Human anterior pituitary's ACTH cells during the aging process: immunohistochemic and morphometric study.

Corticotrophs produce a hormone that stimulates the adrenal gland cortex to secrete glucocorticoids, which in turn have effects on carbohydrate and protein metabolism. Quantification, morphological characteristics, and distribution of corticotrophs in the anterior pituitary and changes in the number and shape of the cells during aging have been examined using immunohistochemical and morphometric methods. The material consisted of 14 anterior pituitaries taken from cadavers at routine autopsy. The tissue was processed by standard histological procedure and the obtained slices were stained by the monoclonal anti-ACTH antibody for corticotrophs identification. Digital images of stained histological sections were analyzed using the morphometric method with the Image J system. The volume density of ACTH positive cells was determined. The cases were classified into three age groups. One-way ANOVA showed that the volume density of the corticotrophs was significantly higher in the second and third group in relation to the first group. The difference in the volume densities of the corticotrophs between the genders was not significant. Morphometric and statistical analyses demonstrated a significant positive correlation between the corticotrophs volume densities and the age of the evaluated cases. Linear regression showed that age significantly predicts corticotrophs volume density. Corticotrophs significantly increase during the life span.

An Extremely Low Frequency Magnetic Field and Global Cerebral Ischemia Affect Pituitary ACTH and TSH Cells in Gerbils.

The neuroendocrine system can be modulated by a magnetic field and cerebral ischemia as external and internal stressors, respectively. This study deals with the separate or combined effects of an extremely low frequency (ELF) magnetic field (50 Hz, average magnetic field of 0.5 mT) for 7 days and global cerebral ischemia for 10 min on the morpho-functional features of pituitary adrenocorticotrophic (ACTH) and thyrotrophic (TSH) cells in 3-month-old gerbils. To determine the immediate and delayed effects of the applied stressors, measurements were made on the 7th and 14th days after the onset of the experiment. The ELF magnetic field and 10-min global cerebral ischemia, separately and particularly in combination, decreased (P < 0.05) the volume density of ACTH cells, while only in combination were intracellular ACTH content and plasma ACTH concentration increased (P < 0.05) on day 7. The ELF magnetic field elevated serum TSH concentration on day 7 and intracellular TSHß content on day 14 (P < 0.05). Also, 10-min global cerebral ischemia alone increased serum TSH concentration (P < 0.05), while in combination with the ELF magnetic field it elevated (P < 0.05) intracellular TSHß content on day 14. In conclusion, an ELF magnetic field and/or 10-min global cerebral ischemia can induce immediate and delayed stimulation of ACTH and TSH synthesis and secretion. Bioelectromagnetics. 2020;41:91-103. © 2019 Bioelectromagnetics Society.

Short- and long-term exposure to alternating magnetic field (50 Hz, 0.5 mT) affects rat pituitary ACTH cells: Stereological study.

The aim of the present study was to determine does extremely low frequency magnetic field (ELF-MF, 50 Hz, 0.5 mT) affect pituitary adrenocorticotroph (ACTH) cells in adult animals. We performed two series of experiments: (1) short-term exposure of 3-month-old rats to ELF-MF for 1 and 7 days, and (2) long-term exposure of rats to ELF-MF from their conception to 3 months of age. Stereological study was performed on immunolabeled pituitary ACTH cells. The total number and volume of ACTH cells, the volume of their nuclei and pituitary volume were measured. ELF-MF exposure for 1 day significantly decreased total number and volume of ACTH cells, the volume of their nuclei, as well as pituitary volume. ELF-MF exposure for 7 days significantly reduced only the volume of ACTH cells. Life-long exposure to ELF-MF induced decrease in the volume of ACTH cells and pituitary volume. We can conclude that the applied ELF-MF has a strong influence on morphometrical parameters of the pituitary ACTH cells and could be considered as a stressogenic factor.

Central ghrelin treatment stimulates ACTH cells in normal-fed, food-restricted and high-fed rats: An immunohistomorphometric and hormonal study.

Changes in feeding regime represent serious stress, while ghrelin is considered a key player in energy balance. We investigated the effects of intracerebroventricular (ICV) ghrelin application on pituitary adrenocorticotropic (ACTH) cells in rats fed diets differing in energy content. Before the ICV treatment, male Wistar rats were subjected to three different feeding regimes for 4 weeks: normal-fed (NF), food-restricted (FR) or high-fed (HF) (n = 3 × 14). At the age of 8 weeks, rats from each group were divided into two subgroups and given ICV, either ghrelin (G; 1 µg ghrelin/5 µl PBS, n = 7) or solvent alone (5 µl PBS, n = 7) every 24 h for 5 days. The immunohistochemical appearance and quantitative morphology of pituitary ACTH cells were evaluated, as well as peripheral ACTH and corticosterone levels. Central ghrelin administration increased (p<0.05) ACTH cell volumes in GNF, GFR and GHF rats by 8.1%, 11.8% and 9.1%, respectively, compared to the controls, while significant increases in ACTH cell volume density were observed in GNF and GHF rats. Circulating ACTH and corticosterone levels were elevated (p<0.05) in GNF and GFR rats by 72.8% and 80.8%, respectively, when compared to the corresponding controls. Thus, central ghrelin administration stimulated the pituitary-adrenal axis under preserved and negative energy balance states.

Genistein affects the morphology of pituitary ACTH cells and decreases circulating levels of ACTH and corticosterone in middle-aged male rats

The soybean phytoestrogen, genistein, is increasingly consumed as an alternative therapeutic for age-related diseases, namely cardiovascular conditions, cancer and osteoporosis. However, despite the beneficial effects on health, concern has been raised that this isoflavone also acts as an endocrine-disrupting chemical. The aim of this study was to examine the effects of genistein on immunohistomorphometric features of pituitary adrenocorticotropic cells (ACTH) and blood concentrations of ACTH and corticosterone in orchidectomized middle-aged male rats. Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and genistein-treated orchidectomized (Orx+G) groups. Genistein (30mg/kg/day) was administered subcutaneously for three weeks, while the control groups received the vehicle alone. ACTH cells were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure. Circulating concentrations of ACTH and corticosterone were measured by immunoassay. Orchidectomy reduced (p<0.05) the cell volume and the relative volume of ACTH cells in comparison to SO rats. Genistein treatment further decreased (p<0.05) these morphometric parameters and reduced (p<0.05) circulating ACTH and corticosterone concentrations by more than 20 percent in comparison to both Orx and SO rats. In conclusión, genistein modulated the immunohistomorphometric features of ACTH cells and decreased blood ACTH and corticosterone levels, which supports evidence that this isoflavone affects the hypothalamic-pituitary-adrenal axis and suppresses glucocorticoid hormone secretion.

Effect of different altitudes on the morphology of pituitary ACTH cells in rats / 医学研究生学报

Objective: To observe the morphologic changes of pituitary adrenocorticotrophic hormone (ACTH) cells in Wistar rats at different altitudes, and clarify the mechanism of stress reaction to hypoxia in ACTH cells. Methods: Wistar rats were divided into three groups and moved to different altitudes (1700 m, 3100 m, 4050 m). After 12 days, changes of ACTH cells were observed by using immunohistochemisty, image analysis and electron microscopy. Results:The ratio (R) of immunoreactive cell area to scanned area and mean optical density (A) increased at higher altitude with statistically different R values between groups of 1700 m and 4050 m (P