Electronic Library of Scientific Literature



ENDOCRINE REGULATIONS



Volume 32 / No. 2 / 1998




LONG-TERM EFFECTS OF VARIOUS IODINE AND FLUORINE DOSES ON THE THYROID AND FLUOROSIS IN MICE

W. Zhao, H. Zhu, Z. Yu, K. Aoki, J. Misumi, X. Zhang

Department of Environmental Hygiene, Hebei Medical University, Shijiazhuang 050017, China;
Department of Public Health and Hygiene, Oita Medical University, Oita 879-5593, Japan;
Department of Pathology, Hebei Medical University, Shijiazhuang 050017, China

Objective. To elucidate the participation of the independent and combined long term effect of various concentrations of iodine and fluorine on the pathogenesis of goiter and fluorosis in mice.
Methods. Nine drinking water supplies with different iodine and fluorine content were prepared by combination of potassium iodate and sodium fluoride solutions in bidistilled water. The concentrations of iodide were: 1. iodine deficiency (ID): 0.0; 2. iodine normal (IN): 20.0; 3. iodine excess (IE) 2500.0 Ág/l; and these of fluoride were: 1. fluoride deficiency (FD) 0.0; 2. fluoride normal 0.6; 3. fluoride excess (FE), 30.0 mg/l. A total of 288 Kunmim mice was divided into 9 groups consisting of 32 animals each and each group, in addition to basal diet, received one of following iodide/fluoride mixtures: ID+FD, ID+FN, ID+FE, IN+FD, IN+FN, IN+FE, IE+FD, IE+FN, IE+FE. By such manner, one half of the animals of each group was treated for 100 days and the other half for 150 days.
Results. It was found that ID only and IE only could both induce the goiter. FE induced dental fluorosis and increased fluorine content in the bone. In addition, fluorine also affected the thyroid changes induced by ID or IE. After 100 days of treatment, fluorine showed some stimulatory effect on the thyroid in ID conditions and inhibitory effect in IE conditions. After 150 days, however, the effects of fluorine on the thyroid reversed as compared with that of 100 days. On the other hand, difference of iodide intake could also increase the toxic effects of FE on the incisors and bones. The rate and degree of the incisor fluorosis, the fluorine contents in the bone were significantly higher in the ID+FE group than those in the IN+FE and IE+FE groups.
Conclusions. Both iodine deficiency and excess induced goiter as well as other functional and histopathological changes in the mouse thyroid. Excessive fluorine caused fluorosis of incisors and limb bones. In addition, iodine and fluorine do have mutually interacting effects on both goiter and fluorosis in the experimental mice.

Key words: Iodine - Fluorine -Various doses - Goiter- Fluorosis - Mice
Endocrine regulations, Vol. 32, 63 - 70, 1998

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DISTRIBUTION OF DOPAMINE TRANSPORTER IN THE RAT: AN IMMUNOHISTOCHEMICAL STUDY

T. Mitsuma, N. Rhue, Y. Hirooka, M. Kayama, T. Wago, Y. Mori, J. Takagi, K. Adachi, J. Ping, M. Ohtake, T. Nogimori, J. Sakai

Fourth Department of Internal Medicine,
Department of Laboratory Medicine and
the First Department of Physiology, Nagakute, Aichi, Aichi 480-11, Japan,
Department of Internal Medicine, Konanshowa Hospital, Konan Aichi, Japan

Objective. To investigate the organ distribution of dopamine transporter (DAT) in rats by immunohistochemical method.
Methods. Dopamine transporter (DAT) was identified immunohistochemically in the tissues using specific antipeptide antiserum raised in New Zealand white rabbits immunized with a conjugate of synthetic DAT peptide (29-45) with bovine serum albumin. Immunohistochemical analysis was performed by avidin-biotin complex method.
Results. DAT immunoreactivity was visualized in the neural perikarya, axons and dendrites of the central nervous system, retina, adrenal medulla, Auerbach's nervous branch and Meissner's nervous branch of the stomach, small intestine and colon, anterior pituitary, and lung. When using antiserum preincubated with synthetic DAT peptide (DAT, 29-45) or hypothalamus homogenate which contains DAT, no significant stain of neurons in the hypothalamus was detected.
Conclusion. These findings suggest that DAT is widely distributed and that the method used is valuable in studying the distribution of DAT in rats.

Key words: Dopamine transporter - Immunohistochemistry - Organ distribution - Rats
Endocrine regulations, Vol. 32, 71 - 75, 1998

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LONG-TERM EFFECTS OF EARLY POSTNATALLY ADMINISTERED INTERLEUKIN-1▀ ON THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS IN RATS

Andreas Plagemann, Alexander Staudt, Franziska G÷tz, Uwe Malz, Wolfgang Rohde, Annett Rake and GŘnter D÷rner

Institute of Experimental Endocrinology, Humboldt University Medical School (CharitÚ), Berlin, Germany.

Objective. Since perinatal stress events are well known to exert long-term influences on the function of hypothalamic-pituitary-adrenal (HPA) axis in rats, to investigate the consequences of exposure to IL-1▀, a potent stimulator of this axis, during early postnatal life.
Methods. Wistar rats were treated twice a day with 0.02 Ág human recombinant IL-1▀ from day 1-4 of age, while controls received the vehicle only.
Results. IL-1▀-treatment had no significant influence on the mortality and body weight. However, at the end of treatment period on the 4th day of life, the thymus weight was decreased in the IL-1▀-treated group (P<0.01), while the adrenals were clearly enlarged (P<0.0002). These responses were associated with a nearly 4-fold elevation of the plasma corticosterone (CS) level as compared to vehicle-treated controls (P<0.001). At the age of seven months the stimulated CS levels induced by an acute stress (novel environment) were lower in rats treated neonatally with IL-1▀ than in controls (P<0.01). This functional disturbance was associated with morphological alterations in the parvicellular part of the paraventricular nucleus (PVN) which is the main hypothalamic regulation centre of the HPA axis. A strong reduction of the numerical density of neurons was found in the neonatally IL-1▀-treated rats (P<0.005) while the neuronal nuclei were clearly enlarged (P<0.0005).
Conclusion. As a part of an infection-induced stress response during critical periods of development, IL-1▀ might be capable of inducing a permanent structural malorganization of the PVN and, consequently, functional malprogramming of the HPA axis in rats.

Key words: Interleukin-1▀ - Newborn rat - Long-term effects - Paraventricular hypothalamic nucleus (PVN) - Hypothalamic-pituitary-adrenal (HPA) axis.
Endocrine regulations, Vol. 32, 77 - 85, 1998

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SERUM LEVELS OF NEUROSTEROID ALLOPREGNANOLONE IN PATIENTS WITH PREMENSTRUAL SYNDROME AND PATIENTS AFTER THYROIDECTOMY

M. Bicikova, Z. Putz, M. Hill, R. Hampl, L. Dibbelt, J. Tallova, L. Starka

Institute of Endocrinology, Prague, Czech Republic;
Institute of Clinical Endocrinology, Luboch˝a, Slovak Republic;
Medizinische UniversitŃet zu Luebeck, Germany;
Faculty of Medicine, Masaryk University, Brno, Czech Republic

Objective. To evaluate whether altered levels of progesterone and its main neuroactive metabolite allopregnanolone do occur in premenopausal women. The second part of this study deals with allopregnanolone levels in thyreoidectomized women.
Methods. Allopregnanolone, a neurosteroid acting by its allosteric interaction with GABAA receptors and progesterone, were determined in two groups of patients which have in common certain psychic disorders generally characterized by the depression and anxiety, namely in 23 women with premenstrual syndrome (PMS) and in 52 women after total thyreoidectomy. The control groups consisted of women of the same age without premenstrual complaints and with normal thyroid function, respectively.
Results. Significantly lower values of allopregnanolone in PMS patients than in controls have been found in the follicular phase, indicating the lower peripheral activity of 5alpha-reductase of C21-steroids detectable at low progesterone levels only. In the thyroidectomized patients significantly higher values of allopregnanolone have been found in the luteal phase.
Conclusion. The increase of allopregnanolone level in thyroidectomized patients may represent one of the counterregulatory mechanisms protecting the organism from some consequences of hormonal disbalance after thyroid ablation.

Key words: Neurosteroids - Allopregnanolone - 5alpha-reductase - Premenopausal syndrome - Thyroidectomy
Endocrine regulations, Vol. 32, 87 - 92, 1998

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IN VITRO EFFECT OF TRIIODOTHYRONINE ON THE CYCLIC AMP, PROGESTERONE AND TESTOSTERONE LEVEL IN PORCINE THECA, GRANULOSA AND LUTEAL CELLS

E.L. Gregoraszczuk, J. Galas

Laboratory of Animal Endocrinology and Tissue Culture, Department of Animal Physiology, Institute of Zoology, Jagiellonian University, Krakow, Poland

Objective. To investigate the influence of thyroid hormone on steroid production and cAMP accumulation in porcine theca (Tc) and granulosa cells (Gc) isolated from preovulatory follicles as well as in luteal cells isolated during the mid-developing luteal phase.
Methods. Granulosa and theca cells separated from pig ovarian follicles and pieces of corpora lutea were cultured in the incubation medium M199 with 5 % calf serum. After the addition of triiodothyronine (T3) and 3-isobutyl-1-methyl xanthine (IBMX) to the culture medium cAMP, progesterone and testosterone were estimated with the aid of specific RIA.
Results. T3 added to the culture media stimulated the steroid secretion and cAMP accumulation in all cell types investigated. In theca cells, T3 alone increased androgen production by 2 fold and the addition of IBMX further augmented the steroidogenesis by 2.2 fold. In granulosa cell culture, IBMX had no effect either on the basal or T3 stimulated progesterone secretion and cAMP accumulation. In luteal cell culture, IBMX added alone increased progesterone secretion and cAMP accumulation in the same manner as T3. Further augmentation of progesterone secretion (1.3-fold) and cAMP accumulation (1.1-fold) was observed after the addition of IBMX together with T3.
Conclusion. The influence of thyroid hormone on cyclic nucleotide release by ovarian cells may suggest the involvement of cAMP-dependent mechanism in the realization of T3 action in ovarian cells.

Keys words: Triiodothyronine - cAMP accumulation - Progesterone - Testosterone - Theca, granulosa and luteal cells - Pig
Endocrine regulations, Vol. 32, 93 - 98, 1998

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IATROGENIC ADRENAL CORTEX FAILURE IN PATIENTS WITH STEROID DEPENDENT ASTHMA IN RELATION TO DIFFERENT METHODS OF GLUCOCORTICOID TREATMENT

B. Kos-Kudla

1st Department of Pathophysiology, Silesian Medical Academy, 41-800 Zabrze, Poland

Objective. To evaluate and compare the degree of adrenal cortex suppression in patients receiving long term treatment with different formulas and doses of glucocorticoids (GC) which is of considerable diagnostic and therapeutic importance.
Methods. A total of 97 subjects (51 women and 46 men) with bronchial asthma was divided into the groups subjected to different GC treatment (e.g. inhalation, oral and intramuscular GC). In all patients total blood serum and free salivary cortisol was estimated under basal conditions and after Synacthen stimulation as well as free cortisol and its metabolites in 24 hour urine.
Results. Reduced adrenal reserve was found in 58.33 % of patients chronically treated with systemic GC, in 21.05 % of patients periodically treated with systemic GC and in 9.09 % of patients treated with inhaled GC.
Conclusions. Inhaled GC caused a small degree of adrenal cortex suppression and thus should be preferred in the treatment of bronchial asthma. In addition, free salivary and urinary cortisol levels are a useful non-invasive method of evaluating adrenal cortex function in patients with bronchial asthma.

Key words: Glucocorticoid treatment - Adrenocortical function - Salivary cortisol - Serum cortisol - Urinary cortisol - Synacthen test - Bronchial asthma
Endocrine regulations, Vol. 32, 99 - 106, 1998

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COMMUNICATIVE CHARACTERISTICS OF REVIEWS OF SCIENTIFIC PAPERS WRITTEN BY NON-NATIVE USERS OF ENGLISH

M. Kourilova

Department of Foreign Languages, School of Medicine, Comenius University, Bratislava, Slovakia

Endocrine regulations, Vol. 32, 107 - 114, 1998

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