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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....

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Comparative Study 2002; 23(5-6): 391-395 PubMed PMID: 12500159 Citation  Keywords:  Animals, Coloring Agents, Cytoprotection:drug effects, DNA:analysis, Disease Models, Animal, Drug Evaluation, Preclinical, Drug Therapy, Combination, Growth Hormone:therapeutic use, Heart:drug effects, Male, Melatonin:therapeutic use, Myocardial Infarctio.   

OBJECTIVE: To examine the cytoprotective effect of melatonin or recombinant human growth hormone (hGH) on the early phase of a running myocardial infarction in rats by using the Feulgen staining.

METHODS: Rats were subjected to surgical ligature of the left coronary artery or its sham-operation and were studied 1.5 3 h later. Melatonin was administered in the drinking water (100 microg/ml water) for 7 days before surgery. Recombinant hGH (2 IU/kg) was given ip at the time of surgery. Feulgen-stained histological cardiac sections were examined by light microscopy and image analysis.

RESULTS: Infarcted rats receiving vehicle exhibited large, diffuse cardiac lesions with a marked positivity for Feulgen reaction. About 18 20% of the total area recorded became injured 1.5 or 3 h after infarction, respectively. Infarcted rats treated with melatonin or hGH, or the combination of both, and killed 3 h after surgery, showed cardiac sections with scattered lesions and only a few isolated injured muscle fibers. A similar effectiveness of melatonin and hGH, alone or in combination, to decrease injured area by 86 87% and the number of cardiac lesions by 75 80% was observed.

CONCLUSION: A significant cytoprotective effect of melatonin or hGH is demonstrable in an early phase of myocardial infarction in rats....

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Case Reports 2002; 23(5-6): 387-390 PubMed PMID: 12500158 Citation  Keywords:  Analgesics, Non-Narcotic:therapeutic use, Anti-Anxiety Agents:therapeutic use, Anticonvulsants:therapeutic use, Antioxidants:therapeutic use, Benzodiazepines, Child, Preschool, Consanguinity, Disease Progression, Dronabinol:therapeutic use, Electroencepha.   

GOAL: The casuistic of a child suffering from late infantile neuronal ceroid lipofuscinosis (NCL) of the type Jansky-Bielschowsky aims to provide a description of possible therapeutic options for the severe spastic and the debilitating myocloni that occur within the context of this disorder. Moreover, it also should include a discussion of potential indications for the application of delta 9-Tetrahydrocannabinol (THC) (Dronabinol, Marinol) in childhood....

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Comment 2002; 23(5-6): 385-386 PubMed PMID: 12500157 Citation  Keywords:  Child, Preschool, Circadian Rhythm:physiology, Humans, Japan, Melatonin:analogs & derivatives, Photic Stimulation, Photoperiod, Saliva:chemistry, Sleep:physiology, Time Factors, Urine:chemistry,.   

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Journal Article 2002; 23(4): 335-340 PubMed PMID: 12195237 Citation  Keywords:  Animals, Anticonvulsants:pharmacology, Cell Division:drug effects, DNA:biosynthesis, Drug Interactions, Hepatocytes:drug effects, Male, Melatonin:pharmacology, Mutagens:pharmacology, Necrosis, Nitroparaffins:pharmacology, Propane:analogs & derivatives, Ra.   

OBJECTIVES: 2-Nitropropane (2-NP) is mutagenic in a number of short-term mutagenicity assays in vitro and in vivo, and is a potent hepatocarcinogen in rats. Many studies have determined that differences in the metabolism and disposition of the chemicals that produce mutagenicity were not responsible for their observed carcinogenic differences, but that carcinogenicity correlated with the ability of the respective isomer to induce cell proliferation in the target organ.

METHODS: Three groups of male rats (control, 2-NP-treated [4 mmol/kg] and 2-NP + melatonin [10 mg/kg]) were used in the current study. Cell proliferation was quantitated by incorporation of 3H-thymidine, detected by autoradiography, into newly synthesized DNA. Histopatholgical study was carried out to investigate the morphological changes.

RESULTS: Twenty four hours after 2-NP administration, there was an increase in the labelling index (LI) and grain count per labelled nucleus (GC/N) in the hepatocytes of 2-NP-injected rats versus those of control animals. The increase was 69.5% in LI and 29.4% in GC/N. Melatonin treatment, 30 minutes preceding 2-NP, reduced the increase in LI (44.4%) and GC/N (20.7%) when compared with 2-NP-treated rats. Histopathology revealed multiple focal areas of necrosis in the liver following 2-NP injection. In the lung, there was a mucinous degeneration of the bronchial epithelium. Melatonin treatment restored the histopathological changes in both the liver and lung and they are more or less normal.

CONCLUSION: Overall, these results seem to indicate that the stimulatory effect of 2-NP on the cellular proliferation and the rate of DNA synthesis in the liver may be one of mechanisms by which the carcinogen induces its carcinogenic action. Also, melatonin treatment strongly protects the studied organs against the toxic effect of 2-NP....

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Journal Article 2002; 23(4): 329-334 PubMed PMID: 12195236 Citation  Keywords:  Alkaloids:analysis, Animals, Bivalvia:chemistry, Chromatography, High Pressure Liquid, Ganglia, Invertebrate:chemistry, Isoquinolines:analysis, Mass Spectrometry,.   

UNLABELLED: Tetrahydropapaveroline and reticuline, isoquinoline alkaloids, were purified and identified in the pedal ganglia of the marine mollusk Mytilus edulis.

OBJECTIVES: To determine the presence of tetrahydropapaveroline and reticuline, isoquinoline alkaloids, in animal tissues previously shown to express opiate receptors.

METHODS AND RESULTS: This was achieved by high performance liquid chromatography coupled with electrochemical detection and finally identified by electro-spray ionization quadrupole time of flight mass spectrometry (Q-TOF). The expression of these two terahydroisoquinoline alkaloids in the animals neural tissue is at the level of 2.5+/-0.64 ng/ganglion and 1.8+/-0.52 ng/ganglion, respectively.

CONCLUSION: This finding suggests that morphine biosynthesis may occur in Mytilus neural tissues, and that the biosynthesis pathway may be similar to that reported in the poppy plant....

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Journal Article 2002; 23(4): 325-328 PubMed PMID: 12195235 Citation  Keywords:  Animals, Antineoplastic Agents:pharmacology, Astrocytes:cytology, Cerebral Cortex:cytology, DNA-Binding Proteins:metabolism, Gene Expression:drug effects, Glioma, Growth Inhibitors:pharmacology, Interferon-gamma:pharmacology, Interleukin-6:pharmacology, L.   

OBJECTIVES: The purpose of this study was to compare the effects of neurotrophic cytokines on the JAK/STAT transcription factors and the immediate early gene, c-fos, in C6 glioma cells and in primary astrocyte cultures.

METHODS: In this study we compared the effects of interleukin 6, leukemia inhibitory factor and interferon gamma on C6 glioma cells and on primary astrocyte cultures using electrophoretic mobility shift assay and quantitative solution hybridization/Northern Blot analysis.

RESULTS: We show that interleukin 6, leukemia inhibitory factor and interferon gamma treatment induce the nuclear STAT3 and STAT1 proteins to bind to the sis inducible element of c-fos in both C6 glioma cells and primary cortical astrocytes. Furthermore, quantitative solution hybridization and Northern blot analysis show the differential regulation of c-fos mRNA levels by interleukin-6 (8.1 and 4.0 folds) and leukemia inhibitory factor (5.4 and 3.2 folds) in C6 and astrocyte cultures (respectively). However, interferon gamma increases in c-fos mRNA levels (2.9 fold in both C6 and astrocyte cultures) were not significant in a one way ANOVA.

CONCLUSION: This study suggests that two initial cytokine signaling pathways are present and functional in C6 glioma cells and in primary astrocyte cultures....

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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....

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