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Journal Article 2006; 27(Suppl 2): 164-167 PubMed PMID: 17159806 Citation  Keywords:  Animals, Antioxidants:pharmacology, Calcium:metabolism, Female, Flavonoids:pharmacology, Muscle, Skeletal:drug effects, Rabbits, Sarcoplasmic Reticulum Calcium-Transporting ATPases:metabolism,.   

OBJECTIVES: Effects of phenolic antioxidants, synthetized (trolox, pyridoindole stobadine) and plant extracts (EGb 761 and Pycnogenol) were investigated on the activity of Ca(2+)-ATPase from sarcoplasmic reticulum (SR) of rabbit skeletal muscle to examine their potency to modulate the activity of this calcium level regulating enzyme.

METHODS: SR vesicles and pure Ca(2+)-ATPase were isolated by ultracentrifugation. Ca(2+)-ATPase activity was measured spectrophotometrically by enzyme-coupled assay.

RESULTS: Pycnogenol (Pyc) significantly decreased the activity of Ca(2+)-ATPase incorporated into SR vesicles as well as the activity of purified Ca(2+)-ATPase, the latter with respect to both enzyme substrates, Ca(2+) and ATP. Trolox, stobadine and EGb 761 did not influence significantly the activity SR- vesicle incorporated or pure Ca(2+)-ATPase, the latter with respect to either substrate, in spite of alterations of kinetic parameters in some cases.

CONCLUSIONS: The decrease of SR Ca(2+)-ATPase activity induced by Pyc may be associated with its proapoptotic and anticancerogenic properties....

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Journal Article 2006; 27(Suppl 2): 116-120 PubMed PMID: 17159794 Citation  Keywords:  Brain Injuries:blood, Gene Expression Profiling, Humans, Magnetic Resonance Imaging, Metallothionein:blood, Nerve Growth Factors:blood, Phosphopyruvate Hydratase:blood, Radiography, S100 Calcium Binding Protein beta Subunit, S100 Proteins:blood,.   

OBJECTIVES: The aim of this study was to evaluate the correlation of neuron specific enolase (NSE), protein S100B and time-profile of Glasgow Coma Score (GCS) development with metallothionein (MT) blood levels in patients with traumatic brain injury (TBI) during 10 days of hospitalization. Patients were divided into 2 groups with respect to NSE and S100B levels - with (group I) and without (group II) GCS improvement.

METHODS: Serum NSE and S100B concentrations were measured by immunochemical methods; serum metallothionein concentration by electrochemical technique. Cortical biopsies were investigated immunohistochemically and by electron microscope. A cDNA microarray containing 700 gene probes was used to study the changes in gene expression in the ipsilateral cortex.

RESULTS: Values of MT in the blood of group I showed a non-significant decrease compared to group II during 1-3 days after admission. There was an increase of MT during 4-8 days in comparison with values of 1-3 days. The highest value of MT during hospitalization was found in a patient with diffuse axonal injury (group II). The data of cDNA microarray suggested an increase in expression of gene transcripts for oxygen free radical scavenger proteins corresponding with the increase of MT during 4-8 days in both groups.

CONCLUSIONS: The experimental data indicate that monitoring the content of MT in patients with trauma brain injury would be a suitable approach to evaluate the degree of injury or duration of prolonging unconsciousness, particularly in diagnosis of diffuse axonal injury....

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Case Reports 2006; 27(4): 547-548 PubMed PMID: 16892004 Citation  Keywords:  Adult, Brain Neoplasms:complications, Calcitriol:blood, Calcium:blood, Glioblastoma:complications, Humans, Hypercalcemia:blood, Male, Parathyroid Glands:physiology,.   

: Hypercalcemia is commonly associated with cancer, occurring in around 10-20% of cancer patients. Hypercalcemia is usually related to solid and non-solid malignancies specifically breast cancer, lung cancer and multiple myeloma. Hypercalcemia has been reported to occur in association with astrocytomas, and uncommonly in gliomas. We report a case of a previously healthy man presenting with glioblastoma multiforme . He was found to have persistently elevated serum calcium and calcitriol with normal parathyroid function. This is the first reported case of hypercalcemia associated with glioblastoma multiforme....

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Journal Article 2006; 27(1-2): 97-104 PubMed PMID: 16648781 Citation  Keywords:  Animals, Benzhydryl Compounds, Calcium:metabolism, Calcium Channel Blockers:pharmacology, Calcium Signaling:drug effects, Cells, Cultured, Estradiol:analogs & derivatives, Estrogen Antagonists:pharmacology, Estrogens, Non-Steroidal:pharmacology, Excitator.   

OBJECTIVES: Bisphenol A (BPA) is a typical endocrine disrupter. We investigated the mechanisms of rapid Ca(2+) signaling induced by a low dose BPA application in cultured hippocampal neurons.

MATERIALS AND METHODS: The primary culture of hippocampal neurons were prepared from postnatal 3 to 5-day-old rats. Cells were loaded with Calcium Green-1 fluorophore. Ca(2+) imaging and analysis were performed by Argus system.

RESULTS: The application of BPA at 10-100 nM induced a transient increase in the intracellular Ca(2+) of N-methyl-D-aspartate (NMDA)-responsive neurons. The Ca(2+) transient occurred within 30 sec after the BPA application. The proportion of BPA-responsive neurons was 9.6 % and 8.5 % of the total NMDA-responsive neurons, respectively, upon 10 nM and 100 nM BPA application. The pre-treatment of neurons with Ca(2+) channel blockers, thapsigargin and nifedipine, considerably decreased the proportion of BPA-responsive neurons to 0.7 % and 3.7%, respectively. The treatment of neurons with an antagonist of estrogen receptor, ICI 182,780, also significantly decreased the proportion of BPA-responsive neurons down to 1.1 %.

CONCLUSION: These results suggest that a low dose BPA application rapidly drives the Ca(2+) signaling system via activation of non-genomic pathway including estrogen receptors....

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Case Reports 2005; 26(4): 317-319 PubMed PMID: 16136018 Citation  Keywords:  Adult, Anticonvulsants:adverse effects, Calcium:administration & dosage, Carbamazepine:adverse effects, Epilepsy, Tonic-Clonic:complications, Female, Humans, Hypocalcemia:chemically induced, Intellectual Disability:complications, Tetany:chemically induced.   

OBJECTIVE AND METHODS: We presented a rare case of tetanic crisis in a 23-year old mentally retarded woman with epilepsy after treatment by oxcarbazepine, the new anticonvulsant agent. We reviewed laboratory, radiographic and medical examinations and recommend a proper treatment in such cases.

RESULTS AND CONCLUSION: The laboratory tests revealed only severe hypocalcemia. We described the potential role of oxcarbazepine in the induction of activity of cytochrome P 450 system of hepar and increases of less active metabolism of vitamin D. Supplementation of vitamin D and calcium in patients taking antiepileptic drugs is in the same case crucial....

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Journal Article 2002; 23(5-6): 432-436 PubMed PMID: 12500165 Citation  Keywords:  Adrenergic alpha-2 Receptor Antagonists, Adrenergic alpha-Antagonists, Adrenergic beta-Antagonists:pharmacology, Animals, Calcium Channel Blockers:pharmacology, Diabetes Mellitus, Experimental:chemically induced, Disease Models, Animal, Dose-Response Rela.   

OBJECTIVE: Ghrelin is a newly discovered peptide, which was first demonstrated in the epithelium of rat stomach. The purpose of the study was to examine the effect of ghrelin on glucagon secretion from pancreatic tissue fragments of normal and diabetic rats.

METHODS: Diabetes was induced by streptozotocin (60 mg Kg body weight 1) given intraperitoneally. Four weeks after the onset of diabetes, pancreatic fragments of normal and diabetic rats were incubated with different concentrations (10 12 10 6 M) of ghrelin. Glucagon release was measured using radioimmunoassay technique.

RESULTS: Ghrelin failed to stimulate or inhibit glucagon secretion from normal rat pancreas. However, it induced significant increases in glucagon secretion from pancreatic tissue fragments of diabetic rats. Either atropine (muscarinic cholinergic receptor antagonist) or propranolol (beta-adrenergic receptor antagonist) or yohimbine (alpha2-adrenergic receptor antagonist) or diltiazem (calcium channel antagonist) did not affect ghrelin-glucagon interaction. Moreover, a combination of atropine, propranolol and yohimbine had no significant effect on the interaction of ghrelin with glucagon.

CONCLUSION: The ghrelin-induced glucagon secretion in diabetic rats is not controlled via cholinergic or adrenergic pathways. In conclusion, it appears that the main target of ghrelin in the rat endocrine pancreas is not glucagon-producing cells but rather insulin secreting cells which are more involve in weight gain and body growth....

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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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Journal Article 2001; 22(3): 199-207 PubMed PMID: 11449192 Citation  Keywords:  Animals, Apamin:pharmacology, Calcium:pharmacology, Cyclooxygenase Inhibitors:pharmacology, Dinoprost:pharmacology, Female, In Vitro Techniques, Indomethacin:pharmacology, Melatonin:pharmacology, Oxytocin:pharmacology, Potassium Channels:drug effects, Pot.   

OBJECTIVE: The aim of this study was to investigate the effects of melatonin on spontaneous and oxytocin-induced contractility of pregnant and non-pregnant rat myometrium in vitro.

DESIGN: Myometrial strips were removed from virgin or late pregnant (21 days gestation) Wistar rats following decapitation and placed in an organ bath containing Krebs' solution at 37 degrees C and pH 7.4, constantly bubbled with 95% oxygen-5% carbon dioxide and isometric contractions were recorded. Effects of cumulative concentrations of melatonin (0.1 to 10 microM) on spontaneous and oxytocin-induced contractions were studied. Possible involvement of Ca(2+)-activated K (+) channels in inhibitory actions of melatonin was investigated by using apamin (100 nM).

RESULTS: Melatonin inhibited spontaneous and oxytocin-induced contractions of myometrium from both virgin and late pregnant rats in a dose-dependent manner. After inhibition of oxytocin-induced contractions by melatonin, application of prostaglandin F (2alpha) (1 microM) but not high KCl (30 mM) containing solution initiated contractile activity. Inhibitory response induced by melatonin (13 microM) was not affected by apamin (100 nM).

CONCLUSIONS: Data from this study demonstrates that melatonin inhibits spontaneous and oxytocin-induced contractions of myometrium from pregnant and non-pregnant rats. Although the exact mechanism is not clear, melatonin-induced inhibition of myometrial contractions may results from its interactions with Ca(2+) channels....

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