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Volume 36 / No. 1 / 2002
Ken Walder, Nick Oakes, Richard P.Fahey, Greg Cooney, Paul Z. Zimmet, Greg R. Collier
Metabolic Research Unit, School of Health Sciences, Deakin University, Waurn
Ponds 3217, Victoria, Australia;
Cardiovascular Pharmacology, AstraZeneca R&D Mölndal, S-431 83 Mölndal,
Sweden;
Garvan Institute of Medical Research, Darlinghurst 2010, NSW, Australia;
International Diabetes Institute, Caulfield 3162, Victoria, Australia
E-mail: walder@deakin.edu.au
Objective. To investigate lipid profiles in Psammomys obesus and
relationships between lipid profile and other components of the Metabolic
Syndrome.
Methods. A total number of 49 adults with a wide range of body
weight and glucose tolerance were studied in a cross-sectional analysis.
Plasma cholesterol distribution profiles were measured by size exclusion lipid
chromatography. Blood glucose was measured using an enzymatic glucose analyser,
and plasma insulin was determined by radioimmunossay.
Results. Obese diabetic Psammomys obesus had elevated plasma
cholesterol (P=0.003) and triglyceride levels (p>0.001) compared to their
lean littermates. The hypercholesterolemia was mainly due to increased
circulating levels of VLDL-cholesterol (P=0.003) and LDL-cholesterol (P=0.003)
in these animals. Multiple linear regression analyses revealed that body weight
was independently associated with plasma cholesterol (P=0.011) and LDL
concentration (P=0.009), while plasma insulin was associated with
VLDL-cholesterol concentration (P=0.005). All of the variables measured
exhibited continuous distributions across a wide range of phenotypes, from
a normal rodent lipid profile to profound dyslipidemia.
Conclusions. These data suggest that the dyslipidemia in obese, diabetic Psammomys
obesus is closely associated with other components of the Metabolic
Syndrome, including obesity and insulin resistance.
Keywords: Dyslipidemia – Psammomys obesus – Metabolic
syndrome
ENDOCRINE REGULATIONS, Vol. 36, 1-8, 2002
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Z. Ostrowska, B. Kos-Kudla, B. Marek, D. Kajdaniuk, N. Ciesielska-Kopacz
Department of Clinical Biochemistry,
Department of Pathophysiology and Endocrinology,
Department of Internal Diseases, Allergology and Clinical Immunology, Silesian
Medical Academy, Zabrze, Poland
E-mail: ozdrasiek@poczta.onet.pl
Objective. To assess the relationship between the dynamic pattern of
IGF-I levels and chosen biochemical markers of bone metabolism in ovariectomized
rats – a model of postmenopausal osteoporosis.
Methods. Six-month-old rats were randomized to sham operation (control
group) or ovariectomy. Serum levels of insulin-like growth factor (IGF-I) and
chosen biochemical markers of bone metabolism (alkaline phosphatase – ALP,
carboxyterminal propeptide of type I procollagen – PICP, cross-linked
carboxyterminal telopeptide of type I collagen – ICTP in serum as well as
urinary excretion of hydroxyproline – HYP and total calcium – Ca) were
measured before (group 0) and 1, 2, 3, 4, 6, 8, 12, 16, 20, 24 and 28 weeks
after the operation.
Results. In a model of experimental osteoporosis induced by ovariectomy
in female rats a distinct tendency to decrease the IGF-I concentrations was
shown. Differences were significant in relation to the control group in a period
from 2 to 28 weeks after operation. Ovariectomy stimulated the values of studied
markers of bone metabolism; it was more intensified in regard to resorption
markers. Significant ICTP and HYP concentrations’ changes, in relation to the
control group, were shown in the some period and total calcium – from 2 to 16
weeks after ovariectomy. However, the values of studied markers of bone
formation were generally changing to a slight degree. Significant differences of
ALP activity, in relation to the control group, were observed only at 8 and 20
weeks, while those of PICP concentrations were found at in 4, 8 and 12 weeks
after the operation. The alterations in the levels of IGF-I correlated
significantly and negatively with the changes in ALP activity as well as in
PICP, ICTP, HYP and Ca concentrations both in ovariectomized and control rats.
This relation was more xpressed in the ovariectomized group.
Conclusions. Our findings suggest that secondary changes in IGF-I
concentration, due to the deficiency of sex hormones, results in altered bone
metabolism in ovariectomized rats.
Key words: IGF-I – Bone metabolism – Model of postmenopausal
osteoporosis – Female rats
ENDOCRINE REGULATIONS, Vol. 36, 9-17, 2002
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R.Denkova, V. Bourneva, E. Yaneva, K. Baleva, B. Nikolov, I. Ivanov, K. Simeonov, T Timeva
Institute of Experimental Morphology and Anthropology and
Institute of Experimental Pathology and Parasitology, Bulgarian Academy of
Sciences, 1113 Sofia, Bulgaria,
University Hospital ”Maychin dom”, Sofia, Bulgaria
E-mail: rdenkova@hotmail.com
Objective. Nitric oxide (NO) is involved in different cell functions
including ovarian steroid production. Endothelin-1 (ET-1) was found to regulate
the steroidogenesis in ovarian granulosa cells (GC). The present study was
designed to receive more information about the mechanism of action of NO in the
process of ET-1 induced progesterone (P) inhibition, using nicotine amide
dinucleotide phosphate-diaphorase (NADPH-d) histochemistry as a cofactor of
oxidoreductase enzymes (e. g. nitric oxide).
Methods. Granulosa cells were isolated from ovaries of: 1. young women
with natural cycle or after in vitro fertilization (IVF), 2. premenopausal
women. The obtained cells were cultured with endothelin-1 and the concentration
of progesterone in conditioned media was determined by RIA. For the estimation
of NADPH-d the histochemical reaction was used.
Results. The suppressive effect of ET-1 on P production in granulosa
cells was more pronounced in young women with natural cycles, slightly weaker
after IVF and the most ineffective in premenopausal patients. The number of
NADPH-d positive GCs was higher in young non hormonally stimulated women,
slightly lower after IVF and small in premenopausal ones.
Conclusions. The results indicate the possible role of NADPH-d or NOS in
the mechanism of ET-1 provoked P suppression.
Key words: Human granulosa cells – Progesterone – Endothelin-1
– NADPH-diaphorase
ENDOCRINE REGULATIONS, Vol 36, 19-22, 2002
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Zdeno Pirnik, Alexander Kiss
Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska
3, 833 06 Bratislava, Slovakia
E-mail:ueenpirn@ savba.sk
Objective. The aim of the present experiments was to elucidate: 1. the
stability and usefulness of a 3,3´-diaminobenzidine tetrahydrochloride
(DAB) chromogen intensified with nickel and cobalt (DAB-Ni-Co) in the
dual immunocytochemical and in situ hybridization procedure using
Fos-protein antibody and oxytocin mRNA (OXY mRNA) radiolabeled probe; 2. the
susceptibility of the free floating and mounted cryostat sections,
freshly prepared or stored for 24 month at –20 °C.
Methods. The dual staining procedure was tested on neurons of the
hypothalamic paraventricular nucleus (PVN) activated by an intraperitoneal
injection of hypertonic saline (HS, 1.5 M, 5 ml, 60 min). Two dual labeling
procedures were compared: 1/ Fos-immunostaining with DAB alone and combined with
OXY mRNA in situ hybridization and 2/ Fos-immunostaining with DAB-Ni-Co
and combined with OXY mRNA in situ hybridization. In both experiments
free floating and mounted cryostat sections, freshly prepared or stored for 24
month at –20 °C, were tested.
Results. HS strongly stimulated both the parvicellular and magnocellular
population of PVN neurons followed by an extensive Fos-immunolabeling in many
cell nuclei. The first staining sequence with Fos-DAB labeling resulted in a good
staining quality on both the fresh and for 24 month stored mounted sections.
Although the free floating sections during the in situ procedure showed
the same staining properties as the mounted ones, with respect to their
increased fragility on the end of the hybridization procedure, they were
difficult to mount and stretch on poly-L-lysine coated slides. On the other
hand, Fos-immunolabeling with DAB-Ni-Co exhibited improved staining density of
the single DAB chromogen in the first staining sequence of the dual staining
procedure. However, DAB-Ni-Co mixture showed up as an unstable chromogen complex
which after completing the in situ hybridization process completely
disappeared from each type of section.
Conclusions. The results of the present dual immunocytochemical-in
situ hybridization staining utilizing Fos-antibody and OXY mRNA oligoprobe
indicate that this procedure is applicable on free floating as well as
mounted cryostat sections, freshly prepared or stored for 24 month at –20 °C.
However, the dual procedure is only successful when the immunoproduct in the
first sequence is visualized with an unintensified DAB and not with combined
DAB-Ni-Co chromogen and when the histological sections in the second sequence
are not processed as free floating but are attached to a poly-L-lysine
coated microscopic glasses.
Key words: Fos immunohistochemistry – DAB and DAB-Ni-Co stainings
- OXY mRNA in situ hybridization – Dual immunocytochemistry - in
situ hybridization histochemistry - Rat
ENDOCRINE REGULATIONS, Vol. 36, 23-30, 2002
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M. Dvorcakova, D. Macejova, V. Pallet, P. Higueret, M-P. Vasson, E. Rock, J. Brtko
Institute of Experimental Endocrinology, SAS, Bratislava, Slovak Republic;
Laboratory of Nutrition, University of Bordeaux I, Talence, France;
Laboratory of Biochemistry, Molecular Biology and Nutrition, Faculty of
Pharmacy, Clermont-Ferrand, France;
INRA, UMMM, CRNH, Centre de Theix, France
E-mail: ueenbrtk@savba.savba.sk
Transglutaminases catalyze the posttranslation modification of proteins by
catalyzing Ca2+ dependent acyl-transfer reaction resulting in the
formation of new g-amide bonds between g-carboxamide groups of peptide-bound
glutamine residues and various primary amines. Such glutamine residue serves as
acyl-donor and the most common acyl-acceptors are e-amino groups of
peptide–bound lysine residues or primary amino groups of some naturally
occurring polyamines, like putrescine or spermidine. The active site of cysteine
reacts first with the g-carboxamide group of glutamine residue to form the
acyl-enzyme intermediate under the release of ammonia. In the second step, the
complex reacts with a primary amine to form an isopeptide bond and liberate the
reactivated enzyme.
The presence of transglutaminases has been observed in various endocrine glands
such as human pituitary which was investigated by immunohistochemical methods
using specific antibodies. A significant increase in the expression and activity
of tissues transglutaminase was observed during involution of thymus. In the
genital tract of the male rat two different forms of the enzyme transglutaminase
could be identified and characterized. the presence of p53 and tissues
transglutaminase gene expressions in human normal and pathologic adrenal
tissues. The Ca2+-responsive enzyme transglutaminase, which catalyzes
the cross-bridging of proteins, was found in pancreatic islet cells.
ENDOCRINE REGULATIONS, Vol. 36, 31-36, 2002
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Silvia Kucharova, Robert Farkas
Institute of Experimental Endocrinology, Slovak Academy of Sciences, 833 06
Bratislava, Slovakia
E-mail: ueenfark@ savba.savba.sk
Programmed cell death (PCD) represents a highly efficient and very sophisticated system for removing cells from the surrounding environment. As deadly as it may be, PCD is essential for elimination of aberrant cells and the survival of the living organism as a whole. Therefore, PCD is meticulously controlled, and among major regulatory actors belong small lipophilic hormones acting as ligands of the members of a nuclear receptor superfamily. In general, these hormones which include steroids, thyroids, retinoids, vitamin D3 derivatives, serve a critical role in the maintenance of homeostasis. For example, steroids regulate metabolism, reproduction, and development in animals that are as different as insects and humans. During animal development, steroids trigger distinct responses including cell differentiation and programmed cell death. Thus, hormones have been linked to numerous human health problems, and defects in hormone triggered programmed cell death may result e.g. in the survival of tumor cells or degenerative disorders. In vertebrate and invertebrate organisms where steroids including androgens, estrogens, progesterone, glucocorticoids and ecdysteroids regulate cell death, intensive study of this processes has resulted in a wealth of new information regarding how small lipophilic hormones contribute to cell demise within an organism. There is a great knowledge on the execution phase of apoptosis, the most frequent form of programmed cell death, and on the variety of its inducers. Even though we will review also recent advances on the topics various small ligands in the role of inducers, nevertheless we want to highlight the mechanisms that links action of hormones to the activation of apoptotic execution, the complex of processes which are poorly understood so far.
ENDOCRINE REGULATIONS, Vol. 36, 37-60, 2002
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