Search NEL Online

Journal Article 2005; 26(5): 453-458 PubMed PMID: 16264391 Citation  Keywords:  Animals, Animals, Newborn:physiology, Arcuate Nucleus of Hypothalamus:cytology, Body Weight:physiology, Eating:physiology, Electrophysiology, Hypothalamic Hormones:pharmacology, Hypothalamus:cytology, In Vitro Techniques, Intracellular Signaling Peptides .   

OBJECTIVES: Hypothalamic neurons of rats overweight due to early postnatal overfeeding (SL) differ from those of control rats in their responses to feeding relevant hormones like leptin or insulin. The question arose whether prolactin and prolactin-releasing peptide (PrRP) express also differential action in SL rats. These peptides are described to have an effect on food intake and body weight regulation. Prolactin is co-synthesized in lateral hypothalamic neurons together with orexins that were also analyzed in this study.

METHODS: Single unit activity was extracellularly recorded in brain slices from adult control rats (CL) and from rats previously raised in small litters (SL). The action of the peptides on the firing rates was evaluated in the medial parvicellular part of the paraventricular nucleus (PaMP) and the medial arcuate nucleus (ArcM).

RESULTS: In control rats, PrRP significantly activated PaMP neurons, whereas prolactin and orexin-A induced also inhibition. In SL rats, there was a significantly different effect of orexin-B on PaMP neurons: the main effect changed from activation in controls to inhibition. ArcM neurons of both control and SL rats were mainly excited by prolactin and orexins.

CONCLUSION: Changes acquired during early development of neuronal responses to feeding relevant peptides are not a general non-specific mechanism of neurochemical plasticity, but concern specific hypothalamic nuclei and/ or hormones and neuropeptides. The increase in inhibition by orexin-B of hypothalamic paraventricular neurons could in vivo contribute to the neonatally acquired disposition towards persistingly increased food intake and reduced energy expenditure of overweight SL rats....

Read abstract  Full text PDF

Comparative Study 2005; 26(5): 459-462 PubMed PMID: 16264390 Citation  Keywords:  Animals, Female, Injections, Intravenous, Injections, Intraventricular, Leptin:administration & dosage, Ovariectomy, Pituitary Hormones:blood, Radioimmunoassay, Rats, Rats, Inbred WKY,.   

OBJECTIVE: It has been reported that leptin plays an important role in the regulation of food intake and energy expenditure. There are controversial opinions about effects of leptin on the hormonal system. The aim of this study was to estimate the effect of leptin on pituitary hormones release after central and peripheral administration.

METHODS: Leptin was injected intracerebroventricularly (icv) in a dose of 0.5 microg/5microl aCSF (artificial cerebrospinal fluid) for 5 min in Wistar Kyoto rats. At 60 and 120 min after injections the animals were decapitated. Leptin in a dose of 10 microg in 300 microl of saline was administered intravenously (i.v). At 60 mins the animals were decapitated. Serum rLH, rFSH, rPRL, rTSH, rGH concentrations were measured with RIA methods.

RESULTS: After central (icv) injection of leptin we observed an increase of rGH, rTSH and a decrease of rPRL. However, after peripheral (iv) injection of leptin we found a decrease of rGH and rTSH and an increase of rPRL. We did not find any significant changes in LH and FSH after icv and iv injection of leptin.

CONCLUSIONS: The opposite effects of leptin on pituitary hormones release were observed due to the method of leptin administration. Leptin may play a modulating role in the mechanism of pituitary hormones release....

Read abstract  Full text PDF

Comparative Study 2005; 26(5): 463-467 PubMed PMID: 16264389 Citation  Keywords:  Animals, Bombesin:administration & dosage, Cells, Cultured, Female, Injections, Intravenous, Injections, Intraventricular, Ovariectomy, Pituitary Gland:drug effects, Pituitary Hormones:blood, Rats, Rats, Inbred WKY,.   

OBJECTIVES: Functional studies indicate that bombesin may be involved in many physiological functions, including sensory transmission, the regulation of central autonomic pathways, thermoregulation, secretion of pituitary hormones, gastric and pancreatic secretion, food intake and satiety.

MATERIAL AND METHODS: In order to evaluate the role of bombesin in the mechanism of pituitary hormones release the effects of bombesin on rGH, rTSH, rPRL, rFSH and rLH release were investigated in female Wistar-Kyoto rats. In studies 'in vitro' bombesin in a dose of 1nM, 10nM, 100nM was administered to pituitary cell culture. After 60, 120, 240 min. of incubation pituitary hormones were measured. In studies 'in vivo' bombesin was injected intraventricularly (icv) in a dose of 0.5 microg/5 microl aCSF (artificial cerebrospinal fluid) for 5 min. (experiment I). In experiment II bombesin was administered intravenously (iv) in a dose of 10 microg. After 60 min, 120 mins the animals were decapitated and serum rGH, rPRL, rTSH, rLH, rFSH concentrations were measured with RIA methods.

RESULTS: Bombesin stimulated rLH, rPRL, rTSH release from cultured pituitary cells. A slight increase of GH was also observed. After intravenous (iv) injection of bombesin an increase in serum rPRL and rGH levels was found. However, the intraventricular (icv) administration of bombesin leads to decrease of serum rGH, rPRL and rTSH concentrations.

CONCLUSION: Our studies 'in vitro' and 'in vivo' indicate that bombesin may be involved in the modulation of pituitary hormones release....

Read abstract  Full text PDF

Journal Article 2005; 26(Suppl 1): 49-65 PubMed PMID: 16361988 Citation  Keywords:  Antidepressive Agents, Second-Generation:administration & dosage, Antipsychotic Agents:administration & dosage, Bipolar Disorder:drug therapy, Clinical Trials as Topic, Humans, Treatment Outcome,.   

: Conventional antipsychotic drugs, although efficacious in the treatment of mania, have not demonstrated a significant usefulness in the maintenance treatment of bipolar disorder. This has primarily been due to a tendency to induce depressive symptoms and depressive recurrences in this group of patients in the course of long-term administration. However, the picture has changed following the introduction of second-generation antipsychotics. These drugs have pro-depressant properties (if any) that are much weaker than conventional antipsychotics. Furthermore, their tolerability, especially in long-term treatment, is more favorable compared to classical antipsychotics. Clinical observations of the action profile of second-generation antipsychotic drugs in the treatment of schizophrenia have pointed to a possibility of these agents possessing mood-stabilizing properties. The first such suggestion was made by Zarate (1995) in connection with clozapine. The prevention of manic and depressive recurrences in bipolar disorder is a hallmark of the definition of mood-stabilizers....

Read abstract

Journal Article 2005; 26(Suppl 1): 27-47 PubMed PMID: 16361987 Citation  Keywords:  Antidepressive Agents, Second-Generation:therapeutic use, Antipsychotic Agents:therapeutic use, Bipolar Disorder:drug therapy, Clinical Trials as Topic, Depressive Disorder:diet therapy, Humans, Treatment Outcome,.   

: Antidepressants have insufficient effect in 20-40% of patients treated for depressive disorders. This is particularly true for psychotic and agitated depression. When administered on a long-term basis, antidepressants cause a switch into mania in 25-40% of patients and induce rapid cycling. Classical antipsychotics have exhibited good therapeutic efficacy in the treatment of various forms of depression, especially psychotic and agitated forms, albeit burdened with many, above all extrapyramidal, side effects. When administered over long periods of time, classical antipsychotics may have a depressogenic effect. Second-generation antipsychotics have started to be increasingly used in this indication for a variety of reasons including: their antidepressant effect attributable to raised concentrations of catecholamines in the prefrontal cortex, their impact on serotonin transmission, their antipsychotic effect due to their mode of action including the mesolimbic blockade of dopamine D2 receptors, and the low incidence of extrapyramidal and other side effects. The following text encompasses the results of controlled trials using second-generation antipsychotics in the treatment of acute depressive disorders....

Read abstract

Journal Article 2005; 26(Suppl 1): 9-25 PubMed PMID: 16361986 Citation  Keywords:  Acute Disease, Antidepressive Agents, Second-Generation:therapeutic use, Antimanic Agents:therapeutic use, Antipsychotic Agents:therapeutic use, Bipolar Disorder:drug therapy, Double-Blind Method, Drug Therapy, Combination, Humans, Randomized Controlled T.   

: The DSM-IV criteria for mania require: a distinct period that represents a break from pre-morbid functioning, a duration of at least one week, elevated or irritable mood, at least three to four classical manic signs and symptoms and the absence of any physical factors. Although not specifically mentioned in the ICD-10 or the DSM-IV definitions, delusional, hallucinatory, even first-rank, psychotic experiences can occur in mania. Acute mania can be subdivided into classical pure mania, mania with mood-congruent or mood-incongruent psychosis, mixed state and rapid-cycling mania. One quarter to two thirds of all manic episodes are associated with delusions, while 13% to 40% are associated with hallucinations. Mixed episode is a complex syndrome which is difficult to diagnose, has the most prolonged duration of bipolar episodes and more frequent psychotic profile than pure mania with high suicidality and poor response to drugs. Mixed state mania has been well known since Kreapelin and listed in classification systems with criteria that include both a manic and a major depressive episode nearly every day for at least a one-week period. On the other hand, mixed-like episodes that are clearly caused by somatic antidepressant treatment (e.g., medication, electro-convulsive therapy or light therapy) should not contribute toward a diagnosis of Bipolar I Disorder. Although, theoretically, mania is supposed to be resolved within 1-3 months even without treatment, psychiatric hospitalization is very common in especially severe cases due to functional impairment. Current treatments for mania aim to control the agitation, impulsivity, aggression and psychotic symptoms and to help patients regain their pre-morbid functionality. However, the clinical management of mania is challenging as most patients show syndromal remission but incomplete functional recovery after the first episode of mania....

Read abstract

Journal Article 2005; 26(4): 277-282 PubMed PMID: 16136024 Citation  Keywords:  Adult, Antibodies:immunology, Dental Amalgam:adverse effects, Female, Humans, In Vitro Techniques, Infertility:epidemiology, Interferon-gamma:metabolism, Lymphocyte Activation:drug effects, Lymphocytes:drug effects, Male, Mercury Poisoning, Nervous System.   

INTRODUCTION: Heavy metals can negatively influence the reproduction due to the fact that they are able to impair the immune reactions including autoantibody production in susceptible individuals. In such a way the infertility could be also caused by altered pathologic immune reaction.

AIM OF THE STUDY: To investigate the in vitro lymphocyte reaction after stimulation with metals and production of gamma interferon and antisperm antibodies in supernatants after lymphocyte stimulation in patients with infertility and with proven antisperm antibodies in their serum. The cause of antisperm antibodies presence was not determined.

METHODS: The diagnosis of metal allergy was performed by the lymphocyte proliferation method modified for metals (MELISA) in supernatants of tissue cultures of lymphocytes without the antigen stimulation and after stimulation with mercury chloride, the in vitro production of gamma interferon and antisperm antibodies was studied by ELISA.

RESULTS: More than 50% of patients were reacting to mercury, iron, aluminium and silver as mean by lymphocyte reactivity. When compared the lymphocyte reaction in patients with and without mercury allergy we found that the lymphocytes of patients with mercury intolerance produced less gamma interferon and more antisperm antibodies in supernatants after mercury stimulation of their lymphocytes.

CONCLUSION: In patients with metal intolerance diagnosed by the MELISA test the release of metal ions from dental materials can be one of the stimulating factors which may adversely affect fertility....

Read abstract  Full text PDF

Journal Article 2005; 26(4): 297-300 PubMed PMID: 16136023 Citation  Keywords:  Adult, Estradiol:blood, Female, Follicle Stimulating Hormone:blood, Glycolysis:physiology, Humans, Leptin:blood, Luteinizing Hormone:blood, Menstrual Cycle:physiology, Physical Exertion:physiology, Progesterone:blood,.   

OBJECTIVES: It was aimed to determine whether there was a difference in the leptin levels and short term exercise performance during the menstrual cycle of the young females who had normal menstrual cycle and no pregnancy story.

SETTING AND DESIGN: Fifteen sedentary females aged 19-23 yrs were included. All had regular menstrual cycle of 28-30 days and no pregnancy story. Blood samples were taken for the analysis of serum estradiol, progesterone and leptin levels and Wingate test was applied on a Monark 818E ergometer with 75 g/kg load on the 7th, 14th and 21st cycle days, randomly.

RESULTS: The differences in serum leptin levels and peak power, mean power and fatigue index during these days and the correlations between serum leptin and FSH, LH, estradiol and progesterone levels were not significant.

CONCLUSIONS: We concluded that performance in a short intense exercise which require high motivation is not affected by menstrual cycle and in young females with normal menstrual cycle, serum leptin concentration does not change during the cycle. Further studies constituting more standard groups, controlling food intake, timing the blood sampling, studying more days of menstrual cycle will help to obtain more accurate results....

Read abstract  Full text PDF