Zona Glomerulosa Research Articles

SUN-LB43 DLK1 Expressing Cells Contribute to the Zonation of the Adrenal Gland

The adrenal cortex is a dynamic organ that undergoes self-renewal and remodeling in response to the demand for steroids. In the mouse it is divided into two concentric layers, the outer zona glomerulosa and the inner zona fasciculata (ZF), that secrete aldosterone and corticosterone, respectively. Cell fate mapping studies have shown that the maintenance of the cortex relies on a pool of stem/progenitor cells located in the capsular and subcapsular compartments. Two interconnected cell populations have been identified, subcapsular undifferentiated cells secreting the morphogen Sonic Hedgehog (Shh) and capsular Gli1+ cells, which can transduce the Shh signal (1); both populations are precursors of steroidogenic cells and newly formed cells migrate in a centripetal fashion to repopulate the gland until they reach the juxtamedullary region where they undergo senescence and apoptosis. Moreover, our lab has shown that the Notch atypical ligand Delta-Like homologue 1 (Dlk1) is expressed in partially undifferentiated cells of the subcapsular region in rat (2)and human (3)adrenals, whilst it is mostly expressed in capsular cells in mice (4,5). To investigate whether Dlk1 expressing cells contribute to the zonation of the adrenal cortex we conducted lineage tracing analyses using a tamoxifen inducible Dlk1CreERT2mouse model carrying the R26tdTom reporter. Pregnant dames were injected with tamoxifen at embryonic day (e) 12.5 and pups were culled at postnatal day (p) 10 and p38. Analysis of tdTomato expression showed that 35% (p10) and 24% (p38) of Steroidogenic Factor 1(Sf1)+cortical cells were tdTomato+, revealing that capsular Dlk1+cells are steroidogenic precursors. On the other hand, postnatal tamoxifen injections (p0) showed tdTomato+/Sf1+ cells only in 1-2% in cortical cells after 24-months chase, suggesting that the contribution of Dlk1+cells to adrenocortical self-renewal is limited postnatally.However, the Dlk1+population could be reactivated in the adult mouse treated with dexamethasone and was shown to contribute to the regeneration of the ZF once dexamethasone treatment was ceased. 1. King P, et al. Shh signaling regulates adrenocortical development and identifies progenitors of steroidogenic lineages. Proc Natl Acad Sci(2009) 106:21185-211902. Guasti L, et al. Dlk1 Up-Regulates Gli1 Expression in Male Rat Adrenal Capsule Cells Through the Activation of β1 Integrin and ERK1/2. Endocrinology(2013) 154:4675-46843. Hadjidemetriou I, et al. DLK1/PREF1 marks a novel cell population in the human adrenal cortex. J Steroid Biochem Mol Biol(2019) 193:1054224. Guasti L, Candy Sze WC, McKay T, Grose R, King PJ. FGF signalling through Fgfr2 isoform IIIb regulates adrenal cortex development. Mol Cell Endocrinol(2013) 371:182-1885. Heikkilä M, et al. Wnt-4 Deficiency Alters Mouse Adrenal Cortex Function, Reducing Aldosterone Production. Endocrinology(2002) 143:4358-4365

Histological Study of the Adrenal Gland of the Adult Female Rabbit (Orycotolagus Cuniculus)

The aim of this study was to investigate the structure of the female rabbit adrenal gland by light microscopic observations. For this purpose, ten adrenals were collected from five adult female rabbits. The tissues were processed for light microscopy. The weight of rabbit gave mean values of 2.04k g and the mean values of long axis of left adrenal gland 15.46mm and the diameter of right gave mean values 11.30mm. The adrenal glands sit at the top of the kidneys,one on each side of the body, and have an inner core (known as the medulla) surrounded by an outer shell (known as the cortex). The adrenal cortex consists of three anatomic zones: the outer zona glomerulosa,; the intermediate zona fasciculata, which secretes cortisol; and the inner zona reticularis. The adrenal medulla, lying in the center of the adrenal gland, is functionally related to the sympathetic nervous system and secretes the catecholamines epinephrine and norepinephrine in response to stress.

Primary Aldosteronism in the Elderly.

The clinical spectrum and knowledge of the molecular mechanisms underlying primary aldosteronism (PA), the most frequent form of endocrine hypertension, has evolved over recent years. In accordance with the Endocrine Society guidelines and in light of the growing evidence showing adverse cardiovascular outcomes, it is expected that a progressively wider population of patients affected by hypertension will be screened for PA, including the elderly. A systematic search of PubMed was undertaken for studies related to the renin-angiotensin-aldosterone system (RAAS), PA, and adrenal histopathology in the elderly population. Several studies showed an age-dependent decrease in the activity of RAAS, together with a progressive decrease of the aldosterone response to sodium intake, particularly after the sixth decade of life. The positive correlation between age and serum aldosterone during liberal sodium intake over serum aldosterone during sodium restriction is paralleled by histological changes in adrenal aldosterone synthase (CYP11B2) expression patterns. Immunohistochemical studies showed a progressive loss of the continuous expression of CYP11B2 in the adrenal zona glomerulosa with aging and a concomitant increase of aldosterone-producing cell clusters, which might be responsible for relatively autonomous aldosterone production. Additionally, following PA confirmation and subtype diagnosis, older age is correlated with a lower benefit after adrenalectomy for unilateral PA. Accumulating evidence suggests that RAAS physiology and regulation show age-related changes. Further studies may investigate to what extent these variations might affect the diagnostic workup of patients affected by PA.

\u03b2-Catenin and FGFR2 regulate postnatal rosette-based adrenocortical morphogenesis

Rosettes are widely used in epithelial morphogenesis during embryonic development and organogenesis. However, their role in postnatal development and adult tissue maintenance remains largely unknown. Here, we show zona glomerulosa cells in the adult adrenal cortex organize into rosettes through adherens junction-mediated constriction, and that rosette formation underlies the maturation of adrenal glomerular structure postnatally. Using genetic mouse models, we show loss of β-catenin results in disrupted adherens junctions, reduced rosette number, and dysmorphic glomeruli, whereas β-catenin stabilization leads to increased adherens junction abundance, more rosettes, and glomerular expansion. Furthermore, we uncover numerous known regulators of epithelial morphogenesis enriched in β-catenin-stabilized adrenals. Among these genes, we show Fgfr2 is required for adrenal rosette formation by regulating adherens junction abundance and aggregation. Together, our data provide an example of rosette-mediated postnatal tissue morphogenesis and a framework for studying the role of rosettes in adult zona glomerulosa tissue maintenance and function.

Angiotensin II induces coordinated calcium bursts in aldosterone-producing adrenal rosettes

Aldosterone-producing zona glomerulosa (zG) cells of the adrenal gland arrange in distinct multi-cellular rosettes that provide a structural framework for adrenal cortex morphogenesis and plasticity. Whether this cyto-architecture also plays functional roles in signaling remains unexplored. To determine if structure informs function, we generated mice with zG-specific expression of GCaMP3 and imaged zG cells within their native rosette structure. Here we demonstrate that within the rosette, angiotensin II evokes periodic Cav3-dependent calcium events that form bursts that are stereotypic in form. Our data reveal a critical role for angiotensin II in regulating burst occurrence, and a multifunctional role for the rosette structure in activity-prolongation and coordination. Combined our data define the calcium burst as the fundamental unit of zG layer activity evoked by angiotensin II and highlight a novel role for the rosette as a facilitator of cell communication.

Very Low‐Density Lipoprotein and a Sphingosine‐1‐Phosphate Receptor Agonist Regulate Aldosterone Production via Lipin‐1 in Human Adrenocortical Cells

Aldosterone plays an important role in blood pressure homeostasis, and hyperaldosteronism can result in hypertension. Aldosterone is considered to be a link between hypertension and obesity; obese individuals have high serum levels of very low‐density lipoprotein (VLDL). VLDL has been shown to stimulate aldosterone production in multiple zona glomerulosa cell models via phospholipase D (PLD), an enzyme that hydrolyzes phosphatidylcholine to phosphatidic acid (PA), a lipid second messenger. In addition, sphingosine‐1‐phosphate (S1P), a bioactive sphingolipid also elevated in obesity, has been reported to be a novel stimulator of aldosterone secretion and PLD activity. The mechanisms underlying the action of these non‐conventional secretagogues of aldosterone remain to be elucidated. Angiotensin II, a classical aldosterone secretagogue, not only activates PLD but also elevates the expression of lipin‐1, an enzyme that converts PA to another lipid second messenger, diacylglycerol (DAG), in human adrenocortical carcinoma (HAC15) cells. However, it is unclear which of the two lipid signals, PA or DAG, underlies PLD’s role in aldosterone production. Herein, we used HAC15 cells to determine whether VLDL and an S1P1 receptor (S1PR1) agonist (SEW2871) stimulate aldosterone production by increasing steroidogenic gene expression via lipin‐1‐mediated metabolism of PA to DAG. We overexpressed lipin‐1 using an adenovirus or inhibited it using propranolol followed by treatment with or without VLDL or SEW2871 for 24 h. The expression of steroidogenic genes and aldosterone secretion were monitored using qRT‐PCR and radioimmunoassay. We demonstrated that lipin‐1 overexpression enhanced the VLDL‐stimulated 55‐fold increase in CYP11B2 expression by 75% while lipin‐1 inhibition decreased the VLDL‐stimulated 21‐fold increase in CYP11B2 expression by 66%. A parallel trend was observed with aldosterone secretion levels: VLDL‐stimulated increase in aldosterone production was enhanced by lipin‐1 overexpression (182%) and was decreased by propranolol (80%). Similar results were obtained with SEW2871. Our results are, therefore, suggestive of DAG being the key lipid signal since lipin‐1 regulates VLDL‐ and S1PR1 agonist‐stimulated expression of steroidogenic genes and ultimately, aldosterone production. Our study warrants further investigation into these steroidogenic signaling pathways which can lead to the identification of novel therapeutic targets such as lipin‐1, or its downstream pathways, to potentially treat obesity‐associated hypertension.Support or Funding InformationThis work was supported in part by the Augusta University Adrenal Center. WBB was also supported by VA Merit Award #BX001357.

Beta-Catenin Causes Adrenal Hyperplasia by Blocking Zonal Transdifferentiation

SUMMARYActivating mutations in the canonical Wnt/β-catenin pathway are key drivers of hyperplasia, the gateway for tumor development. In a wide range of tissues, this occurs primarily through enhanced effects on cellular proliferation. Whether additional mechanisms contribute to β-catenin-driven hyperplasia remains unknown. The adrenal cortex is an ideal system in which to explore this question, as it undergoes hyperplasia following somatic β-catenin gain-of-function (βcat-GOF) mutations. Targeting βcat-GOF to zona Glomerulosa (zG) cells leads to a progressive hyperplastic expansion in the absence of increased proliferation. Instead, we find that hyperplasia results from a functional block in the ability of zG cells to transdifferentiate into zona Fasciculata (zF) cells. Mechanistically, zG cells demonstrate an upregulation of Pde2a, an inhibitor of zF-specific cAMP/PKA signaling. Hyperplasia is further exacerbated by trophic factor stimulation leading to organomegaly. Together, these data indicate that β-catenin drives adrenal hyperplasia through both proliferation-dependent and -independent mechanisms.

Histoarchitectural changes of Adrenal gland in Emballonurid male bat, Taphozous longimanus (Hardwicke) during the reproductive cycle

Taphozous longimanus has two adrenal glands, one on each side, situated retroperitoneally occupying an antero-mesial position abutting against the ipsilateral kidney. The left adrenal gland is pyramidal and the right adrenal gland is oval in shape. The diameter of the left adrenal gland is always higher than that of the right adrenal gland during different periods of reproductive activity. Each gland is duplex organ consisting of cortex and medulla. Cortex is divided into two zones which are poorly differentiated from each other. An outer zone is zona glomerulosa, and inner zone is zona fasciculata. The zona glomerulosa of left and right adrenal gland during the breeding period are larger than that of zona glomerulosa of left and right adrenal gland during the pre-breeding period respectively. The diameter of zona fasciculata of left and right adrenal gland during the breeding period is smaller than that of zona fasciculata of left and right adrenal gland of the pre-breeding period. There is no clear histological difference between medulla of right adrenal gland to that of left adrenal gland during the breeding period but the diameter of zona glomerulosa and medulla during the breeding period is larger than that of the pre-breeding period.

The adrenal cortex after estradiol or daidzein application in a rat model of the andropause: Structural and hormonal study

Introduction and AimDaidzein application may represent an effective and less harmful alternative to indicated, classical estrogenization of ageing men. The aim of this study was to perform structural and hormonal analysis of the adrenal cortex, after estradiol or daidzein supplementation in a rat model of the andropause. Material and methodsMiddle-aged Wistar rats were divided into sham operated (SO; n = 8), orchidectomized (Orx; n = 8), estradiol treated orchidectomized (Orx + E; n = 8) and daidzein treated orchidectomized (Orx + D; n = 8) groups. Estradiol (0.625 mg/kg b.m./day) or daidzein (30 mg/kg b.m./day) were administered subcutaneously for three weeks, while the SO and Orx groups received the vehicle alone. Set objectives were achieved using stereology, histochemistry/immunohistochemistry, immunoassays and ultrastructural analysis. ResultsBoth estradiol and daidzein treatment significantly increased volumes of the zona glomerulosa cell and nuclei, but decreased circulating aldosterone levels. Estradiol markedly increased volumes of the zona fasciculata cell and nuclei in parallel with significant decrease of the adrenal tissue level of corticosterone, while daidzein significantly decreased both the adrenal and circulating levels of corticosterone. Serum DHEA level and volumes of the zona reticularis cell and nuclei significantly increased upon estradiol treatment, whereas daidzein even stronger increased the circulating level of DHEA. Shunting of the corticosteroidogenesis pathways towards adrenal androgens production, after the treatments, corresponded to the ultrastructural findings and zonal capillary network rearrangements. ConclusionsGiven the coherence of its effects and relative safety, daidzein could be the remedy of choice for the treatment of ageing-caused androgen deprivation and the hypothalamo-pituitary-adrenal axis hyperfunction/related metabolic issues in males.

Biometry of Adrenal Glands of Mixed-Breed Dogs

Background: Differences of the size of the adrenal glands, in healthy dogs or in endocrinopathies, undermine correct diagnosis of endocrine disorders and evaluations of the adrenal cortex in relation to its size and possible correlation with endocrinopathies are rare. The aim of the present study was to perform measurements of the length, width, thickness and weight of the adrenal glands of young, adult and elderly mixed-breed dogs and correlate them with the age, sex and weight of animals. In addition, the areas occupied by the zona glomerulosa, zona fasciculata, and zona reticularis of the adrenal cortex were measured in order to establish a microscopic biometric pattern.Material, Methods & Results: The right and left adrenal glands of 12 young (six females and six males), 12 adults (six females and six males), and 12 elderly (six females and six males), all mongrels, derived from routine and necropsied in the Animal Pathology Sector of the Veterinary Hospital of the Federal University of Espírito Santo (HOVET-UFES) were weighed and the length, width, and thickness were measured. For the microscopic measurement of the adrenal cortex, 10 randomly selected samples were submitted to routine histological processing and the microscope slides were observed under a light microscope at 5× and 10× objectives, photodocumented and measurements were obtained from a random portion of the adrenal cortex and the zones composing the cortex were measured in triplicate with the aid of the computerized image analysis software. The left adrenal showed a greater average length than the right adrenal in young, adult, and elderly dogs. The size of the glands in the young and adult dogs is not influenced by the sex of the animals, but in older dogs the females had a greater mean width than the males. The weight of the animals presented a positive correlation in relation to the length and weight of the right and left adrenal glands in all studied groups. The age did not influence the length and weight variables of the glands. However, some differences in thickness and width were observed in the elderly group compared to those in other groups. For the microscopic measurements in the right adrenal gland, the cortex was 1.53 mm, being 0.21 mm for the glomerular zone (14.6% of the total adrenal cortex), 1.04 mm for the zona fasciculata (66.9%), and 0.29 mm for the zona reticularis (18.5%). In the left adrenal gland, the cortex was 1.83 mm, being 0.23 mm for the glomerular zone (13.2% of the total adrenal cortex), 1.23 mm for the zona fasciculata (63.96%), and 0.37 for the zona reticularis (22.84%).Discussion: Studies on the size of the adrenal gland in dogs using macroscopic biometrics are scarce, and the current study presents results regarding mixed-breed (male and female) dogs of different ages, which presented variation in size and weight, which could also influence the size of the adrenal gland. Thus, it can be observed that a variation of measurements can be found, especially for dogs with no defined breed. These results demonstrate the importance of studies that perform the macroscopic analysis of such glands. It was concluded that there was a clear variation in the size of the adrenal glands in mixed-breed dogs of different ages and both sexes; the left adrenal showed greater lengths and weights than the right gland. The sex of the animals did not influence the size of the glands in young and adult dogs, but in elderly dogs, the females showed a greater mean width than the males. The right and left adrenal cortices are formed at a greater percentage by the zona fasciculata, followed by the zona reticularis and zona glomerulosa.

Adrenal cortex hypoxia modulates aldosterone production in heart failure

Plasma aldosterone concentration increases in proportion to the severity of heart failure, even during treatment with renin-angiotensin system inhibitors. This study investigated alternative regulatory mechanisms of aldosterone production that are significant in heart failure. Dahl salt-sensitive rats on a high-salt diet, a rat model of heart failure with cardio-renal syndrome, had high plasma aldosterone levels and elevated β3-adrenergic receptor expression in hypoxic zona glomerulosa cells. In H295R cells (a human adrenocortical cell line), hypoxia-induced β3-adrenergic receptor expression. Hypoxia-mediated β3-adrenergic receptor expression augmented aldosterone production by facilitating hydrolysis of lipid droplets though ERK-mediated phosphorylation of hormone-sensitive lipase, also known as cholesteryl ester hydrolase. Hypoxia also accelerated the synthesis of cholesterol esters by acyl-CoA:cholesterol acyltransferase, thereby increasing the cholesterol ester content in lipid droplets. Thus, hypoxia enhanced aldosterone production by zona glomerulosa cells via promotion of the accumulation and hydrolysis of cholesterol ester in lipid droplets. In conclusion, hypoxic zona glomerulosa cells with heart failure show enhanced aldosterone production via increased catecholamine responsiveness and activation of cholesterol trafficking, irrespective of the renin-angiotensin system.

Mass Spectrometry Imaging Establishes 2 Distinct Metabolic Phenotypes of Aldosterone-Producing Cell Clusters in Primary Aldosteronism.

Aldosterone-producing adenomas (APAs) are one of the main causes of primary aldosteronism and the most prevalent surgically correctable form of hypertension. Aldosterone-producing cell clusters (APCCs) comprise tight nests of zona glomerulosa cells, strongly positive for CYP11B2 (aldosterone synthase) in immunohistochemistry. APCCs have been suggested as possible precursors of APAs because they frequently carry driver mutations for constitutive aldosterone production, and a few adrenal lesions with histopathologic features of both APCCs and APAs have been identified. Our objective was to investigate the metabolic phenotypes of APCCs (n=27) compared with APAs (n=6) using in situ matrix-assisted laser desorption/ionization mass spectrometry imaging of formalin-fixed paraffin-embedded adrenals from patients with unilateral primary aldosteronism. Specific distribution patterns of metabolites were associated with APCCs and classified 2 separate APCC subgroups (subgroups 1 and 2) indistinguishable by CYP11B2 immunohistochemistry. Metabolic profiles of APCCs in subgroup 1 were tightly clustered and distinct from subgroup 2 and APAs. Multiple APCCs from the same adrenal displayed metabolic profiles of the same subgroup. Metabolites of APCC subgroup 2 were highly similar to the APA group and indicated enhanced metabolic pathways favoring cell proliferation compared with APCC subgroup 1. In conclusion, we demonstrate specific subgroups of APCCs with strikingly divergent distribution patterns of metabolites. One subgroup displays a metabolic phenotype convergent with APAs and may represent the progression of APCCs to APAs.

GRK2-Mediated Crosstalk Between β-Adrenergic and Angiotensin II Receptors Enhances Adrenocortical Aldosterone Production In Vitro and In Vivo.

Aldosterone is produced by adrenocortical zona glomerulosa (AZG) cells in response to angiotensin II (AngII) acting through its type I receptors (AT1Rs). AT1R is a G protein-coupled receptor (GPCR) that induces aldosterone via both G proteins and the adapter protein βarrestin1, which binds the receptor following its phosphorylation by GPCR-kinases (GRKs) to initiate G protein-independent signaling. β-adrenergic receptors (ARs) also induce aldosterone production in AZG cells. Herein, we investigated whether GRK2 or GRK5, the two major adrenal GRKs, is involved in the catecholaminergic regulation of AngII-dependent aldosterone production. In human AZG (H295R) cells in vitro, the βAR agonist isoproterenol significantly augmented both AngII-dependent aldosterone secretion and synthesis, as measured by the steroidogenic acute regulatory (StAR) protein and CYP11B2 (aldosterone synthase) mRNA inductions. Importantly, GRK2, but not GRK5, was indispensable for the βAR-mediated enhancement of aldosterone in response to AngII. Specifically, GRK2 inhibition with Cmpd101 abolished isoproterenol’s effects on AngII-induced aldosterone synthesis/secretion, whereas the GRK5 knockout via CRISPR/Cas9 had no effect. It is worth noting that these findings were confirmed in vivo, since rats overexpressing GRK2, but not GRK5, in their adrenals had elevated circulating aldosterone levels compared to the control animals. However, treatment with the β-blocker propranolol prevented hyperaldosteronism in the adrenal GRK2-overexpressing rats. In conclusion, GRK2 mediates a βAR-AT1R signaling crosstalk in the adrenal cortex leading to elevated aldosterone production. This suggests that adrenal GRK2 may be a molecular link connecting the sympathetic nervous and renin-angiotensin systems at the level of the adrenal cortex and that its inhibition might be therapeutically advantageous in hyperaldosteronism-related conditions.

L- and T-type calcium channels control aldosterone production from human adrenals.

Aldosterone, which plays a key role in the regulation of blood pressure, is produced by zona glomerulosa (ZG) cells of the adrenal cortex. Exaggerated overproduction of aldosterone from ZG cells causes primary hyperaldosteronism. In ZG cells, calcium entry through voltage-gated calcium channels plays a central role in the regulation of aldosterone secretion. Previous studies in animal adrenals and human adrenal adrenocortical cell lines suggest that the T-type but not the L-type calcium channel activity drives aldosterone production. However, recent clinical studies show that somatic mutations in L-type calcium channels are the second most prevalent cause of aldosterone-producing adenoma. Our objective was to define the roles of T and L-type calcium channels in regulating aldosterone secretion from human adrenals. We find that human adrenal ZG cells mainly express T-type CaV3.2/3.3 and L-type CaV1.2/1.3 calcium channels. TTA-P2, a specific inhibitor of T-type calcium channel subtypes, reduced basal aldosterone secretion from acutely prepared slices of human adrenals. Surprisingly, nifedipine, the prototypic inhibitor of L-type calcium channels, also decreased basal aldosterone secretion, suggesting that L-type calcium channels are active under basal conditions. In addition, TTA-P2 or nifedipine also inhibited aldosterone secretion stimulated by angiotensin II- or elevations in extracellular K+. Remarkably, blockade of either L- or T-type calcium channels inhibits basal and stimulated aldosterone production to a similar extent. Low concentrations of TTA-P2 and nifedipine showed additive inhibitory effect on aldosterone secretion. We conclude that T- and L-type calcium channels play equally important roles in controlling aldosterone production from human adrenals.

Morphofunctional rearrangements of adrenal cortex of adult rats at the experimental microelementosis

Xenobiotics, including salts of heavy metals, determine the development of pathology of individual organs and systems of the body. Adrenal hormones occupy a key place in the regulation and maintenance of the organism basic functions. The study of morphological, biochemical and immunohistochemical changes in the adrenal cortex of pubescent male rats at exposure to the complex of heavy metal salts remains an actual aspect of modern morphology. The experiment involved 24 white adult male rats weighing 250–300 g, aged 7–8 months. The animals of the experimental group consumed ordinary drinking water saturated with a combination of heavy metal salts (Zn, Cu, Fe, Mg, Cr) for 60 days. Histological, biochemical (determination of the content of hormones COR – cortisol, DHS – dehydroepiandrosterone sulfate) and immunohistochemical (determination of the expression of proliferation marker Ki-67) methods were used. Long-term consumption of the combination of heavy metals salts by mature rats leads to thickening of the stromal component of the gland, the rupture of capillaries and the violation of rheological properties of blood. Chromatin condensation, its marginal location, and initial stages of necrobiotic changes have been found in the spongiocyte nuclear apparatus. For endocrinocytes of the zona glomerulosa and zona reticularis of the gland, a slight increase in proliferative activity has been revealed, while cells of the zona fasciculata were non-reactive. These results correlate with the results of biochemical research, according to which hormones of the zona reticularis – DHS were actively involved in the formation of adaptive reactions in the body of experimental animals at the 60-day period of administration of the complex of heavy metals salts. The results of complex studies indicate a weakening of the secretory activity of cells of the zona fasciculata, which adversely affects the development of compensatory-adaptive processes in the body and the course of the general adaptation syndrome in response to the action of the damaging agent.

SIÇAN BÖBREKÜSTÜ BEZİNİN HİSTOLOJİK YAPISI ÜZERİNE ELEKTROMANYETİK ALANIN ETKİSİNİN STEREOLOJİK YÖNTEMLE ARAŞTIRILMASI

Objective: Cell phone emitting electromagnetic field (EMF) are routinely used in our daily life. Long-term use of these Cell phones has caused public health concerns in recent years. Also, reports regarding the effect of EMF exposure on the biosystem are inconclusive. In this study, we aimed to investigate the possible effects of 900 MHz EMA on the adrenal glands of adult male rats. Method: Twelve adult rats were randomly selected and divided into two groups as follow: control and EMF. Finally, we analysed the suprarenal gland tissues using stereological method. Results: We found no significant difference in the volume of the adrenal zona glomerulosa d in the EMF group compared to the control group. The volume of the adrenal zona fasciculate was significantly increased In the EMF group compared to the control group (p<0.05). There was also significant increase in the mean volume of the zona reticularis (p< 0.05). Conclusion: Our finding showed that exposure to 900 MHz EMF caused morphometrical change in the rat adrenal gland.

Evaluation of subchronic repeated administration toxicity of ammonium nitrate in rats.

Ammonium nitrate is a chemical mostly used in agriculture and munitions to produce fertilizers and explosives, respectively. Its annual production and consumption exceed ten million tons. Despite is diverse uses, large production and consumption, and occupational risk, information on the toxicity that results from oral exposure to ammonium nitrate is limited. In this study, the safety of ammonium nitrate was therefore evaluated by observing its subchronic toxicity in rats. Ammonium nitrate (0, 100, 300 and 1000mg/kg/day) was orally administered by gavage to rats at 5 times/week for 13weeks. Reversibility of the effects of 1000mg/kg/day was assessed in rats after 2weeks. Mortality, clinical signs, body weight, and food consumption were monitored. Hematology, serum chemistry, urinalysis, organ weight, necropsy, and histopathology were performed. Salivation was intermittently observed in both sexes receiving 300 and 1000mg/kg/day ammonium nitrate, which normalized 2weeks post-treatment. Urine volume increased in both sexes receiving 1000mg/kg/day ammonium nitrate. Urine pH decreased in both sexes of all dosing groups when compared with the concurrent control group. Urinary changes normalized 2weeks post-treatment. Blood urea nitrogen levels increased in males receiving 1000mg/kg/day, but normalized 2weeks later. Potassium level in males and sodium and chloride levels in both sexes receiving 1000mg/kg/day ammonium nitrate decreased, but normalized 2weeks later. Hypertrophy of zona glomerulosa in the adrenals was observed in both sexes receiving 1000mg/kg/day and in females receiving 300mg/kg/day ammonium nitrate. After a 2-week recovery period, the same lesion was observed in one female receiving 1000mg/kg/day ammonium nitrate. Our results indicate that ammonium nitrate induces reversible salivation, increases BUN levels, induces acidic diuresis with decreases in sodium, potassium, and chloride levels, and induces ZG hypertrophy. These results shed light on the toxicity profile of ammonium nitrate.

Regulation of the KCNJ5 gene by SF-1 in the adrenal cortex: Complete genomic organization and promoter function

Activating mutations in the KCNJ5 gene are responsible for the significant number of aldosterone-producing adenomas. To elucidate the molecular mechanisms underlying KCNJ5 expression, we characterized the entire human KCNJ5 gene. The gene spanned approximately 29.8 kb and contained three exons and two introns. The strongest expression of KCNJ5 mRNA was observed in the adrenal gland. The promoter region contained a putative binding site for SF-1 at −1782 bp. A construct containing −2444 bp of the promoter region exhibited the strongest promoter activity in adrenal H295R cells, and the introduction of a mutation in the SF-1 binding site almost completely abolished promoter activity. Furthermore, deletion mutation, EMSA, and knockdown analyses revealed that SF-1 bound to this element and was functional. Immunochemistry showed that KCNJ5 was predominantly expressed in the zona glomerulosa, while SF-1 was ubiquitously expressed in the adrenal cortex. These results demonstrated that SF-1 mediates the expression of human KCNJ5 in the adrenal cortex.

Chemogenetic activation of adrenocortical Gq signaling causes hyperaldosteronism and disrupts functional zonation.

The mineralocorticoid aldosterone is produced in the adrenal zona glomerulosa (ZG) under the control of the renin-angiotensin II (AngII) system. Primary aldosteronism (PA) results from renin-independent production of aldosterone and is a common cause of hypertension. PA is caused by dysregulated localization of the enzyme aldosterone synthase (Cyp11b2), which is normally restricted to the ZG. Cyp11b2 transcription and aldosterone production are predominantly regulated by AngII activation of the Gq signaling pathway. Here, we report the generation of transgenic mice with Gq-coupled designer receptors exclusively activated by designer drugs (DREADDs) specifically in the adrenal cortex. We show that adrenal-wide ligand activation of Gq DREADD receptors triggered disorganization of adrenal functional zonation, with induction of Cyp11b2 in glucocorticoid-producing zona fasciculata cells. This result was consistent with increased renin-independent aldosterone production and hypertension. All parameters were reversible following termination of DREADD-mediated Gq signaling. These findings demonstrate that Gq signaling is sufficient for adrenocortical aldosterone production and implicate this pathway in the determination of zone-specific steroid production within the adrenal cortex. This transgenic mouse also provides an inducible and reversible model of hyperaldosteronism to investigate PA therapeutics and the mechanisms leading to the damaging effects of aldosterone on the cardiovascular system.

Peculiarities of microstructure of the suprarenal glands of rabbits with different types of autonomic tone

The article investigates the structure of the suprarenal (adrenal) glands of male rabbits (Oryctolagus cuniculus), in which, on the basis of electrocardiographic and variational-pulsometric studies, different types of autonomic tone were observed. This allowed the animals to be divided into three groups: 1) sympathicotonic rabbits; 2) normotonic rabbits; 3) parasympathicotonic rabbits. The animals of the first two groups were characterized by almost the same body weight, while weight of the rabbits of the third group was slightly higher. After euthanasia, the suprarenal glands were extracted for histological and histochemical analyses. Morphometric study of histopreparations revealed that in the normotonic rabbits the thickness of the zona glomerulosa and zona fasciculata of the suprarenal glands were of average sizes, and the area of the medulla was the smallest. The parasympathicotonic rabbits had the thickest zona glomerulosa and greatest area of the medulla, but the thinnest zona fasciculata. The sympathicotonic rabbits were observed to have the greatest thickness of the zona fasciculata of the suprarenal glands, the area of the medulla was of average values, and the thickness of the zona glumerulosa was of minimum value. The type of autonomic tone also manifests in the saturation of each of the zones with cells. The normotonic rabbits were observed to have the highest number of cells per area of 1,000 µm² in the zona fasciculata and the medulla, sympathicotonic rabbits – in the zona glomerulosa and zona reticularis, and in parasympathicotonic rabbits this parameter had average or lowest values in all the zones. The sizes of cells and their structural parts were characterized on the basis of nuclear-cytoplasmic ratio. In the zona fasciculata and medulla this parameter was highest among parasympathicotonic rabbits, and lowest in sympathicotonic rabbits. In the zona glomerulosa, almost equal values were observed in the normotonic and parasympathicotonic rabbits, while being reliably lower in sympathicotonic rabbits. By the value of nuclear-cytoplasmic ratio in the zona reticularis, the normotonic rabbits dominated, followed by the sympathicotonic animals, and the parasympathicotonic rabbits had the lowest parameters.