rhythm are supposed in the anxiety group, especially in sleeping time, and more prominent change in the ADHD group with prominent hyperactivity and conduct disorder symptoms.

METHODS: Thirty-four ADHD and forty-three control children and eleven anxiety children, all 6-12 years old, participated in the study. The saliva specimens were collected in four different sessions during the school year, around the time of the spring and autumn equinox, when the natural light lasted 11.2 h ± 0.9 h.

RESULTS AND CONCLUSIONS: In our study more symptoms of conduct disorder elevated positive or negative correlations between psychopathology and saliva level of melatonin in ADHD and anxiety samples. We hypothesize that co-morbidity of ADHD or anxiety with impulsivity and conduct disorders might have elevated correlations between psychopathology of ADHD or anxiety and plasma melatonin level....

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Journal Article 2011; 32(6): 857-864 PubMed PMID: 22286784 Citation  Keywords:  Adult, Body Mass Index, Estradiol:blood, Female, Human Growth Hormone:blood, Humans, Insulin-Like Growth Factor Binding Protein 3:blood, Insulin-Like Growth Factor I:metabolism, Young Adult,.   

OBJECTIVE: To compare the influence of low and normal endogenous estradiol concentration on circulating hGH, IGF-I and IGFBP-3 levels as well as on mutual correlations of these parameters.

PATIENTS: 45 women (age 30.7 ± 9.0 years, BMI 25.7 ± 8.0) divided into group A - 15 hypoestrogenic women and group B - 30 normoestrogenic controls. Neither of the women was menopausal nor hyperprolactinemic.

METHODS: Blood sample was taken at the standard conditions prior to the initiation of hormonal supplementation therapy in group A and at the day 3-5 of menstrual cycle in group B. Serum hGH, IGF-I, IGFBP-3, insulin, testosterone, sex hormone binding globulin (SHBG) dihydroepiandrosterone sulphate (DHEAS) and LH as well as prolactin (PRL), FSH and estradiol levels were measured by standard RIA kits.

RESULTS: Mean IGF-1, LH, FSH, testosterone and estradiol and PRL plasma levels were lower in group A compared to group B. There were no significant differences in mean SHBG, insulin and DHEAS levels. There were also no differences in mean: age, body mass, BMI as well as percentage of each BMI range between groups. Regardless the estradiol level the IGF-I/age link was found in both groups. A IGF-I/IGFBP-3 relation was found in both groups. IGF-I/estradiol link was seen only in group A. In group B hGH/SHBG link was found, in group A this relation was indirect. A link between hGH and testosterone levels was found only in group B. SHBG was related in group B to IGFBP-3, testosterone and to DHEAS. Insulin/IGFBP-3 link was seen in group B. The stepwise multiple regression revealed DHEAS and LH as predictors of IGF-I level in group A, while in group B none of the parameters predicted IGF-I level. The results of the same analysis in case of hGH are as follows: in group A hGH level was predicted by estradiol and SHBG. In group B none of factors predicted hGH levels.

CONCLUSION: Estradiol plasma level is correlated to circulating IGF-I, albeit the relation seems to be biphasic....

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Comparative Study 2011; 32(6): 865-873 PubMed PMID: 22286783 Citation  Keywords:  ACTH Syndrome, Ectopic:diagnosis, Adenoma:diagnosis, Adolescent, Adult, Cushing Syndrome:diagnosis, Female, Humans, Male, Middle Aged, Petrosal Sinus Sampling:methods, Retrospective Studies, Treatment Outcome, Young Adult,.   

BACKGROUND: Bilateral inferior petrosal sinus sampling (BIPSS), currently, is the gold standard test for the differential diagnosis of Cushing's syndrome (CS), but few data are available on the efficacy and accuracy of BIPSS in the qualitative diagnosis of ACTH-dependent CS and lateralization of Cushing's disease (CD); especially, the evaluation of BIPSS in all CD patients with transsphenoidal surgery (TSS). As a result, we investigated whether such invasive test compared other noninvasive tests may affect the efficacy and accuracy of diagnosis and TSS treatment in ACTH-dependent CS.

OBJECTIVE: We investigated the efficacy and lateralized accuracy of diagnostic and therapeutic of BIPSS in ACTH-dependent CS.

SETTINGS: A retrospective analysis was conducted at a single care center in Ruijin Hospital, Shanghai City.

PARTICIPANTS: CD was confirmed by histopathology in one hundred and nineteen patients, include sixty-four patients with BIPSS procedure; and ectopic ACTH syndrome (EAS) also was histological confirmed in five patients. MAIN INTERVENTIONS AND OUTCOMES: Sixty-nine patients were all administrated with BIPSS test. Additionally, other noninvasive tests included endocrine examinations, low and high dose dexamethasone suppression test (LDDST and HDDST); imagine examinations include magnetic resonance imaging (MRI) and positron emission tomography and computerized tomography (PET-CT).Gradients of inferior petrosal sinus (IPS) to peripheral (IPS/P) ACTH were calculated before and after BIPSS procedure completed five minutes.

RESULTS: In patients with proven pituitary cases, stringent response criteria in MRI and HDDST testing were fully by 51.6% and 60.3% respectively. While BIPSS, gave direct evidence of CD in 90.6% of these cases. The sensitivity for a basal IPS/P gradient greater than 2 was 89.1%, with 100% specificity and a diagnostic accuracy of 87.5%. A subgroup of 14 patients (all were CD) had contradictory responses to routine test with HDDST; while the sensitivity, specificity and accuracy of BIPSS were 100% respectively. Compared with the MRI and DST, we accepted Receiver Operating Characteristic (ROC) curve analysis showed that BIPSS performance is the best efficacy diagnosis tool in CS. In total, 57 of 64 patients with CD had an IPS/P gradient greater than 2, resulting in the sensitivity, specificity and diagnostic accuracy are 90.5%, 100%, 95.2% respectively. Additionally, the accuracy value of BIPSS in indicating dominant side should also be stressed in adenoma lateralization of CD. Finally, BIPSS test contributed most in the remission efficacy of TSS; then remission rate of underwent BIPSS group is 92.2% compared to the rate of 80% in without BIPSS group (p<0.01), Compared with other noninvasive tests, turn out the highest accuracy rate in remission.

CONCLUSIONS: The application of BIPSS is associated with efficacy and accuracy of ACTH-dependent CS and lateralization of CD, what's more, all above, we can conclude that BIPSS is associated with the surgical therapy in CD patients. Therefore, BIPSS dedicate to the diagnosis, treatment and intraoperation administration of ACTH-dependent CS....

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