Electronic Library of Scientific Literature - © Academic Electronic Press


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.
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


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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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