Search NEL Online

Journal Article 2003; 24(3-4): 224-226 PubMed PMID: 14523361 Citation  Keywords:  Animals, Cells, Cultured, Follicle Stimulating Hormone:metabolism, Luteinizing Hormone:metabolism, Male, Nerve Tissue Proteins:pharmacology, Pituitary Gland:cytology, Pituitary Hormones:metabolism, Prolactin:metabolism, Radioimmunoassay, Rats, Rats, Inbre.   

OBJECTIVE: Cocaine- and amphetamine-regulated transcript (CART) is widely expressed in the rat brain, especially in the hypothalamic nuclei and in the anterior pituitary. The aim of this study was to evaluate the effects of CART on pituitary hormone release in pituitary cell culture.

MATERIAL AND METHODS: The pituitary hormone release from pituitary cell culture after CART administration was investigated. Concentrations of LH, FSH, PRL, TSH and GH were measured with RIA methods.

RESULTS: CART in all doses (1 nMol, 10 nMol, 100 nMol) stimulated prolactin (PRL) release and inhibited TSH release. CART administration caused a dose dependent decrease in LH release. CART did not change GH release from cultured pituitary cells.

CONCLUSION: CART may affect directly pituitary hormones release in the cell culture....

Read abstract

Clinical Trial 2003; 24(1-2): 50-53 PubMed PMID: 12743532 Citation  Keywords:  Adult, Apomorphine:pharmacology, Disease Progression, Human Growth Hormone:blood, Humans, Hydrocortisone:blood, Male, Neoplasm Metastasis, Neoplasms:physiopathology, Neurosecretory Systems:drug effects, Prolactin:blood,.   

OBJECTIVES: The clinical approach of the Psychooncology is generally limited to the investigation of the only psychological status of cancer patients, without taking into consideration the well demonstrated cancer progression-related psychoneuroendocrine alterations, namely consisting of a progressive decline in the pineal endocrine function and an anomalous activity of brain opioid system. The endocrine response to apomorphine, a dopaminergic agent, has been proven to reflect the dopaminergic sensitivity, which would be involved at least in part in pleasure-related neurochemical mechanisms. The present study was performed to analyze the endocrine response to apomorphine in metastatic cancer patients, as a preliminary approach to the investigation of pleasure-related neuroendocrine mechanisms in human neoplasms.

MATERIALS & METHODS: The study included 10 metastatic cancer male patients and 6 male volunteers as a control group. Apomorphine was given orally at 0.01 mg/kg body weight in the morning, and venous blood samples were collected before, and at 20, 60 and 120 minutes after apomorphine administration. The endocrine analysis consisted of the measurement of serum levels of GH, PRL and cortisol.

RESULTS: All cancer patients presented alterations involving one or more endocrine responses to apomorphine. GH and cortisol mean levels after apomorphine were significantly higher in controls than in cancer patients, whereas no substantial difference occurred in those of PRL.

CONCLUSIONS: This preliminary study, by showing an altered endocrine response to apomorphine in metastatic cancer patients, would suggest that cancer progression may be associated with an altered dopaminergic sensitivity. Because of the involvement of the dopaminergic system in pleasure-related neurochemical mechanisms, this finding would demonstrated that the decline in the perception of pleasure with cancer progression may depend not only on psychological factors, but also, at least in part, on psychochemical alterations occurring during the clinical course of the neoplastic disease....

Read abstract  Full text PDF

Journal Article 2002; 23(5-6): 417-425 PubMed PMID: 12500163 Citation  Keywords:  Alkaline Phosphatase:blood, Animals, Biomarkers:blood, Bone and Bones:metabolism, Calcium:metabolism, Circadian Rhythm:physiology, Collagen Type I, Hormones:metabolism, Hydroxyproline:urine, Male, Melatonin:metabolism, Peptide Fragments:blood, Peptides, P.   

BACKGROUND: The mechanism of generating and synchronizing daily rhythms of bone and mineral metabolism markers has not been entirely explained. Most studies indicate that LD cycle and/or feeding schedules provide important synchronizers of these rhythms. It seems that endogenous factors, including systemic and local hormones can be important in the mechanism of dependence of bone and mineral metabolism parameters rhythms on LD cycle and feeding schedule.

OBJECTIVE: To assess the relationship between the daily profile of chosen biochemical parameters of bone and mineral metabolism (serum ALP, PICP, ICTP and iP and urinary excretion of HYP and total calcium) and daily secretion of MEL, GH/IGF-I axis activity and parathyroid, thyroid, adrenal cortex and gonads function in 48 adult male rats.

METHODS: Material for studies was collected every 3 hours within a day. Hormones, PICP and ICTP concentrations were determined with the use of RIA method and ALP, HYP, total calcium and iP values--spectrophotometrically.

RESULTS: Existence of a negative correlation between daily oscillations of studied markers of osteogenesis (ALP and PICP) and daily profile of MEL and PTH secretion and positive with daily fluctuations of GH and IGF-I was shown. Moreover, ALP values correlated negatively with daily oscillations of CT. Concentrations of bone resorption markers (ICTP, HYP and total calcium) correlated negatively with daily fluctuations of MEL and positively with GH, IGF-I and thyroid hormones.

CONCLUSION: The present results suggest that physiological daily rhythmicity of PTH, MEL, GH, IGF-I and thyroid hormones most probably play an important role in regulating the daily rhythm of biochemical markers of bone metabolism....

Read abstract  Full text PDF

Journal Article 2002; 23(4): 321-324 PubMed PMID: 12195234 Citation  Keywords:  Adjuvants, Immunologic:pharmacology, Animals, Carcinogenicity Tests, Dehydroepiandrosterone:pharmacology, Estradiol:pharmacology, Female, Galanin:genetics, Gene Expression:drug effects, Pituitary Gland, Anterior:drug effects, Prolactin:blood, RNA, Messeng.   

OBJECTIVES: The effects of dehydroepiandrosterone (DHEA) on galanin (GAL) and prolactin (PRL) mRNA expression in the anterior pituitary of Fischer 344 rats were studied, taking in consideration that: (1) DHEA is an androgen with estrogenic activity on pituitary lactotrophs; (2) estrogens induce prolactinomas in Fischer 344 rats; and (3) GAL has been considered the main mediator of estrogen-induced lactotroph proliferation.

DESIGN: Female rats were ovariectomized and used as controls or treated during 2 weeks with DHEA (500 mg/kg/day or 5 mg/kg/day or 50 mg/kg/day) or estradiol (E2, 50 microg/kg/day), as a positive control for pituitary growth and GAL induction. GAL and PRL mRNA expression were studied by in situ hybridization.

RESULTS: Both DHEA and E2 induced PRL mRNA synthesis. However, DHEA neither produced pituitary enlargement nor GAL induction, in contrast to E2.

CONCLUSIONS: Our results shows that GAL is not involved in the estrogenic activity of DHEA on pituitary lactotrophs, and suggest that DHEA effects are exerted directly on the PRL gene or through another mechanism(s) not related to GAL....

Read abstract

Clinical Trial 2002; 23(1): 61-63 PubMed PMID: 11880864 Citation  Keywords:  Aged, Androgen Antagonists:therapeutic use, Anilides:therapeutic use, Humans, Levodopa, Male, Middle Aged, Nitriles, Prolactin:blood, Prostatic Neoplasms:blood, Tosyl Compounds,.   

OBJECTIVES: The secretion of prolactin (PRL), which is a growth factor for prostate cancer cell proliferation, has been proven to present profound alterations in advanced prostate cancer patients, consisting of abnormally elevated baseline levels and paradoxical response to L-dopa. Moreover, the efficacy of standard therapies for prostate cancer may be mediated at least in part by changes in PRL secretion. The present study was carried out to analyze the effects of the new antiandrogen agent bicalutamide on basal levels of PRL and on its response to L-dopa in metastatic prostate cancer patients.

MATERIAL & METHODS: The study included 10 metastatic prostate cancer patients. They were treated with bicalutamide at a dose of 50 mg/day orally. They were investigated with L-dopa test before therapy and after one month of treatment. L-dopa was given orally at 500 mg, by collecting blood samples before and at 60, 120 and 180 minutes after L-dopa administration. Serum levels of PRL were measured by the RIA method.

RESULTS: Abnormally basal levels of PRL were seen in 4/10 (40%) patients. Mean PRL basal levels decreased after bicalutamide therapy, without, however, significant differences. Before therapy, a paradoxical increase in PRL levels after L-dopa occurred in 4 patients, 3 of them showed basal concentrations of PRL within the normal range. Moreover, bicalutamide therapy significantly reduced PRL increase in response to L-dopa.

CONCLUSIONS: This study would suggest that the measurement of the only basal levels is not sufficient to define as normal the secretion of PRL in advanced prostate cancer, because of the possible existence of altered response to the dynamic tests for PRL secretion. Moreover, the study shows that the antitumor therapy with the new anti-androgen bicalutamide may reduce PRL secretion and improve its paradoxical secretion in response to L.-Dopa. Further studies will be required to better define the possible prognostic impact of changes in PRL secretion on the efficacy of treatments for metastatic prostate cancer....

Read abstract  Full text PDF

Journal Article 2001; 22(4): 243-247 PubMed PMID: 11524630 Citation  Keywords:  Adult, Anti-Anxiety Agents:therapeutic use, Anxiety Disorders:drug therapy, Genitalia, Male:drug effects, Gonadotropins:blood, Humans, Hypothalamo-Hypophyseal System:drug effects, Isoindoles, Male, Middle Aged, Piperazines:therapeutic use, Prolactin:blood.   

BACKGROUND: Serotonin (5-HT) agonists are reported to affect prolactin (PRL) and gonadotropin secretion. A small study was conducted on male patients with generalized anxiety disorders to investigate the clinical and neuroendocrinological effects of the 5-HT(1A) receptor agonist tandospirone (TDS) on the hypothalamo-pituitary-gonadal (HPG) axis.

METHODS: The subjects for the present study included 11 male outpatients. Informed consent was obtained from all subjects involved in this study. The endocrine studies were done before and during TDS administration. Psychiatric ratings were done using the Japanese version of the Spielberger's State-Trait Anxiety Inventory.

RESULTS: We found that both state- and trait-anxiety scores were significantly reduced by TDS treatment; there was no significant difference in PRL, gonadotropins or testosterone (T) between the patients and normal controls; TDS administration showed significant stimulatory effects on PRL and T; and PRL change between baseline and TDS steady state (DeltaPRL) did not show a significant correlation with improvement in state or trait-anxiety scores.

CONCLUSIONS: Our results indicate that PRL response may not provide a clinical predictor; (2) PRL level may not reflect the level of anxiety, and 5-HT(1A) may have stimulatory effects on PRL. However, further, double-blind evaluation with a larger sample would be needed for clarification of effects of 5-HT(1A) on the HPG axis....

Read abstract  Full text PDF

Journal Article 2001; 22(3): 208-214 PubMed PMID: 11449193 Citation  Keywords:  Animals, Corticosterone:blood, Cytokines:blood, Hormones:blood, Inflammation:blood, Interleukin-10:blood, Interleukin-6:blood, Kinetics, Leptin:administration & dosage, Lipopolysaccharides:administration & dosage, Luteinizing Hormone:blood, Male, Prolacti.   

OBJECTIVES: In many studies it has been reported, that leptin may play an important role not only in the regulation of food intake and body weight but can modify immune response. The aim of our study was to estimate the effects of the administration of exogenous leptin on serum concentration of proinflammatory cytokines (interleukin 6-IL 6 and tumor necrosis factor alpha-TNF alpha) and anti-inflammatory cytokine (interleukin 10 - IL 10) during LPS induced acute inflammation. We also estimated leptin's influence on pituitary, thyroid, adrenal and gonadal hormones in response to lipopolysaccharide (LPS) induced acute inflammation.

METHODS: Male rats Wistar-Kyoto were divided into four groups, which received respectively: placebo (0.9% NaCl), LPS, leptin and leptin with LPS. The TNF alpha and IL 6 serum concentrations were measured after 2 hours and IL 10 after 4 hours. The pituitary, thyroid, adrenal and gonadal hormones serum concentrations were measured after 2 and 4 hours. Cytokine concentrations were estimated using ELISA tests and hormones concentrations using RIA tests.

RESULTS: Leptin did not have an effect on both cytokine responses (proinflammatory and anti-inflammatory) in the time of LPS-induced acute inflammation. Leptin enhanced LPS-induced increasing of corticosterone secretion after 2 hours and decreased LPS-induced inhibition of testosterone secretion after 4 hours.

CONCLUSIONS: Leptin can modulate hormone response during LPS-induced acute inflammation....

Read abstract  Full text PDF

Journal Article 2001; 22(2): 137-141 PubMed PMID: 11335890 Citation  Keywords:  Adult, Circadian Rhythm, Female, Humans, Hydrocortisone:secretion, Male, Melatonin:secretion, Pineal Gland:secretion, Prolactin:secretion, Reference Values, Schizophrenia:physiopathology,.   

OBJECTIVES: Recent studies have suggested the involvement of the pineal gland and its main hormone melatonin (MLT) in the pathogenesis of psychiatric disturbances, namely the depressive syndrome. In contrast, the behavior of MLT secretion in schizophrenia is still controversial.

MATERIAL & METHODS: The present study was carried out to analyze light/dark rhythm of MLT secretion in relation to that of cortisol and prolactin (PRL) in schizophrenic patients. The study included 13 schizophrenic patients, 8 of whom were untreated, while the other 5 patients were on neuroleptic therapy. Serum levels of MLT, PRL and cortisol were measured by RIA on venous blood samples collected at 8 A.M., 12 A.M., 8 P.M. and 1 A.M. The control group consisted of 20 age-matched healthy subjects.

RESULTS: A physiological nocturnal increase in MLT levels occurred in 6/13 patients, whereas the other 7 patients showed an abnormally low MLT peak during the night. Moreover, both light and night mean levels of MLT were significantly lower in patients than in controls. In addition, mean nocturnal levels of MLT were significantly lower in chronic patients than in those evaluated at the onset of disease. Cortisol rhythm was normal in 11/13 patients, whereas PRL levels were abnormally high in 10/13 patients.

CONCLUSIONS: This preliminary study would suggest that schizophrenia may be associated with a diminished secretion of MLT from the pineal gland, and pineal deficiency would be more evident in the chronic disease. Finally, pineal alterations have appeared to be associated with an altered secretion of PRL and cortisol, by suggesting that the schizophrenic disease may be characterized by marked neuroendocrine disturbances, whose physio-pathological and prognostic significance needs to be established by successive clinical investigations....

Read abstract  Full text PDF