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Journal Article 2001; 22(4): 255-262 PubMed PMID: 11524633 Citation  Keywords:  Animals, Circadian Rhythm:drug effects, Drug Administration Schedule, Growth Hormone:blood, Insulin-Like Growth Factor I:metabolism, Male, Melatonin:administration & dosage, Oscillometry, Osmolar Concentration, Pineal Gland:physiology, Rats, Rats, Wistar,.   

BACKGROUND: A relationship between circadian GH-IGF-I axis activity and pineal gland function in rats is not sufficiently elucidated, particularly in the aspect of melatonin (MEL) participation with relation to a possible mechanism of these dependencies.

OBJECTIVE: Influence of pinealectomy and long-term MEL administration on circadian GH-IGF-I axis function in male rats was evaluated. An attempt was also made to determine whether the effect of exogenous MEL is dependent on the pineal gland presence.

METHODS: Studies were performed in 192 sexually mature male Wistar rats, which were subjected to pinealectomy or sham operation. In half of the animals from each group MEL (Sigma, USA) in dose of 50 microg/ 100g b.m. was administrated intraperitoneally (daily between 5 and 6 pm during a 4-week period). Blood for RIA assays of MEL, GH and IGF-I concentrations was collected every 3 hours during a day-beginning at 8 am (rats killed by decapitation).

RESULTS: Significant influence of pinealectomy and exogenous MEL on a daily profile of endogenous MEL in rats was confirmed. Distinct, dependent on the time of the day anomalies in circadian oscillations of GH and IGF-I showing positive correlation with changes in endogenous MEL concentrations were also shown. GH rhythm was suppressed in a group of rats with removed pineal gland; after pinealectomy distinct decrease and after MEL use - distinct increase of GH and IGF-I concentrations during the day were observed. It had influenced mean daily concentrations and values of amplitude of circadian GH and IGF-I oscillations in all studied groups of animals. In rats with preserved pineal gland the effect of exogenous MEL action was more intensified.

CONCLUSIONS: Pineal gland can influence circadian function of GH-IGF-I axis, and in mechanism of this dependence, changes in endogenous MEL concentrations seem to play an important role. Administration of MEL in rats after pinealectomy only partly prevents changes of GH-IGF-I axis function caused by gland removal, which can indicate participation of other pineal gland substances in generating disturbances. Influence of exogenous MEL on GH-IGF-I axis function during the day is dependent on the presence of pineal gland, which can be connected with indirect and/or direct influence of administrated hormone on this gland....

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Journal Article 2001; 22(4): 251-254 PubMed PMID: 11524632 Citation  Keywords:  Aging:physiology, Animals, Circadian Rhythm, Endocrine System Diseases:drug therapy, Female, Macaca mulatta, Melatonin:blood, Nervous System Diseases:drug therapy, Oligopeptides:therapeutic use, Osmolar Concentration,.   

UNLABELLED: The OBJECTIVE of this research was to investigate the regulatory effect of Epitalon on the production of melatonin and cortisol in senescent monkeys.

MATERIAL AND METHODS: We investigated the character of melatonin and cortisol secretion by immunoferment assay in Epitalon-administered female Macaca mulatta in different age periods.

RESULTS: Epitalon was proven to significantly stimulate melatonin synthesis in senescent monkeys in the evening, thereby normalising the circadian rhythm of cortisol secretion....

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Journal Article 2001; 22(4): 248-250 PubMed PMID: 11524631 Citation  Keywords:  Adult, Contraceptives, Oral:pharmacology, Female, Humans, Hyperandrogenism:complications, Incidence, Italy, Menstruation Disturbances:complications, Multiple Sclerosis:complications, Reference Values,.   

: A mild prevalence of multiple sclerosis (MS) is present in females (2:1). To elucidate the pathogenetic role of sex steroids on the disease, we studied 76 women affected by MS, compared to 50 healthy women (mean age +/- SD, 34.9 +/- 0.9 vs. 33.4 +/- 1.7 years). The menarche was at mean age of 12.3 +/- 0.2 vs. 12.4 +/- 0.2. Interval between menses was 28.0 +/- 0.3 vs 27.8 +/- 0.3 days, with duration of menstrual flow of 5.0 +/- 0.2 vs. 5.0 +/- 0.2 days. Oligo- or amenorrhea was present in 20% of patients and in 16% of controls. Oral contraceptives were assumed by 21% of patients and 34% of controls (n.s.). Premenstrual symptoms were found in 43% of patients and in 46% of controls (n.s.). The incidence of hyperandrogenism (greasy skin, acne and hirsutism), evaluated by a specific questionnaire, was higher and statistically significant in MS patients than in controls (28% vs. 10%, p<0.05). Further studies, including a complete clinical and laboratory evaluation of gonadal function, are necessary in order to clarify whether hyperandrogenism may influence MS disease activity....

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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....

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Journal Article 2001; 22(4): 238-242 PubMed PMID: 11524629 Citation  Keywords:  Animals, Blood Glucose:analysis, Cholesterol:blood, Diabetes Mellitus, Experimental:metabolism, Hydrolases:metabolism, Insulin:blood, Kidney:enzymology, Liver:enzymology, Lysosomes:enzymology, Male, Rabbits,.   

OBJECTIVES: The study was carried out on fifty male rabbits of the New Zealand White breed. Diabetes was caused by a single, intravenous alloxan injection. Rabbits which had glycaemia 7th day after the alloxan administration higher than 11 millimol/litre were selected for the studies. They were divided into 5 groups: I - control (without diabetes); II - 3-week diabetes; III - 6-week diabetes; IV - 3-month diabetes; V - 6-month diabetes.

METHODS: In control and experimental rabbits the activity of beta-glucuronidase, N-acetyl-beta-glucosaminidase, lysosomal acid phosphatase, leucine aminopeptidase, cathepsin D, and lysosomal arylesterase was determined in lysosomal fractions of the liver and kidney.

RESULTS: Alloxan caused lowering of the activity of all the investigated enzymes in the kidney and liver except lysosomal arylesterase.

CONCLUSION: Alloxan injection caused a significant increase in the activity of all the investigated enzymes. The advisable lysosomal enzymes may be useful for the monitoring of the course and effectiveness of diabetes therapy....

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Comparative Study 2001; 22(4): 229-237 PubMed PMID: 11524628 Citation  Keywords:  1,2-Dimethylhydrazine:administration & dosage, Animals, Biogenic Monoamines:metabolism, Carcinogens:administration & dosage, Circadian Rhythm:drug effects, Dopamine:metabolism, Drug Administration Schedule, Female, Hydroxyindoleacetic Acid:metabolism, Inj.   

OBJECTIVES: Our data on the contents of norepinephrine (NE), dopamine (DA) and the metabolite of serotonin 5-hydroxyindoleacetic acid (5-HIAA) measured in the suprachiasmatic nuclei (SCN), preoptic area (PA) and median eminence (ME) of hypothalamus of rats after single subcutaneous injection of 1,2-dimethylhydrazine (DMH) as well as the effect of this carcinogen on formation of reactive oxygen species (ROS) in the PA are presented in this paper.

RESULTS: Diurnal changes of DA in all studied brain structures and of NE in the PA have been observed in the control group. Their morning levels were higher than evening ones. Rhythms of 5-HIAA in the SCN and diurnal changes of ROS formation have been shown to have contrary changes in control. Both the morning (11 a.m.) and evening (11 p.m.) subcutaneous administration of DMH at the dose of 21 mg/kg of body weight resulted in changes of all rhythms observed in control. In some cases a phase shift was found, in others the rhythms of neurotransmitters and ROS formation disappeared entirely.

CONCLUSION: The data obtained confirm the idea of dopaminergic and serotoninergic systems taking part in mechanisms of a response of the hypothalamic nuclei to non-photic stimuli. It is suggested that the effect of DMH on the content and diurnal rhythms of neurotransmitters in the hypothalamic structures under study is due to its affecting activities of the enzymes of biogenic amines synthesis, synaptic transmission, melatonin synthesis and secretion rhythms. The change in ROS formation that is caused by administration of DMH is likely to be due to a disturbance of diurnal rhythms of neurotransmitters that are one of the sources of formation of free radicals in the brain....

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Editorial 2001; 22(4): 219-221 PubMed PMID: 11524626 Citation  Keywords:  Cooperative Behavior, Culture, Europe, Humanities, Humans, Interprofessional Relations, Models, Theoretical, Research, Science,.   

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Journal Article 2001; 22(3): 192-198 PubMed PMID: 11449197 Citation  Keywords:  Adult, Affect, Antidepressive Agents:therapeutic use, Circadian Rhythm, Clomipramine:therapeutic use, Depression:blood, Female, Humans, Male, Melatonin:blood, Middle Aged, Sleep Wake Disorders:complications,.   

OBJECTIVES: The aim of the study was to establish if there are differences in the 24-hour melatonin secretion profile between patients with major depression (before, and after treatment with clomipramine) compared to those in healthy subjects. Additionally, we determined if there are differences in melatonin concentrations, depending on the severity of depression, and the presence of 24-hour rhythm disturbances.

MATERIAL AND METHODS: Twenty patients with major depression and 24-hour rhythm disturbances, and 14 healthy volunteers took part in the study. Before, and after treatment with clomipramine all subjects had blood samples collected at 08:00, 14:00, 20:00, 24:00, 02:00, 04:00, and 08:00 h, for estimation of melatonin concentrations. Before and after treatment, the severity of depression was evaluated using the following scales: the Hamilton Depression Rating Scale (HADRS), Beck Depression Inventory (BDI), and clinical observation, as well as presence, and if so, severity of 24-hour rhythm disturbances were assessed.

RESULTS: In individuals with major depression with marked disturbances of their diurnal rhythms, melatonin secretion is also disturbed, shown by the higher melatonin concentrations at night as compared to those in healthy individuals. However, melatonin levels were independent of the severity or the clinical manifestation of depression. Moreover, no correlation between the disturbances in their diurnal rhythms (sleep-watchfulness, diurnal mood shifts) and disturbed melatonin pattern was observed.

CONCLUSIONS: Melatonin nocturnal concentrations in patients with major depression were higher than those in healthy individuals. However, the melatonin concentration values do not differentiate the patients in terms of the severity of the depressive symptoms....

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