Electronic Library of Scientific Literature Electronic Library of Scientific Literature
Volume 34 / No. 3 / 2000
J. Brtko, A. Hartl, R. Weiss, S. Scheiblhofer, S. Mostboeck, J. Thalhamer
Institute of Experimental Endocrinology, Slovak Academy of Sciences, 833 06 Bratislava,
Slovakia
Institute of Chemistry and Biochemistry, Immunology Group, University of Salzburg, A-5020
Salzburg, Austria
E-mail: ueenbrtk@savba.savba.sk
Objective. Evaluation of the dynamics of all-trans retinoic acid receptor binding
properties in mouse spleen nuclear extracts during a primary immune response against
beta-galactosidase.
Methods. Female BALB/c mice, aged between 5 and 6 weeks were immunized
intradermally into the shaved back (4 spots each) with 100 microg beta-galactosidase in
100 microl sterile phosphate buffered saline (pH 7.2) and blood was taken by tail bleeding
on days 0 (preimmune serum), 4 and 6. Production of antibody in serum and the detection of
cytokines (IL-4, IFN-gamma) from proliferation supernatants were determined by ELISA.
Antigen-specific proliferation assay of isolated spleen cells was based on [3H]-thymidine
incorporation measured in a liquid scintillation counter. Both, the maximal binding
capacity (Bmax) and the afinity (Ka) of all-trans retinoic acid
nuclear receptors (RAR) were evaluated according to Brtko (1994).
Results and conclusions. Injection of beta-galactosidase induced the first
detectable antibody responses on day 4 (IgM) and on day 6 (IgG). These points of time,
reflecting the early and the mature immune response served to measure the antigen-specific
proliferation and production of IL-4 and IFN-gamma in the supernatants of the
proliferation cultures as well as all-trans retinoic acid receptor (RAR) binding
characteristics in spleen nuclear proteins. The RAR Bmax was significantly
(P<0.05) decreased only at the time of the first specific IgG antibody production.
Conclusions. The data obtained indicate the involvement of RAR in the late phase of
an in vivo immune response.
Key words: BALB/c mice Protein immunization beta-galactosidase Immune
response Nuclear retinoic acid receptor
Endocrine Regulations, Vol. 34, 113118, 2000
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Macho L., Fickova M., Zorad S., Sebokova E., Klimes I.
Institute of Experimental Endocrinology, Slovak Academy of Sciences, 833 06 Bratislava,
Slovakia
E-mail: ueenmach@savba.savba.sk
Objective. To test the effects of novel oral hypoglycemic agent A-4166 on lipolysis
and lipogenesis in adipocytes from normal rats and non-obese, hypertriglyceridemic,
insulin resistant and hypertensive rats (HTG) fed basal or high fat diet.
Methods. Adult male Wistar rats and hereditary HTG rats (from our own colony) were
used. They were fed either basal or high fat diet for three weeks. On the day of
observation the active substance A-4166 was administered intragastrically by gavage 30
minutes before decapitation. Blood was collected for the determination of insulin,
glycemia, non esterified fatty acids (NEFA) by using commercial kits. The isolated
adipocytes were prepared from epididymal fat pads and lipolysis (by measurement of
glycerol release) and lipogenesis (by estimation of labeled glucose incorporation into
lipids) were determined.
Results. The administration of A-4166 results in increased serum insulin and
decreased serum glucose level in all rats irrespective of the diet. A significant
diminution of serum NEFA levels was observed in A-4166 administered Wistar and HTG rats
fed high fat diet. In both groups of rats fed basal diet the lipolysis was not affected by
A-4166. However, a decrease of lipolysis was found after A-4166 in Wistar rats fed
high fat diet. The stimulation of lipolysis by norepinephrine was not influenced by
A-4166. A lowered basal lipolysis was found in HTG rats fed high fat diet. The
stimulation of lipolysis by norepinephrine was diminished in HTG rats as compared to
Wistar animals. Administration of A-4166 did not affect the stimulation of lipolysis by
norepinephrine in HTG rats. A decrease of stimulatory action of insulin on
lipogenesis was found in Wistar rats fed high fat diet and in all groups of HTG rats. The
administration of A-4166 did not change the basal lipogenesis and also the effect of
insulin on lipogenesis.
Conclusions. Besides the hyperinsulinemic and hypoglycemic effect of A-4166 also an
influence on nonesterified fatty acid serum levels was observed in rats fed high fat diet.
This can be partially explained by an antilipolytic action of hyperinsulinemia after
A-4166. The studies of lipogenesis showed that Wistar rats fed high fat diet and HTG
animals are resistant to the stimulatory action of insulin on lipogenesis and that
administration of A-4166 did not affect this response to insulin.
Endocrine Regulations, Vol. 34, 119126, 2000
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A. Goraca
Department of Physiology, Institute of Physiology and Biochemistry, Medical University
of Lodz, 90-131 Lodz, Poland
E-mail:ajanecka@psk2.am.lodz.pl
Objective. It was previously observed that infusion of angiotensin II, hypertonic
saline and N-methyl-D-aspartic acid (NMDA) causes an increase in vasopressin and
cardiodepressant factor release from the posterior pituitary lobe into the blood (Goraca
1998). The aim of present study was to investigate if the cardiodepressant factor and
vasopressin are simultaneously released from the pituitary into the blood dialysate during
acute hypoxia.
Methods. The samples of dialysates of venous blood outflowing from the vicinity of
cavernous sinus of the sella turcica were collected in anaesthetized rats. 30-min hypoxia
was obtained by increasing the respiratory dead space. The concentration of vasopressin in
blood dialysate was determined by radioimmmunoassay, and cardiodepressant activity on
spontaneously discharging pacemaker tissue of the right auricle of the right heart atrium.
Results. Acute hypoxia caused simultaneously an increase in cardiodepressant
activity and vasopressin concentration in the blood dialysate outflowing from the vicinity
of cavernous sinus of the sella turcica.
Conclusions. These data suggest that cardiodepressant factor released together with
vasopressin from the posterior pituitary lobe decrease the heart contraction rate and
improves coronary circulation affected by vasopressin release.
Key words: Posterior pitutary Hypoxia Vasopressin Cardiodepressant
activity
Endocrine Regulations, Vol. 34, 127134, 2000
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A. Russinova, N.Atanassova, L.Kancheva
Institute of Experimental Morphology and Anthropology, Bulgarian Academy of Sciences,
Sofia 1113, Bulgaria
E-mail: valkova@bio25.bas.bg
Objective. To characterize immunocytochemically the antigens recognized by
monoclonal antibodies (Mabs) in the library we have accumulated and to reveal their
spatiotemporal distribution in testicular tissue in the course of testis development.
Methods. Female BALB/c 2-month-old mice were immunized intraperitoneally with
isolated immature Sertoli and germ cells obtained from 20 day old male Wistar rats. The
obtained Mabs were characterized by its cell type-specific binding reaction using light
immunocytochemistry (avidin-biotin-peroxidase complex technique, immunogold-silver
staining, indirect immunofluorescence).
Results. On the basis of immunocystochemical results the selected Mabs were divided
into four classes: 1. Mabs of class 1 recognized the differentiation specific antigens
appearing during germ cell development, two of them revealing a stage-specific expression
of nuclear antigens from preleptotene to early pachytene stage. Other Mabs of this class 1
detected the antigens in pachytene spermatocytes and acrosomes of round spermatids until
their elongation; 2. the labeling of class 2 Mab was restricted only to Sertoli cell
cytoplasm; 3. the binding of class 3 Mabs was observed in the cytoplasm of germ and
Sertoli cells; 4. Mabs of class 4 reacted with antigens distributed in the cytoplasm of
primary spermatocytes, Sertoli and Leydig cells.
Conclusions. The Mabs from the library we have accumulated recognized the antigens
in different cell types at various stages of testicular development and could be an useful
tool for the characterization of cell- and development- specific molecules which may
participate in germ cell differentiation and/or cell to cell interactions during testis
development.
Key words: Immunocytochemistry Testicular antigens Monoclonal antibodies
Endocrine Regulations, Vol. 34, 135143, 2000
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P. Langer, E. Martino, L. Ksinantova, L. Glasso, M. Vigas
Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava,
Slovakia;
Istituto di Endocrinologia, Universita di Pisa, Tirrenia-Pisa, Italia
E-mail: ueenlang@savba.savba.sk
Objective. To compare the changes of TSH level in serum during oral glucose
tolerance test (OGTT) with those resulting from a plain circadian rhythm and, in
addition, to compare such changes between the morning and evevning hours.
Methods. Oral glucose tolerance tests were performed in groups of 8-20 adults after
the oral administration of glucose (75 g in 400 ml tap water) at 8.00, 10.00 and
20.00 h. Blood samples for the estimation of TSH (superensitive IRMA method) were taken in
30 min intervals for following 3 hours. In the same groups of subjects the blood samples
were obtained between 8.00 and 13.00 h or between 20.00 and 23.00 h one week
later for the assessment of plain circadian rhytm of TSH levels.
Results. The level of TSH in a group subjected to OGTT at 8.00 h was
significantly decreased (P<0.05) between 8.30 and 10.30 h, i.e. 30-150 min after
glucose administration which was parallel to the circadian decrease found in the same
subjects. However, this was followed by an increase of TSH up to the original level
reached at 11.00 h which was contrasting to a circadian decrease. Similar
pattern was found also when OGTT was started at 10.00 h. In a group subjected to the
evening OGTT at 20.00 h similar decrease of TSH level was found at 21.00 h which
was contrasting to the circadian increase. However, this was followed by a remarkable
increase of TSH level between 21.00 and 23.00 h which was parallel to the circadian
trend, but much more abrupt than that found without the previous administration of
glucose.
Conclusions. In both the morning and evening OGTT a decrease of TSH level was
found between 30 and 90 min after glucose administration which was followed by an increase
between 90 and 180 min after that. The decrease during the morning test was parallel to
the circadian trend, while the increase was opposite to that. However, an inverse figure
was found in the evening test, the decrease of TSH being opposite and following increase
being parallel to the circadian trend.
Key words: Glucose tolerance test Serum TSH Circadian rhythm
Endocrine Regulations, Vol. 34, 145150, 2000
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E.L. Gregoraszczuk
Laboratory of Reproductive Physiology and Toxicology, Department of Animal Physiology,
Institute of Zoology, Jagiellonian University, Krakσw, Poland
E-mail: greg@zuk.iz.uj.udu.pl
Objective. To examine whether the action of triiodothyronine on aromatase activity
in porcine follicular cells is related to the modulation of estradiol receptor.
Methods. Medium and large preovulatory follicles were incubated in Parker medium
(M199) supplemented with 5 % of calf serum as a control medium or with addition of
triiodothyronine (T3; 10 -9 M), tamoxifen (TMX; 0.1 mM ) or T3+TMX.
The media were collected after 48 h, and assayed for progesterone (P4) and estradiol (E2)
secretion by RIA.
Results. T3 added to the medium decreased E2 secretion by both medium
and large preovulatory follicles (119.7 % and 123.8 %, respectively; P<0.05). In
contrast, T3 increased the secretion of P4 by medium (136 %; P<0.05), while
decreased the P4 secretion by large preovulatory follicles (123 %; P<0.05). The effect
of TMX added alone was also dependent on follicular development. Estradiol secretion by
medium follicles was 2.5 fold higher (p<0.01) than in control and 2.9 fold higher
(P<0.01) than in T3 treated cells. In preovulatory follicles basal E2
secretion was not affected by TMX, while 1.2 fold higher (P<0.05) secretion compared to
T3 treated cells was noted. On the other hand, TMX suppressed basal P4
secretion in medium and preovulatory follicles 1.5 fold (P<0.01) and 1.3 fold
(P<0.05), respectively. The same phenomenon was observed in T3 treated
cells. TMX added to the culture media decreased P4 secretion by medium follicles 1.8 fold
(P<0.01) and that by preovulatory follicles 1.3 fold (P<0.05).
Conclusions. The reversed T3 action on estradiol secretion by both
medium (P<0.05) and large preovulatory (P<0.01) follicles in TMX treated follicles
suggests the up-regulation of ER by triidothyronine.
Key words: Triiodothyronine- Follicular cells- Steroid secretion Estradiol
receptors Estradiol Progesterone
Endocrine Regulations, Vol. 34, 151155, 2000
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R. Denkova, V. Bourneva, K. Baleva, E. Yaneva, B. Nikolov, I. Christov, I. Ivanov.
Institute of Experimental Morphology and Anthropology, Bulgarian Academy of Sciences,
1113 Sofia, Bulgaria
E-mail: timanova@bas.bg
Objective. To investigate the in vitro effect of endothelin-1 (ET-1) on the
steroid production (progesterone [P] and estradiol [E2]) by cultured human granulosa cells
(GCs) during aging.
Material and methods. Human ovarian GCs and granulosa-luteal cells (GLCs) were
isolated from ovaries of female patients (young and premenopausal) undergoing surgery for
non-ovarian benign gynecological conditions. Cells were cultured with ET-1 in the presence
or in the absence of FSH. The concentrations of P and E2 in conditioned media were
determined by means of RIA.
Results. In human GCs and GLCs obtained from young and premenopausal women, ET-1 in
vitro can significantly reduce the FSH stimulated biosynthesis of P, whereas the basal
P biosynthesis is only insignificantly diminished. The in vitro application of
ET-1 have only a sparse inhibitory effect on both the basal and FSH stimulated
biosynthesis of E2 in GCs from the two patient groups.
Conclusions. Our findings support the opinion that ET-1 is a local regulator
of ovarian steroidogenesis which might modulate the steroid production and the stimulatory
effect of FSH in cultured GCs and GLCs obtained from women at various ages.
Key words: Human ovarian steroidogenesis Granulosa cells Granulosa-luteal
cells Endothelin-1 FSH Tissue culture
Endocrine Regulations, Vol. 34, 157160, 2000
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R. Hampl, L. Starka
Institute of Endocrinology, 116 94 Praha 1, Czech Republic
E-mail: rhampl@endo.cz
16alpha-Hydroxydehydroepiandrosterone is the precursor of fetal 16alpha-hydroxylated
estrogens, the main phenolic steroids in pregnancy. For years their serum levels have been
used as biochemical markers of well being of the fetus. In adults, however, increased
levels of 16-hydroxylated estrogens were put in relation to the risk of cancer and, more
recently, to some systemic autoimmune diseases. With respect to immunomodulatory effect of
dehydroepiandrosterone and its metabolites, of which 7-hydroxysteroids formed by
a concurrent reaction to 16-hydroxylation, are believed to be even the more
immunoprotective species, it may be of interest, what is the true role of
16alpha-hydroxydehydroepiandrosterone and other 16-hydroxysteroids of 3beta-hydroxy-5-ene
series. The present knowledge on the latter metabolite was summarized and discussed.
Key words: 16alpha-Hydroxydehydroepiandrosterone 16-Hydroxyestrogens Cancer
Autoim-mune diseases
Endocrine Regulations, Vol. 34, 161165, 2000
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T. Trnovec, A. Kocan, P. Langer, E. Sovcikova, M. Tajtakova, A. Bergman, M. van den Berg, A. Brouwer, M. Machala, G. Winneke, B. Sampson, B. Brunekreef, M. Pavuk, V. Bencko
Institute of Preventive and Clinical Medicine, Bratislava, Slovakia;
Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia;
1st Clinic of Internal Medicine, P.J. Safarik University, Kosice, Slovakia;
Department of Environmental Chemistry, Stockholm University, Stockholm, Sweden;
Research Institute of Toxicology, Utrecht University, Utrecht, Netherlands;
Research Institute of Veterinary Medicine, Brno, Czech Republic;
Medical Institute of Environmental Hygiene, Duesseldorf, Germany;
Charring Cross Hospital, London, U.K.;
Institute of Hygiene and Epidemiology, 1st Faculty of Medicine, Charles University,
Prague, Czech Republic
ENDOCRINE REGULATIONS, Vol. 34, 167-168, 2000
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