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Editorial 2003; 24(6): 401-403 PubMed PMID: 15073564 Citation  Keywords:  Attitude to Health, Health, Humans, Psychophysiologic Disorders:psychology, Quality of Life,.   

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Journal Article 2003; 24(6): 397-400 PubMed PMID: 15073563 Citation  Keywords:  Angiotensin II:analogs & derivatives, Animals, Antihypertensive Agents:pharmacology, Cell Division:drug effects, Female, Losartan:pharmacology, Pituitary Gland, Anterior:cytology, Rats, Rats, Wistar, Receptor, Angiotensin, Type 1:metabolism, Vasoconstrict.   

OBJECTIVES: The purpose of this study was to investigate the effect of angiotensin II (AII) and angiotensin IV (AIV, 3-8 fragment of AII) on the cell proliferation in the anterior pituitary of rat in vivo.

MATERIALS AND METHODS: The female adult Wistar rats, ovariectomized 10 days before experiment were injected intraperitoneally with saline, AII, AIV and AII or AIV together with losartan--the specific AT1 receptor subtype antagonist. Bromodeoxyuridine (BrDU) incorporation into anterior pituitary cell nuclei was used as the index of cell proliferation.

RESULTS: We observed the increased BrDU-labeling index (LI) in the anterior pituitary of rat treated with either AII or AIV. The proliferogenic effect of neither AII nor AIV was reversed by AT1 specific antagonist losartan.

CONCLUSIONS: AII and AIV stimulate the rat anterior pituitary cell proliferation in vivo. This action of both angiotensin peptides is connected with activation of receptor different from AT1 subtype....

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Journal Article 2003; 24(5): 348-349 PubMed PMID: 14647011 Citation  Keywords:  Adolescent, Amino Acids:blood, Delirium:blood, Hallucinogens:adverse effects, Humans, N-Methyl-3,4-methylenedioxyamphetamine:adverse effects, Substance-Related Disorders:blood,.   

: Recreational use of the illegal drug "ecstasy" has increased dramatically in recent years. We have measured 33 different plasma amino acids in ecstasy users and controls. Significant differences were found for phosphoserine, glutamate, citrulline, methionine, tyrosine and histidine. Resembling changes in the plasma amino acids have been described in acute transient polymorphous psychosis. Thus, alterations in plasma - methionine and phosphoserine or other amino acids could be involved in the psychical symptoms produced by MDMA....

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Journal Article 2003; 24(5): 345-347 PubMed PMID: 14647010 Citation  Keywords:  Animals, Antioxidants:pharmacology, Hyperthyroidism:drug therapy, Injections, Intraperitoneal, Male, Melatonin:pharmacology, Rats, Rats, Sprague-Dawley, Testis:drug effects, Testosterone:metabolism, Thyroid Gland:drug effects, Thyroid Hormones:metabolism,.   

OBJECTIVE: Melatonin has a general inhibitory effect on the reproductive system and thyroid functions. Testosterone secretion increases in parallel to thyroid hormones in hyperthyroidism. The aim of this study was to investigate the effects of melatonin application on total T3, T4 and testosterone in hyperthyroid rats.

METHODS: This study was performed on 4 groups each consisted of 6 male Spraque Dawley rats. Control group (G1); sham group (G2); applied 0.5 ml/day of serum physiologic intraperitoneally for 2 weeks, hyperthyroid group (G3); applied 0.3 mg/kg/day thyroxine intraperitoneally for 2 weeks, and hyperthyroid and melatonin supplemented group (G4); applied 0.3 mg/kg/day thyroxine and 3 mg/kg/day melatonin. Blood samples taken by way of decapitation were analysed for total T3, T4 and testosterone by RIA.

RESULTS: Serum total T3 and total testosterone levels were the highest in hyperthyroid group (G3), whereas in hyperthyroid and melatonin supplemented group (G4) were the lowest (P<0.001). Total T4 levels were higher in group 3 than group 1, 2 and 4 (P<0.001).

CONCLUSION: Results revealed that melatonin supplementation in hyperthyroidism suppress secretion of thyroid hormones and testosterone secretion....

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Journal Article 2003; 24(5): 339-340 PubMed PMID: 14647008 Citation  Keywords:  Blood Pressure, Blood Pressure Monitoring, Ambulatory:standards, Circadian Rhythm, Heart Rate, Humans, Hypertension:diagnosis, Seasons,.   

: The diagnoses of summer or winter hypertension in one and the same person can depend upon the clock hour of measurement....

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Journal Article 2003; 24(5): 325-328 PubMed PMID: 14647005 Citation  Keywords:  Aldosterone:urine, Blood Pressure:genetics, Genetic Markers, Humans, Hypertension, Renal:genetics, Insulin:genetics, Middle Aged, Minisatellite Repeats, Phenotype, Pilot Projects, Polymorphism, Restriction Fragment Length, Potassium:urine, Quantitative Tr.   

BACKGROUND: Blood pressure regulation is a complex process influenced by numerous environmental and genetic factors. Consequently, there's no cookie-cutter approach for the elucidation of of the genetic mechanism involved. One of the goals of molecular geneticists in the field of hypertension is to unravel the genetic architecture of blood pressure regulation.

METHODS: With the aim of identifying quantitative trait loci participating in the control of blood pressure, we carried out a pilot study on a sample population of middle-aged, U.S. Caucasians (44 subjects). The design of the study was to search for associations between clinical variables of blood pressure regulation pertaining to the renin-angiotensin-aldosterone system (systolic and diastolic blood pressures, urinary excretion of sodium, potassium and aldosterone, plasma renin activity) and a genetic marker at a candidate gene locus - the human insulin gene (INS) RESULTS: We observed significant associations between a variable number of tandem repeats (VNTR) marker (visualized as a biallelic, class I/class III marker system) localized at the 5' end of the human INS gene, and plasma renin activity and urinary sodium, potassium and aldosterone.

CONCLUSION: Our results indicate that between 6 and 10 QTLs with comparable effects could be involved in blood pressure regulation via the rennin angiotensin system....

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Journal Article 2003; 24(5): 314-320 PubMed PMID: 14647003 Citation  Keywords:  Animals, Bone Density, Female, Mandible:diagnostic imaging, Rats, Rats, Wistar, Superior Cervical Ganglion:surgery, Sympathectomy, Tomography, X-Ray Computed, Tooth Eruption:physiology,.   

OBJECTIVE: To assess the effect of local sympathectomy on mandibular bone during tooth eruption in rats.

METHODS: The effect of a unilateral superior cervical ganglionectomy (Gx) on morphometry of ipsi- and contralateral mandible and volumetric bone density (as assessed by peripheral computed tomography) was examined 30 days after surgery.

RESULTS: Only a few mandibular morphometric parameters decreased significantly after denervation in rats subjected to a unilateral Gx and a contralateral sham-operation. Mandibular volumetric bone density decreased significantly after sympathetic denervation. In a second experiment, carried out under conditions of unilateral unimpeded eruption of incisors performed ipsilaterally or contralaterally to a unilateral Gx, a significant interaction "denervation x type of eruption" was found for most morphometric parameters. Further analysis indicated higher morphometric indexes in denervated mandibles than in the innervated ones under impeded incisor eruption conditions, and lower morphometric indexes in denervated mandibles than in the innervated ones under unimpeded incisor eruption conditions. Unimpeded eruption augmented total volumetric bone density providing the innervation was intact and caused opposite effects on cortical volumetric bone density in the presence of innervation (increase) or absence of innervation (decrease). Trabecular volumetric bone density decreased significantly after sympathetic denervation.

CONCLUSION: The results support a role of the sympathetic nervous system in the regulation of bone remodeling....

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Journal Article 2003; 24(5): 310-313 PubMed PMID: 14647002 Citation  Keywords:  Animals, Antioxidants:pharmacology, Circadian Rhythm, Cyclin-Dependent Kinase Inhibitor p21, Cyclins:metabolism, Male, Melatonin:pharmacology, Rats, Rats, Wistar, Thyroid Gland:cytology,.   

OBJECTIVES: The cell-cycle (cc) is, in part, controlled by cyclin-dependent kinases (CDKs), which are activated after binding cyclins (positive regulators of cc). CDK inhibitors (CDKIs), such as p15, p16, p21, and p27, inhibit cyclin-CDK complex activity, and function as negative cell cycle regulators, blocking cell-cycle progression. The aim of our study was to examine the influence of late-afternoon (1600-1800) subcutaneous (s.c.) melatonin (Mel) injections, administered for 2 weeks, on the p21 expression in male Wistar rat thyroid follicular cells (TFC).

METHODS: In order to detect the anti-p21 antibodies, the DAKO LSAB2 Rat Kit/HRP (DAKO, USA) and DAKO Liquid DAB Substrate-Chromogen System (DAKO, USA) were employed.

RESULTS: No statistically significant changes of p21(LI) (p21 labelling index) values were observed in particular groups of the rats receiving Mel injections, in comparison to the controls. The statistical difference of p21(LI) values (p<0.03) was only observed between groups of rats, receiving Mel injections in the dose of 25 microg/daily and 100 microg/daily.

CONCLUSION: Melatonin - in the applied doses and in the experimental conditions without any factors revealing anti-DNA activity - did not change, in any statistical way, p21 expression in rat thyroid follicular cells, as compared to the control group....

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