Estradiol and calcium affect the growth hormone producing cells in female middle-aged rats

The effects of multiple doses of estradiol dipropionate (EDP) or calcium glucoheptonate (Ca) on the growth and function of pituitary somatotropes (GH cells) were studied. Female middle-aged rats were receiving i.p. EDP (0.625 mg i.p./kg b.w), or Ca (11.4 mg/kg b.w) every day for two weeks. Blood samples were collected for hormone analyses and pituitaries dissected for histological and morphometric evaluation 24 h after the last injection. GH-producing cells were examined using the peroxidase-antiperoxidase (PAP) immuno-histochemical procedure. Both EDP- and Ca-treatment significantly decreased all morphometric parameters of GH cells (p<0.05) in comparison with the corresponding controls. Serum concentration of growth hormone (GH) in EDP- or Ca-treated groups was lower by 65% and 13% (p<0.05) respectively comparing to the controls. The difference between all morphometric parameters of EDP- and Ca-treated rats was statistically significant (p<0.05) in relation to the controls. These findings suggest that multiple EDP, or Ca application affects (directly or indirectly) the control of growth and secretory activity of GH cells in middle-aged female rats.Ispitivani su efekti višekratnih doza estradiol dipropionata (EDP) ili kalcijum glukoheptonata (Ca) na rast i funkciju hipofiznih ćelija hormona rasta (GH) acikličnih ženki Wistar pacova. Aciklične ženke su svakodnevno tokom dve nedelje i.p. dobijale 0.625 mg EDP/kg t.m., ili 11.4 mg Ca/kg t.m.. Krv je sakuplja na radi određivanja koncentracije hormona rasta u serumu, a hipofize su pripremane za histološku i morfometrijsku analizu. GH ćelije su imunocitohemijski obeležavane metodom peroksidaza-antiperoksidaza (PAP). Morfometrijski para-metri su bili značajno smanjeni (p<0.05) u životinja tretiranih EDP-om, ili kalcijumom u poređenju sa odgovarajućim kontrolama. Koncentracija hormona rasta u serumu bila je takođe značajno niža (p<0.05) u obe tretirane grupe (za 65% odnosno za 13%) u poređenju sa odgovarajućom kontrolom. Dobijeni rezultati ukazuju da višekratni tretman acikličnih ženki pacova EDP-om ili Ca-glukoheptonatom deluje inhibitorno na GH ćelije i da su i estrogenui i kalcijum uključeni na specifičan način u rast i sekretornu aktivnost GH ćelija hipofize.Projekat ministarstva br. 171

Calcium administration decreases thyroid functioning in middle-aged female rats

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The effects of estradiol and human chorionic gonadotropin on acth cells in peripubertal female rats: A histological and stereological study

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

Thyroid Mediation of the Isoflavone Effects on Osteoporotic Bone: The Endocrine Interference With a Beneficial Outcome

In this opinion article, we intend to elaborate on thyroid mediation of isoflavone effects mainly on the bone of aging males, which appears to have an important role but is still insufficiently analyzed in the existing literature. Namely, the consequences of exposure to endocrine-disrupting chemicals strongly depend on the timing of interaction and life stages of humans and animals, so we intended to highlight the thyroid-related mechanism underlying the beneficial effect of isoflavones on aged male bone

Old age-associated impairment of the rat liver antioxidant defense system: the basis for affirmation of the experimental model

Letter to the Edito

Vitex agnus-castus L.: Essential oil increases human erythrocyte membrane fluidity

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 Resonance 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.Fluidnost membrane eritrocita uslovljava njihove reološke karakteristike, svojevrsne dinamičke kvalitete, izmenjene u hipertenziji i aterosklerozi. Rizik od navedenih i drugih kardiovaskularnih oboljenja se kod žena povećava sa starenjem. Tegobe koje prate menopauzu se obično ublažavaju supstitucionom hormonskom terapijom, koja može povećati rizik od pojave malignih oboljenja. Esencijalno ulje biljke Vitex agnus-castus L. sadrži različita organska jedinjenja (monoterpene, seskviterpene i terpenoide) i sve češće se koristi kao alternativno terapijsko sredstvo za simptome menopauze. Navedene komponente esencijalnog ulja mogu se ugraditi u ćelijske 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. Korišćena je spektroskopija elektronske paramagnetne rezonance i masnokiselinske spinske probe (5-doksil stearinska i 12-doksil stearinska kiselina), čiji spektri za vise od fluidnosti membrane. Nakon tretmana eritrocita esencijalnim uljem biljke Vitex agnus-castus utvrđeno je značajno (p=0,029) i reverzibilno povećanje fluidnosti njihove membrane u dubljim, hidrofobnim regionima, dok u površinskim, hidrofilnim regionima eritrocitne membrane nisu utvrđene značajne promene (p>0,05). Ovi rezultati ukazuju na povećanje fluidnosti eritrocitne membrane nakon tretmana esencijalnim uljem biljke Vitex agnus-castus, što može biti koristan efekat pri tretmanu pacijentkinja sa hipertenzijom i drugim kardiovaskularnim oboljenjima u menopauzi.Projekat ministarstva br. 173009 i br. 17301

Estradiol and GH cells: Immunohistomorphometric study in an animal model of andropause

Andropause, the culminating phase of ageing in males is characterized by the decline of the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis that is responsible for somatic development. Estrogens on the other hand, assume a relevant somatic role, as well as the one in the pituitary. They are particularly interesting because of their therapeutic uses in certain common ageing-associated diseases. The aim of the present study was to examine the effects of subcutaneous treatment with estradiol, dipropionate on the immunohistomorphometric features of GH cells, in an animal model of the andropause. Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and estradiol dipropionate-treated orchidectomized (Orx+Edp) groups. Estradiol dipropionate (0.625 mg/kg/day) was administered subcutaneously for three weeks while the SO and Orx groups received the vehicle alone. GH cells were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure. In the Orx+Edp group, GH cell volumes as well as the relative volume densities were significantly (p<0.05) decreased, by 27.4% and by 61.1%, respectively, in comparison with the same parameters of SO animals. Compared to the Orx animals, the cell volumes and relative volume densities of GH cells in Orx+Edp group were also significantly (p<0.05) decreased, by 23.2% and by 64.1%, respectively. It can be concluded that chronic estradiol dipropionate application in an animal in the andropause results in the suppression of immunohistochemical and morphometric parameters of pituitary GH cells.Projekat ministarstva br.17300

Estradiol and calcium affect the growth hormone producing cells in female middle-aged rats

The effects of multiple doses of estradiol dipropionate (EDP) or calcium glucoheptonate (Ca) on the growth and function of pituitary somatotropes (GH cells) were studied. Female middle-aged rats were receiving i.p. EDP (0.625 mg i.p./kg b.w), or Ca (11.4 mg/kg b.w) every day for two weeks. Blood samples were collected for hormone analyses and pituitaries dissected for histological and morphometric evaluation 24 h after the last injection. GH-producing cells were examined using the peroxidase-antiperoxidase (PAP) immuno-histochemical procedure. Both EDP- and Ca-treatment significantly decreased all morphometric parameters of GH cells (p<0.05) in comparison with the corresponding controls. Serum concentration of growth hormone (GH) in EDP- or Ca-treated groups was lower by 65% and 13% (p<0.05) respectively comparing to the controls. The difference between all morphometric parameters of EDP- and Ca-treated rats was statistically significant (p<0.05) in relation to the controls. These findings suggest that multiple EDP, or Ca application affects (directly or indirectly) the control of growth and secretory activity of GH cells in middle-aged female rats.Ispitivani su efekti višekratnih doza estradiol dipropionata (EDP) ili kalcijum glukoheptonata (Ca) na rast i funkciju hipofiznih ćelija hormona rasta (GH) acikličnih ženki Wistar pacova. Aciklične ženke su svakodnevno tokom dve nedelje i.p. dobijale 0.625 mg EDP/kg t.m., ili 11.4 mg Ca/kg t.m.. Krv je sakuplja na radi određivanja koncentracije hormona rasta u serumu, a hipofize su pripremane za histološku i morfometrijsku analizu. GH ćelije su imunocitohemijski obeležavane metodom peroksidaza-antiperoksidaza (PAP). Morfometrijski para-metri su bili značajno smanjeni (p<0.05) u životinja tretiranih EDP-om, ili kalcijumom u poređenju sa odgovarajućim kontrolama. Koncentracija hormona rasta u serumu bila je takođe značajno niža (p<0.05) u obe tretirane grupe (za 65% odnosno za 13%) u poređenju sa odgovarajućom kontrolom. Dobijeni rezultati ukazuju da višekratni tretman acikličnih ženki pacova EDP-om ili Ca-glukoheptonatom deluje inhibitorno na GH ćelije i da su i estrogenui i kalcijum uključeni na specifičan način u rast i sekretornu aktivnost GH ćelija hipofize.Projekat ministarstva br. 171

Pituitary Hyperplasia, Hormonal Changes and Prolactinoma Development in Males Exposed to Estrogens — An Insight From Translational Studies

Estrogen signaling plays an important role in pituitary development and function. In sensitive rat or mice strains of both sexes, estrogen treatments promote lactotropic cell proliferation and induce the formation of pituitary adenomas (dominantly prolactin or growth-hormone-secreting ones). In male patients receiving estrogen, treatment does not necessarily result in pituitary hyperplasia, hyperprolactinemia or adenoma development. In this review, we comprehensively analyze the mechanisms of estrogen action upon their application in male animal models comparing it with available data in human subjects. Sex-specific molecular targets of estrogen action in lactotropic (PRL) cells are highlighted in the context of their proliferative and secretory activity. In addition, putative effects of estradiol on the cellular/tumor microenvironment and the contribution of postnatal pituitary progenitor/stem cells and transdifferentiation processes to prolactinoma development have been analyzed. Finally, estrogen-induced morphological and hormone-secreting changes in pituitary thyrotropic (TSH) and adrenocorticotropic (ACTH) cells are discussed, as well as the putative role of the thyroid and/or glucocorticoid hormones in prolactinoma development, based on the current scarce literature

The effect of ovariectomy on thyroid c cells of adult rats

The structure and function of C cells of adult female rats after ovariectomy (Ovx) were investigated. Intact control and Ovx rats were i.p. treated with sterile olive oil for 4 weeks. Peroxidase-antiperoxidase (PAP) immunohistochemical procedure was applied to localize calcitonin (CT) in thyroid C cells while its serum content was determined by RIA method. Morphometric analyses of the C cells volume, that of their nuclei and relative volume density included stereological method with the multipurpose test system M42. Also, the average number of C cells number per mm2 was calculated. Ovx led to a significant increase in body weight (21%; p<0.005). At the same time the C cells of Ovx rats had a significantly decreased cell volume (13%; p<0.005) and their number per mm2 was increased by 59% (p<0.001) in comparison with the controls. Ovx resulted in reduction of serum CT level by 45% comparing to the corresponding controls. Based on these data it can be concluded that Ovx inhibits both the structure and function of the C cells.U ovom radu ispitivana je struktura i funkcija C ćelija adultnih ženki pacova posle ovarijektomije (Ovx). Intaktne kontrolne i Ovx životinje su tretirane i.p. sterilnim maslinovim uljem u trajanju od četiri nedelje. Za lokalizaciju kalcitonina (CT) u C ćelijama štitaste žlezde korišćena je imunohistohemijska metoda peroksidaze- antiperoksidaze (PAP). Nivo CT-a u serumu određen je RIA metodom. Morfometrijska ispitivanja volumena C ćelija, njihovih jedara i relativne volumenske gustine ćelija vršena su višenamenskim testnim sistemom M42. Takođe je izračunat broj C ćelija po mm2. Statistička obrada podataka vršena je Studentovim t-testom. Posle Ovx-a telesna masa životinja značajno je povećana za 21% (p<0.005). Volumen C ćelija Ovx pacova značajno je smanjen za 13% (p<0.005), njihov broj po mm2 povećan za 59% (p<0.001), a nivo CT-a u serumu smanjen za 45% u poređenju sa intaktnom kontrolom. Na osnovu dobijenih rezultata možemo zaključiti da Ovx deluje inhibitorno na strukturu i funkciju C ćelija štitaste žlezde kod pacova