Androgen deficiency is one of the major factors leading to the development of osteoporosis in men. Since calcitonin (CT) is a potent antiresorptive agent, in the present study we investigated the effects of androgen deficiency and subsequent testosterone and estradiol treatment on CT-producing thyroid C cells, skeletal and hormonal changes in middle-aged orchidectomized (Orx) rats. Fifteen-month-old male Wistar rats were either Orx or sham-operated (SO). One group of Orx rats received 5 mg kg À1 b.w. testosterone propionate (TP) subcutaneously, while another group was injected with 0.06 mg kg À1 b.w. estradiol dipropionate (EDP) once a day for 3 weeks. A peroxidase-antiperoxidase method was applied for localization of CT in the C cells. The studies included ultrastructural microscopic observation of these cells. The metaphyseal region of the proximal tibia was measured histomorphometrically using an IMAGEJ public domain image processing program. TP or EDP treatment significantly increased C cell volume (Vc), volume densities (Vv) and serum CT concentration compared with the Orx animals. Administration of both TP and EDP significantly enhanced cancellous bone area (B.Ar), trabecular thickness (Tb.Th) and trabecular number (Tb.N) and reduced trabecular separation (Tb.Sp). Serum osteocalcin (OC) and urinary Ca concentrations were significantly lower after these treatments in comparison with Orx rats. These data suggest that testosterone and estradiol treatment in Orx middle-aged rats affect calcitonin-producing thyroid C cells, which may contribute to the bone protective effects of sex hormones in the rat model of male osteoporosis.

Soy isoflavones are diphenolic compounds that are frequently used for alternative treatment of ageing symptoms in both genders. They operate at principally two hierarchical levels of functional organization - cellular and molecular, while these 'types' of action appear to have indefinite borders. Soy isoflavone action at the cellular level involves inter alia the effects on cell mechanics. This epigenetic and modular determinant of cell function and fate is defined by: the anchorage to extracellular matrix (ECM) and neighboring cells, cytoskeleton organization, membrane tension and vesicle trafficking. Soy isoflavones have been reported to: (i) generally fashion an inert cell phenotype in some cancers and enhance the cell anchorage in connective tissues, via the effects on ECM proteins, focal adhesion kinases-mediated events and matrix metalloproteinases inhibition; (ii) affect cytoskeleton integrity, the effects being related to Ca(2+) ions fluxes and involving cell retraction or differentiation/proliferation-related variations in mechanical status; (iii) increase, remain "silent" or decrease membrane tension/fluidity, which depends on polarity and a number and arrangement of functional groups in applied isoflavone; (iv) provoke inhibitory effects on vesicle trafficking and exo-/endocytosis, which are usually followed by changed cell morphology. Here we present and discuss the abundance of effects arising from cells' "encounter" with soy isoflavones, focusing on different morphofunctional definers of cell mechanics.

Summary: Erythrocyte membrane fluidity is related to their rheologic behavior, the dynamic quality of erythrocytes, which is tempted in hypertension and atherosclerosis. An increased risk of these and other cardiovascular diseases occurs in ageing women. Menopause-related conditions are often treated with hormone replacement therapy that may increase the risk of malignancies. Vitex agnus-castus L. essential oil contains various organic compounds (monoterpenes, sesquiterpenes and terpenoids), and is increasingly used as an alternative therapy for menopausal symptoms. These components of the oil may be incorporated into cell membranes, thereby changing the membrane fluidity. The aim of this study was to determine the effects of Vitex agnuscastus essential oil on human erythrocyte membrane fluidity at graded depths. We used Electron Paramagnetic Resonan ce spectroscopy and fatty acid spin probes (5-doxyl stearic acid and 12-doxyl stearic acid), whose spectra depend on membrane fluidity. After treatment with Vitex agnus-castus essential oil the erythrocytes had a significant (p=0.029) and reversible increase in membrane fluidity in the deeper hydrophobic membrane regions, with no change (p>0.05) in fluidity near the membrane's hydrophilic surface. These results document increased fluidity of the human erythrocyte membrane by Vitex agnus-castus essential oil, and this action may be useful in patients with menopause--related hypertension and other cardiovascular conditions. Keywords: erythrocytes, membrane fluidity, Vac essential oil, EPR Kratak sadr`aj: Fluidnost membrane eritrocita uslovljava njihove reolo{ke karakteristike, svojevrsne dinami~ke kva litete, izmenjene u hipertenziji i aterosklerozi. Rizik od navedenih i drugih kardiovaskularnih oboljenja se kod `ena po ve}ava sa sta renjem. Tegobe koje prate menopauzu se obi~no ubla`avaju supstitucionom hormonskom terapijom, koja mo`e pove}ati rizik od pojave malignih oboljenja. Esencijalno ulje biljke Vitex agnus-castus L. sadr`i razli~ita organska jedinjenja (monoterpene, seskviterpene i terpenoide) i svẽ e{}e se koristi kao alternativno terapijsko sredstvo za simptome me no pauze. Navedene komponente esencijalnog ulja mogu se ugraditi u }elijske membrane i menjati njihovu fluidnost. Cilj studije bio je da se utvrde efekti esencijalnog ulja biljke Vitex agnus-castus na fluidnost membrane eritrocita po njenoj du bini. Kori{}ena je spektroskopija elektronske paramagnetne rezonance i masnokiselinske spinske probe (5-dok sil stea rinska i 12-doksil stearinska kiselina), ~iji spektri za vise od fluidnosti membrane. Nakon tretmana eritrocita esencijal nim uljem biljke Vitex agnus-castus utvr|eno je zna~ajno (p=0,029) i reverzibilno pove}anje fluidnosti njihove membrane u dubljim, hidrofobnim regionima, dok u povr{inskim, hidrofilnim regionima eritrocitne membrane nisu utvr|ene zna~ajne promene (p>0,05). Ovi rezultati uka zuju na po ve}anje fluidnosti eritrocitne membrane nakon tretmana esencijalnim uljem biljke Vitex agnus-castus, {to mo`e biti ko ristan efekat pri tretm...

Ageing in men is accompanied by an increased occurrence of osteoporosis, but traditional hormonal replacement therapy elevates the risk of developing endocrine cancer. Vitex agnus-castus L. (Vac) essential oil is commonly used as an alternative therapy for ageing symptoms in both men and women. It is known that calcitonin (CT), thyroid C cell hormone, inhibits bone resorption. The purpose of this experimental study was to investigate the influence of Vac essential oil administration on the immunohistomorphometric features of thyroid C cells and bone metabolism in 16-month-old male Wistar rats. The first group of animals (n=8) was treated subcutaneously (s.c.) with 60 mg/kg of Vac essential oil once a day for 3 weeks. Control animals (n=8) received sterile olive oil s.c. by the same schedule. After Vac treatment significant increases (p<0.05) were found in the volume of C cells (by 10%) and serum CT level (by 27%) compared with the controls. Serum osteocalcin (OC) and calcium (Ca2+) levels were 31% and 8% lower (p<0.05) respectively, in comparison with the control group. These are the first experimental results suggesting that Vac essential oil stimulates thyroid C cells activity and decreases bone turnover in middle-aged male rats. [Projekat Ministarstva nauke Republike Srbije, br. 173009

The effects of estradiol (EDP) and human chorionic gonadotropin (HCG) on histological and stereological features of adrenocorticotropic (ACTH) cells in peripubertal female rats were examined. The first group of females received five injections of EDP (0.25 mg/kg b.w.), every second day from the 4th to 14th day after birth, and was killed at the peripubertal stage. The second group of females was given two injections of pregnyl-gonadotrophinum chorionicum (HCG; 50 IU/kg body weight) on the 36th and 37th days after birth, and it was killed 24 h after the last treatment. The controls were injected with an equivalent volume of the corresponding vehicle. ACTH cells were immunohistochemically labeled and stereologically evaluated. Stereological analysis showed that the volume of ACTH cells and their volume density in peripubertal females treated with EDP, were decreased by 15.6% and 53.8% (p<0.05), respectively, compared to the controls. In HCG-treated animals, the observed parameters were increased by 39.2% and 15.4% (p<0.05), respectively, in comparison with the control females. These findings suggest that the application of EDP or HCG exerted opposite effects on the stereological features of pituitary ACTH cells. [Projekat Ministarstva nauke Republike Srbije, br. ON 173009]