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Journal Article 2006; 27(6): 755-757 PubMed PMID: 17187020 Citation  Keywords:  Adult, Ghrelin, Humans, Injections, Intravenous, Male, Neuropeptide Y:blood, Peptide Hormones:administration & dosage, Reference Values, Stimulation, Chemical,.   

OBJECTIVE: Ghrelin is a 28 amino-acid peptide with a strong GH-releasing activity and a complex role in regulation of appetite, fuel utilization, body weight and composition. Neuropeptide Y (NPY) is a well-known stimulator of pathways favouring food intake and energy storage. Recently, studies in rodents suggested a possible mediation of ghrelin action by NPY. In contrast, until now no evidence of ghrelin-NPY interaction in humans has been provided. In the present study, we examined whether ghrelin influences NPY secretion in normal men.

SUBJECTS AND DESIGN: Twelve healthy normal men (aged 24-35 years; body mass index (BMI) 22.3+/-0.93 kg/m2) were tested twice at 08.00 AM on two different days, in random order at weekly intervals, after an overnight fast and rest in bed. An intravenous bolus of 1 microg/kg body weight ghrelin (esperimental test) or an equal amount of normal saline (control test) was injected at time 0. Blood was taken before and over 90 minutes after injections, and was used for the measurement of plasma NPY levels.

RESULTS: Plasma levels of NPY slightly, but significantly rose in response to ghrelin, with a mean peak level at 15 min after injection, whereas no significant change was observed after saline administration.

MAIN FINDING: Our results show a significant enhancement of plasma NPY levels under ghrelin stimulation.

CONCLUSIONS: To our knowledge, this is the first demonstration of a ghrelin-NPY interaction in humans, which may suggest a possible mediation of ghrelin action by NPY in humans....

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Journal Article 2006; 27(6): 795-798 PubMed PMID: 17187004 Citation  Keywords:  Adult, Female, Glycoprotein Hormones, alpha Subunit:metabolism, Humans, Male, Middle Aged, Prolactin:metabolism, Reference Values, Stimulation, Chemical, Thyroid Function Tests, Thyrotropin:metabolism, Thyrotropin-Releasing Hormone:physiology,.   

OBJECTIVE: The alpha-subunit (Alpha-SU) response to TRH was studied to examine the response of alpha-SU under TRH stimulation in normal situation.

METHODS: Thirty seven healthy individuals were included in the study. They were divided into two groups according to the data taken: A with TSH equal or more than seven fold the basal values (0: 3.14+/-1.2 microU/ml., 30 after TRH: 20.22+/-4.6 microU/ml) and B with TSH 2 to 6 fold the basal values (0: 0.5+/-0.1 microU/ml., 30 after TRH: 2.9+/-0.5 microU/ml). Both groups exhibited similar FT3 and FT4 levels.

RESULTS: In group A, prolactin displayed a 3 fold increase from the basal values, whereas alpha-SU increased 4 fold with a difference being statistically significant (p<0.001). In contrast, in group B individuals neither prolactin nor alpha-SU exhibited any significant difference from the basal values.

CONCLUSION: The expression of alpha-SU upon TRH stimulation is dependent on the TSH basal values....

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Journal Article 2006; 27(6): 719-723 PubMed PMID: 17187003 Citation  Keywords:  Case-Control Studies, Docosahexaenoic Acids:blood, Fatty Acids, Omega-3:blood, Fatty Acids, Unsaturated:blood, Humans, Male, Pedophilia:blood, Reference Values, Serotonin:metabolism, Statistics, Nonparametric,.   

BACKGROUND: Previous studies have suggested that abnormalities in plasma phospholipid fatty acids may play a role in aggressive behavior. Recently, it was suggested that a dysfunctional serotonergic turnover in the brain may be involved in the etiopathology of pedophilia. Depletion of n-3 polyunsaturated fatty acids (PUFA) may cause alterations in the serotonergic system that may be related to pedophilia and aggression.

METHODS: This study examines the serum phospholipid n-3 and n-6 PUFA fractions in pedophilia. Twenty-seven pedophilic men and eighteen healthy volunteers participated in this study.

RESULTS: In pedophilia there was a significant depletion of the C22:6n-3 (docosahexaenoic acid, DHA), total n-3 fractions and an increase in the total n-6/n-3 and C20:4n-6/C20:5n-3 (arachidonic acid/eicosapentaenoic acid) ratios. Using the NEO Personality Inventory, lower DHA in pedophiles is related to more impulsiveness and lower agreeableness (trust, altruism, straightforwardness, compliance) and conscientiousness (self-discipline).

CONCLUSIONS: The results of this study suggest that a depletion of the serum phospholipid n-3 higher unsaturated fatty acids (HUFAs) and, in particular, of DHA may take part in the pathophysiology of pedophilia. One hypothesis is that a depletion of n-3 HUFAs and DHA may cause alterations in the serotonergic turnover, which are related to impulse discontrol and aggression-hostility, behaviors which are associated with pedophilia....

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Clinical Trial 2006; 27(6): 822-827 PubMed PMID: 16892007 Citation  Keywords:  Adult, Copper:blood, Exercise:physiology, Humans, Male, Oxygen Consumption:physiology, Reference Values, Running:physiology, Zinc:blood,.   

: This study was carried out to investigate the effects of 6-week aerobic exercise program upon blood Zn and Cu levels. There were 12 male university students with an average age of 21.67+/-0.89 years and no regular training habits participated in the study. The participants were subjected three days a week 1 hour a day continuous running program on treadmill with an intensity of 60-70% for a period of six weeks. They were fed with zinc and copper free diet throughout the study and it was made sure that they were not using copper or zinc containing vitamin tablets. The difference between the pre and post study period were found to be statistically significant as regards to both resting and maximal loading conditions (p<0.01). The pre and post training maxVO2 values were also found to be positively correlated with the copper and zinc levels in blood. Both the copper and zinc blood levels were found decreased after the training period p<0.05....

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Clinical Trial 2006; 27(3): 307-313 PubMed PMID: 16816836 Citation  Keywords:  Antidepressive Agents, Second-Generation:blood, Antidepressive Agents, Tricyclic:blood, Erythrocyte Membrane:drug effects, Female, Humans, Male, Neurotransmitter Uptake Inhibitors:blood, Plasma:metabolism, Reference Values, Structure-Activity Relationship.   

OBJECTIVE: The distribution of different antidepressants between plasma and red blood cells (RBCs) or between water and erythrocyte membranes (ghosts) has not been sufficiently compared so far.

MATERIALS AND METHODS: Distribution of seven antidepressants (amitriptyline, nortriptyline, imipramine, desipramine, didesmethylimipramine, dothiepin, and citalopram) was measured in vitro in small volumes of blood or erythrocyte membrane suspension using radiolabeled drugs. Blood samples were taken from healthy subjects.

RESULTS: The distribution of antidepressants between plasma and RBCs is strongly affected by temperature; however, it does not depend on the antidepressant concentration in the range of their therapeutic concentrations. The data analysis proved that the ratio of RBCs to plasma volume concentrations is the suitable parameter characterizing antidepressant distribution in whole blood. Significantly higher ratios of RBCs to plasma concentrations were found for demethylated metabolites of tricyclic antidepressants and in the case of citalopram. Citalopram showed the highest accumulation in intact RBCs and at the same time the lowest binding to isolated membranes. The binding of drugs to isolated erythrocyte membranes was much higher than in whole blood.

CONCLUSION: The concentration ratio of antidepressant in RBCs and in plasma is sensitive not only to the binding properties of plasma proteins and cell membranes, but also to changes in drug molecule, both in aminopropyl chain and in aromatic rings. This ratio is to a large extent characteristic of a particular antidepressant....

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Journal Article 2006; 27(3): 345-349 PubMed PMID: 16816835 Citation  Keywords:  Aged, Aged, 80 and over, Female, Humans, Immunohistochemistry, Male, Middle Aged, RNA, Messenger:analysis, Receptor, Endothelin A:genetics, Receptor, Endothelin B:genetics, Reference Values, Reverse Transcriptase Polymerase Chain Reaction, Tissue Distribu.   

OBJECTIVES: Endothelin is a potent peptide mediator that is synthesized by a number of cells. Previous studies have revealed the occurrence of endothelin in nerve cell bodies of some peripheral ganglia. Endothelin mediates its effects via two distinct receptor subtypes ETA and ETB. The present study was designed to investigate the presence of these two receptors in the human trigeminal ganglion.

METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to show the presence of mRNA encoding ETA and ETB receptors in the human trigeminal ganglion. To localize the protein immunocytochemistry with antibodies against the endothelin receptors was used.

RESULTS: Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed mRNA for both receptor subtypes in the human trigeminal ganglion. Immunocytochemistry revealed numerous cell bodies containing the ETA and the ETB receptor proteins.

CONCLUSIONS: The expression of ETA and ETB receptors in the human trigeminal ganglion suggests a role for endothelin in autonomic and sensory neural transmission....

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Comparative Study 2006; 27(3): 359-364 PubMed PMID: 16816831 Citation  Keywords:  Adult, Analysis of Variance, Circadian Rhythm:physiology, Estradiol:blood, Female, Follicular Phase:blood, Humans, Linear Models, Luteinizing Hormone:blood, Ovulation:blood, Periodicity, Progesterone:blood, Reference Values, Substance P:blood,.   

OBJECTIVES: In order to determine the exact pattern of plasma Substance P (SP) concentration during the LH preovulatory surge and the functional correlates which could exist between plasma SP, LH, 17 beta-estradiol (E2) and Progesterone, we performed a detailed analysis of changes in plasma SP concentration, during the critical phases of the LH preovulatory surge in the Human.

METHODS: The experimental study was performed in 21 women between the ages of 26 and 35 years. For each subject, blood samples were taken every 15 min, between 07:00 a.m. and 09:00 a.m. for 3 consecutive days when E2 plasma values reached at last 125 pg/ml. Then, each subject, according to the mean LH value of each day, was classified into one of the following groups: 1) the day before the day of the ascending phase, 2) the day of the ascending phase, 3) The day of the LH surge, 4) the day of the descending phase, 5) the day after the day of the descending phase.

RESULTS: Mean SP plasma values for the day of the LH peak, the day of the descending phase and the day after the day of the descending phase were all significantly higher than the values of the day of the ascending phase. Overall, there was an almost linear increase for plasma SP values between the day before the day of the ascending phase and the day after the day of the descending phase Also,this linear increase in plasma SP concentration exhibited a positive correlation (p = 0.016) with plasma progesterone concentrations which also started to increase on the day of the ascending phase of the LH surge.

CONCLUSIONS: Taken together with previous results which have shown that the administration of a SP antagonist reduces both the amplitude and the duration of the preovulatory LH surge in the monkey, the increase in plasma SP concentrations, possibly driven by the rise in serum progesterone concentration, which take place at the time of the preovulatory LH surge, is certainly an important element of the Hypothalamo-Pituitary-Gonadal interactive network necessary for the full development of the preovulatory LH surge in the Human....

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Comparative Study 2006; 27(3): 315-320 PubMed PMID: 16807524 Citation  Keywords:  Adolescent, Adult, Empathy, Exploratory Behavior:physiology, Female, Humans, Leadership, Male, Personality:physiology, Psychology, Adolescent, Reference Values, Saliva:physiology, Sex Factors, Social Dominance, Testosterone:physiology,.   

OBJECTIVES: In the present study, we tested the hypothesis that gender - dependent differences in novelty seeking, leadership, and sympathy might correlate with testosterone titre. Since several studies report that the impact of testosterone on personality traits is more visible under emotional challenging situations, we harvested saliva testosterone upon an anticipated stressor (academic examination) and under basal conditions.

SETTING AND DESIGN: 19 female and 23 male adolescents (17 to 19 years of age) completed standardized questionnaires on sensation seeking, anxiety, and social interaction. Two weeks later, they had to write an anticipated, rigorous examination in mathematics in their school. Before and after the examination, saliva had been harvested from each subject and testosterone titre has been estimated.

METHODS: Saliva testosterone was quantified using a luminescence immunoassay (LIA). Each subject completed questionnaires on sensations seeking according to Zuckerman (SSS - V), anxiety (STAI), and social interactions.

RESULTS: Both genders showed an increase in their testosterone titre shortly after examination or announcement of test scores. A Spearman correlation coefficient indicated a significant correlation between testosterone titre and sensation seeking subscales in female but not in male subjects. Analysis of social interactions revealed that peers regarded male subjects, who had high testosterone titres, as leaders but not as likeable individuals, whereas they regarded female subjects, who had high testosterone titres, not as leaders but as highly likeable individuals.

CONCLUSION: Theses findings strongly suggest that testosterone has gender specific effects on novelty seeking, dominance, and sympathy....

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