Zona Reticularis Cells Research Articles

Preliminary investigation reveals novel pathological consequences of bluetongue virus-1 infection in the endocrine glands of pregnant Indian sheep

Bluetongue virus (BTV), a major peril to the sheep industry, infects a wide range of the cells in the infected animals including mononuclear, dendritic and epithelial cells. However, little is known about its tropism for the secretory epithelial cells of endocrine glands and the pathogenesis it induces. The aim of the study was to assess the BTV load, antigen distribution in the tissue of the pituitary, thyroid as well as adrenal glands and associated histopathological consequences. BTV antigens were localized using immunohistochemistry in the thyroid’s epithelial cells, zona fasciculata and zona reticularis cells and the anterior pituitary epithelial cells. The real-time PCR portrayed the high viral load in adrenals at 7th days postinoculation (DPI) and in thyroid and pituitary glands at 15th DPI. Serum examination revealed variation in the T-3 and T-4 of infected animals in comparison to the control group. Caspase-3 immunolocalization revealed BTV-1 induces apoptosis in the affected cells of endocrine gland of infected animals. Further, this study signifies the tropism of BTV in the novel sites (endocrine glands) of the host that might be one of the reasons for the poor performance of infected animals.

Cellular Senescence in Adrenocortical Biology and Its Disorders.

Cellular senescence is considered a physiological process along with aging and has recently been reported to be involved in the pathogenesis of many age-related disorders. Cellular senescence was first found in human fibroblasts and gradually explored in many other organs, including endocrine organs. The adrenal cortex is essential for the maintenance of blood volume, carbohydrate metabolism, reaction to stress and the development of sexual characteristics. Recently, the adrenal cortex was reported to harbor some obvious age-dependent features. For instance, the circulating levels of aldosterone and adrenal androgen gradually descend, whereas those of cortisol increase with aging. The detailed mechanisms have remained unknown, but cellular senescence was considered to play an essential role in age-related changes of the adrenal cortex. Recent studies have demonstrated that the senescent phenotype of zona glomerulosa (ZG) acts in association with reduced aldosterone production in both physiological and pathological aldosterone-producing cells, whereas senescent cortical-producing cells seemed not to have a suppressed cortisol-producing ability. In addition, accumulated lipofuscin formation, telomere shortening and cellular atrophy in zona reticularis cells during aging may account for the age-dependent decline in adrenal androgen levels. In adrenocortical disorders, including both aldosterone-producing adenoma (APA) and cortisol-producing adenoma (CPA), different cellular subtypes of tumor cells presented divergent senescent phenotypes, whereby compact cells in both APA and CPA harbored more senescent phenotypes than clear cells. Autonomous cortisol production from CPA reinforced a local cellular senescence that was more severe than that in APA. Adrenocortical carcinoma (ACC) was also reported to harbor oncogene-induced senescence, which compensatorily follows carcinogenesis and tumor progress. Adrenocortical steroids can induce not only a local senescence but also a periphery senescence in many other tissues. Therefore, herein, we systemically review the recent advances related to cellular senescence in adrenocortical biology and its associated disorders.

Effect of induced hepatic ischemia–reperfusion on the adrenal cortex of adult male albino rats and the possible protective role of L-arginine: Biochemical, histological and immunohistochemial study

Hepatic ischemia reperfusion injury (IRI) takes place through liver transplantation. Hepatic IRI might seriously affect liver function and is reported to be accountable for 15 % of organ failure and could result in multi-organ dysfunction syndrome (MODS) that lead to high rates of morbidity and mortality. L-arginine (L-Arg) could reduce hepatic IRI via different mechanisms Objective: To estimate the effect of hepatic ischemic reperfusion (I/R) and the possible protective effect of L-Arg. on the adrenal cortex. Materials & Methods: Thirty two albino rats were utilized in the current work. The animals split to Sham-Operation, L-Arg , ischemic reperfusion, I/R group and I/R and L-Arg group. Then, at the assigned time, blood samples were assembled for biochemical study. Histological and immunohistochemical studies were performed on the adrenal tissueResults: The adrenal cortex of I/R group exhibited architecture loss of the three zones. Zona glomerulosa cells showed small pyknotic nuclei and vacuolated cytoplasm. Zona fasciculata cells appeared ballooned with small pyknotic nuclei. Also, karyolitic nuclei were seen. zona reticularis cells showed pyknotic nuclei and vacuolated cytoplasm and separated by congested blood sinusoids. Hyaline material depositions were seen. Biochemical study revealed a marked increase in serum levels of liver enzymes, excess in the MDA level and a marked reduction in the CAT level compared to control group. These changes were ameliorated by L-Arg.Conclusion: hepatic I/R has been proved to induce histological changes of the adrenal cortex which could be ameliorated by administration of L-Arg. Therefore, For inhibiting or reducing hepatic IRI through liver surgery, an effective method is urgently required.

The Adrenal Cortex, an Underestimated Site of SARS-CoV-2 Infection.

BackgroundThe majority of the critically ill patients may have critical illness-related corticosteroid insufficiency (CIRCI). The therapeutic effect of dexamethasone may be related to its ability to improve cortical function. Recent study showed that dexamethasone can reduce COVID-19 deaths by up to one third in critically ill patients. The aim of this article is to investigate whether SARS-CoV-2 can attack the adrenal cortex to aggravate the relative adrenal insufficiency.MethodsWe summarized the clinical features of COVID-19 reported in currently available observational studies. ACE2 and TMPRSS2 expression was examined in human adrenal glands by immunohistochemical staining. We retrospectively analyzed serum cortisol levels in critically ill patients with or without COVID-19.ResultsHigh percentage of critically ill patients with SARS-COV-2 infection in the study were treated with vasopressors. ACE2 receptor and TMPRSS2 serine protease were colocalized in adrenocortical cells in zona fasciculata and zona reticularis. We collected plasma cortisol concentrations in nine critically ill patients with COVID-19. The cortisol levels of critically ill patients with COVID-19 were lower than those in non-COVID-19 critically ill group. Six of the nine COVID-19 critically ill patients had random plasma cortisol concentrations below 10 µg/dl, which met the criteria for the diagnosis of CIRCI.ConclusionWe demonstrate that ACE2 and TMPRSS2 are colocalized in adrenocortical cells, and that the cortisol levels are lower in critically ill patients with COVID-19 as compared to those of non-COVID-19 critically ill patients. Based on our findings, we recommend measuring plasma cortisol level to guide hormonal therapy.

SUN-210 Differentially Expressed Mirnas in Zona Reticularis (ZR) Cells of the Human Adrenal Cortex

The human adrenal cortex, involved in adaptive responses to stress, fluid homeostasis, and secondary sexual characteristics, arises from a tightly regulated development of a zone and cell type-specific secretory pattern. However, the molecular mechanisms governing adrenal zonation, particularly postnatal ZR development, which produces adrenal androgens in a life-time-specific manner, remain poorly understood. The hallmark of ZR is the low expression of type 2 3β-hydroxysteroid dehydrogenase (HSD3B2). However, the mechanisms underlying HSD3B2 downregulation in the ZR remain unknown. MiRNAs are seen as regulators of cell phenotypes. The objective of the study was to compare miRNA expression profiles in human adrenal ZR and zona fasciculata (ZF). ZF and ZR were microdissected from human adrenals tissues (n=5, from boys aged 16, 17 and 19 yr and girls aged 12 and 16 yr) by laser capture microdissection (LCM). Total RNA was extracted from 5 ZF/ZR pairs and next-generation sequencing (NGS) was used to perform the microRNA expression profiling. 281 mature microRNAs were identified in human adrenal cortex. Among them, 7 microRNAs were significantly differentially expressed between ZF and ZR. The expression of miR-375-3p, miR-483-3p and miR-7-5p was higher in ZR compared with its paired ZF by 2-fold or greater. Multiple available bioinformatic algorithms (TargetScan, miRanda, DianaLab and PicTar) were employed to search for its target genes. Among predicted target genes, several genes (GATA-6, GATA-4, SF1, NR4A2, and IGF-1) are known to be involved in HSD3B2 regulation. In summary, LCM combined with NGS provided a robust approach to explore the adrenal zone-specific micro-RNA profiling. Our data gave first hints that miRNAs might be novel regulatory modules associated with human adrenal ZR cell-specific transcript regulation underlying developmental androgen production.

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.

Correlation Between Telomere Attrition of Zona Fasciculata and Adrenal Weight Reduction in Older Men.

Although numerous theories are reported on sex differences in longevity, the underlying biological mechanisms remain unknown. We previously reported that telomere length in the zona reticularis cells of the human adrenal cortex was significantly longer in older than that in younger subjects. However, we could not evaluate sex differences in the telomere lengths. To compare the telomere lengths of adrenocortical and adrenal medullar cells between men and women from infancy through older adulthood. Adrenal glands of 30 male (aged 0 to 100 years) and 25 female (aged 0 to 104 years) autopsied subjects were retrieved from autopsy files. Using quantitative fluorescence in situ hybridization, relative telomere lengths were determined in the parenchymal cells of the 3 adrenocortical zones and medulla. Age-related changes in the weight of adrenal glands were also investigated. Older male subjects (aged 65 years or older) had significantly shorter telomere lengths in zona fasciculata (ZF) cells compared to the corresponding female subjects. In men, older subjects exhibited a significant age-related reduction in adrenal weight; however, no age-related changes in adrenal weight were detected in women. Telomere attrition of ZF cells was correlated with adrenal weight reduction in older men but not in older women, suggesting a decreased number of ZF cells in older men. This may help us understand the possible biological mechanisms of sex difference in longevity of humans.

The possible structural changes in the adrenal gland cortex after induction of hepatic ischemia-reperfusion injury in male albino rats: Light and electron microscopic study.

The adrenal gland is an important endocrine gland in the body that secrets the adrenal hormones. One of the important clinical issues is the hepatic ischemia-reperfusion (IR) injury. Liver IR injury results in many distant organs dysfunctions such as lung, kidney, intestine, pancreas, and myocardium. The aim of the present study was to investigate the possible remote effects of hepatic IR on the structure of the adrenal cortex. Twenty healthy males, Sprague-Dawley albino rats aged 6-8 weeks were randomly divided into two groups (10 rats each): the sham control group (SC-group) and the ischemia-reperfusion group (IR-group). Sera were estimated for the following: aspartate transaminase (AST), alanine transaminase (ALT), lactic dehydrogenase (LDH), and corticosterone levels. Also oxidative markers such as malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α), and the antioxidative enzyme, catalase were measured. Adrenal glands were processed for light and transmission electron microscopic study. The results showed a significant increase in serum liver enzymes (AST, ALT, and LDH), corticosterone, MDA, and TNF-α levels and a significant decrease in serum levels of catalase in IR-group compared with SC-group. Adrenal cortical tissue of IR-group showed the loss of normal appearance. Some cells of zona glomerulosa and most of the zona fasciculata cells appeared swollen and degenerated with highly vacuolated cytoplasm. Other cells were shrunken with deeply acidophilic cytoplasm and pyknotic nuclei. Degenerated mitochondria with disrupted cristae, lipid droplets were confluent and dilated smooth endoplasmic reticulum were seen. Few zona reticularis cells had the dark nucleus and cytoplasmic vacuolations. In the different zones, blood capillaries were markedly congested and some inflammatory cells infiltrations were observed. Liver IR affected the structure of the adrenal cortex.

Diosgenin-caused changes of the adrenal gland histological parameters in a rat model of the menopause

Diosgenin, a steroidal sapogenin of natural origin, has demonstrated benefits when it comes to the treatment of malignancies, cardiovascular issues and menopausal symptoms. In this study, we investigated the histological changes of the adrenal gland after diosgenin application in a rat model of the menopause. Middle-aged, acyclic female Wistar rats were divided into control (C; n=6) and diosgenin treated (D; n=6) groups. Diosgenin (100mg/kg b.w./day) was orally administered for four weeks, while C group received the vehicle alone. A histological approach included design-based stereology, histochemistry and immunohistochemistry. The adrenal cortex volume decreased in D females by 15% (p<0.05) while the volume of adrenal medulla increased (p<0.05) by 64%, compared to the same parameters in C group. Volume density of the zona glomerulosa (expressed per absolute adrenal gland volume) in D rats increased (p<0.05) by 22% in comparison with C animals. Diosgenin treatment decreased (p<0.05) the volume density of the zona fasciculata (expressed per volume of adrenal cortex) by 15% when compared to C females. Absolute volume of the zona reticularis in D group decreased (p<0.05) by 38% in comparison with the same parameter in C rats. Also, after diosgenin application, the volume density of the zona reticularis (expressed per volume of adrenal cortex) and the zona reticularis cell volume were decreased by 51% and 20% (p<0.05) respectively, compared to C animals. Our results, reflecting a decrease in many stereological parameters of the adrenal cortex, indicate that diosgenin took over the role of corticosteroid precursors and became incorporated into steroidogenesis.

The morphology of the adrenal gland in the European bison (Bison bonasus).

BackgroundThe anatomy of the adrenal glands has been widely studied in many species of domestic and wild mammals. However, there are no available literature reports describing the morphology and morphometry of the adrenal glands of the European bison (Bison bonasus).ResultsThe study was conducted on 97 European bison of both sexes. The growth of the adrenal glands corresponded to the growth of the whole body, with the largest increase in size occurring in the first 2 years of the animal’s life, followed by a slower increase in size until the animal was 5–7 years old. There were no statistically significant differences between ipsilateral adrenal glands of males and females with respect to age. There was no statistically significant difference in weight between the left and the right adrenal gland. However, there was a difference in the length, width and thickness of the two glands. Reference intervals for adrenal gland size and weight were computed separately for two bison age groups (up to 2 years of age and older than two years). The adrenal gland consisted of a cortex and a medulla. The connective-tissue capsule contained two layers. It had a fibrous structure and abundant adipose tissue. The cortex was divided into three zones. The zona glomerulosa contained cells arranged in bundles and curves. Numerous apoptotic cells were observed among regular cells in the zona reticularis. There were vacuoles in the cells of both zona fasciculata and zona reticularis, which formed a foamy cytoplasm. The adrenal medulla was composed of large, dark cells with a highly basophilic cytoplasm in the superficial region and of smaller, lighter cells in deeper layers. Sinusoidal vessels were located in the central part of the medulla.ConclusionsThe left adrenal gland was significantly longer, narrower and thinner than the right one. There were no significant differences in the structure of the adrenal medulla and cortex of the European bison compared to other species of domestic and wild mammals. There was a thick layer of adipose cells at numerous locations in the adrenal capsule of the bison.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0783-8) contains supplementary material, which is available to authorized users.

Interleukin-6 inhibits adrenal androgen release from bovine adrenal zona reticularis cells by inhibiting the expression of steroidogenic proteins

Interleukin-6 (IL-6) is secreted by adrenocortical cells and modifies cortisol secretion. In this study, the effects of IL-6 on adrenal androgen release were investigated. The zona reticularis (ZR) was generally isolated from bovine adrenal glands by dissection. In select experiments, the intact adrenal cortex (ie, all 3 adrenocortical zones) was dissected from the adrenal glands. For androgen release experiments, ZR and intact adrenocortical cubes were dispersed into isolated cells, the cells cultured and exposed to IL-6 and/or adrenocorticotropic hormone (ACTH), and androgen release determined by radioimmunoassay. Basal and ACTH-stimulated androgen release from the ZR was inhibited by IL-6 in a concentration-dependent (10–1000 pg/mL) and time-dependent (4–24 h) manner (P < 0.01 by 1-way analysis of variance and the Bonferroni test). In contrast, IL-6 increased basal and ACTH-stimulated androgen release from mixed adrenocortical cells (P < 0.01). The mechanism of IL-6 inhibition of androgen release was investigated by exposing ZR strips to IL-6 and measuring the expression of the messenger RNA (mRNA) and protein of steroidogenic factors. Basal and ACTH-stimulated expression of the mRNA and protein for steroidogenic acute regulatory protein, cholesterol side chain cleavage enzyme, 3-β-hydroxysteroid dehydrogenase type 2, steroid 17-α-hydroxylase/17,20 lyase/17,20 desmolase, and the nuclear factor steroidogenic factor 1 (SF-1), that stimulates steroidogenesis, were decreased by IL-6 (P < 0.01). In contrast IL-6 increased the mRNA and protein for dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1), a nuclear factor that inhibits steroidogenesis (P < 0.01). In summary, IL-6 decreased androgen release and the expression of steroidogenic factors in the ZR, and this decrease may be mediated in part through increasing DAX-1 and decreasing SF-1.

Histomorphometrical and Electron Microscopic Study of Adrenocorticocytes Following Surgically Induced Extrahepatic Biliary Obstruction in Adult Female Albino Rats

Cholestasis, which is a component of many liver diseases, is often associated with symptoms that resemble clinical adrenal insufficiency. This work aimed to study the histomorphometrical and electron microscopic structure of adrenocorticocytes after surgical induction of bile duct resection (BDR) in adult female albino rats. Sixty rats were randomly divided into control, BDR and sham-operated groups. Six weeks after surgery, the blood serum of the rats was examined biochemically, and the suprarenal cortexes were prepared for histological, morphometrical and statistical studies. The BDR group showed a highly significant increase in bilirubin and serum alkaline phosphatase levels, whereas aldosterone and cortisol levels were highly significantly decreased. The area percentages of positive immunoreactions for P53, cyclooxygenase II (COX-II) and inducible nitric oxide synthase (INOS) revealed highly significant increases in the BDR group. Electron microscopic examination of the BDR group showed marked cytoplasmic vacuolations, large lipid droplets, swollen mitochondria and many small dark nuclei in the adrenocorticocytes. The zona fasciculata had heterogeneously electron-dense mitochondria and dilated smooth endoplasmic reticulum. Some of the zona reticularis cells contained lipofuscin pigments. The surgical induction of BDR produced deleterious effects on the structure and function of the adrenocorticocytes. A long-term study using different animal species is recommended for further examination.

English

The Indian wild caught bat, Taphozous kachhensis at Ambai Nimbai (Maharashtra) shows continuous asynchronous breeding, exhibiting a seasonal polyoestry. The adrenal gland of T. kachhensis is made up of adrenocortical and chromaffin tissues. The adrenocortical tissue is comprised of two main types of cells, the steroid cells with abundance of lipid inclusions and eosinophilic cells with eosinophilic granular cytoplasm. The chromaffin tissue is intermingled with adrenocortical tissue. They are formed of adrenaline and noradrenaline secreting cells with different electron density and variable sizes. The zona glomerulosa during estrus shows spherical nuclei with prominent nucleoli. Adrenal gland of pregnant female shows striking differences in ultrastructural features than those observed in the adrenal gland of non-pregnant female. During pregnancy, the cells of zona glomerulosa are hypertrophied and synthetically very active. The lysosomes and few lipid droplets are seen in cytoplasm of cell. The cells of zona fasciculata are large, vacuolated and arranged in cords of polygonal cells having mitochondria with tubular and lamellar cristae. The lipid droplets are observed in close association with smooth endoplasmic reticulum and mitochondria suggesting the role of these organelles in steroidogenesis. The cells of zona reticularis are loaded with lipid droplets. The mitochondria are spherical in shape with collapsed cristae. The cells of zona reticularis are in close association with blood vessels. Few lysosomal bodies are seen in the cytoplasm. Adrenal medulla consists of two types of cells depending on the presence of secretory granules. Nor-epinephrine cells are predominant in the medulla of pregnant bat while epinephrine cells are predominant in the medulla of estrus bat. Key words: Bat, adrenal gland, medulla, ultrastructure, reproductive cycle.

A histological study on the effect of noise on the adrenal cortex of adult male guinea pigs and the possible role of combined vitamins (A, C, and E) supplementation

Introduction Noise exposure is considered a stressful factor that causes changes in many organs, including the endocrine system. Timing of intervention by antioxidants obviously has a key role in the success of the therapeutic regimen. Aim of the work The aim of the study was to investigate the effect of noise exposure on the histological structure of the adrenal cortex in adult male guinea pigs and evaluate the role of postnoise treatment with vitamins A, C, and E. Materials and methods Thirty adult male guinea pigs were divided equally into three groups. Group I (the control group); group II (the experimental group), which was exposed to noise 4 h/day for 30 days; and group III, which was exposed to noise in the same manner as group II and then administered vitamins A, C, and E once daily for 5 successive days, starting 1 day after noise exposure. Specimens of the adrenal cortex were processed for study by light (H&E stain) and electron microscopy. Morphometric study was also performed. Results The adrenal cortex of the noise-exposed group (group II) showed loss of architecture of the zona glomerulosa and fasciculata with cellular infiltration. In addition, zona fasciculata cells showed marked cytoplasmic vacuolation, whereas zona reticularis cells appeared with condensed nuclei and congested blood sinusoids. Ultrastructurally, zona glomerulosa and fasciculata cells revealed swollen mitochondria, dilated cisternae of smooth endoplasmic reticulum, and a few lipid droplets. Animals treated with combined vitamins (group III) revealed restoration of the normal adrenocortical structure, whereas zona reticularis showed increased proliferative activity. Morphometric study revealed a significant increase in the mean thickness of the cortex and surface area of both zona glomerulosa and fasciculata of the exposed animals, whereas group III revealed nonsignificant difference from the control. Conclusion Exposure to noise caused histological alterations in the structure of the adrenal cortex. Postnoise treatment with vitamins A, C, and E could markedly reduce these alterations.

Pregnancy reduces the responsiveness of the pituitary–adrenal axis to dexamethasone

This study aimed to examine the influence of pregnancy on responsiveness of the pituitary–adrenal (PA) axis to dexamethasone (Dx) in rats. Dams and virgins were injected with Dx in three consecutive daily doses of 1.0, 0.5, 0.5mg/kg/bw, starting from day 16 of pregnancy, and sacrificed 24 and 72h after termination of treatment. Immunocytochemical, morphometrical and biochemical methods were used to assess pituitary and adrenal function. Three-way ANOVA revealed Dx inhibition of the PA axis in virgin and pregnant females after 24 and 72h. Pregnant females demonstrated a significantly lower (p<0.05) degree of suppression regarding ACTH volume density and blood concentrations and the volume and number of the zona fasciculata and zona reticularis cells, comparing with virgin females 72h following Dx administration, accompanied by total recovery of the zona glomerulosa. In contrast to virgin females, the corticosterone levels on day 21 of gestation reached control levels. Between days 19 and 21 of pregnancy, a significant increase in estrogen levels and the fall of progesterone influence, at least partially, the presented differences. It can be concluded that the PA axis response to the inhibitory influence of Dx is less pronounced in gravid females during late pregnancy than in virgin rats.

Differential expression of HSPA1 and HSPA2 proteins in human tissues; tissue microarray-based immunohistochemical study

In the present study we determined the expression pattern of HSPA1 and HSPA2 proteins in various normal human tissues by tissue-microarray based immunohistochemical analysis. Both proteins belong to the HSPA (HSP70) family of heat shock proteins. The HSPA2 is encoded by the gene originally defined as testis-specific, while HSPA1 is encoded by the stress-inducible genes (HSPA1A and HSPA1B). Our study revealed that both proteins are expressed only in some tissues from the 24 ones examined. HSPA2 was detected in adrenal gland, bronchus, cerebellum, cerebrum, colon, esophagus, kidney, skin, small intestine, stomach and testis, but not in adipose tissue, bladder, breast, cardiac muscle, diaphragm, liver, lung, lymph node, pancreas, prostate, skeletal muscle, spleen, thyroid. Expression of HSPA1 was detected in adrenal gland, bladder, breast, bronchus, cardiac muscle, esophagus, kidney, prostate, skin, but not in other tissues examined. Moreover, HSPA2 and HSPA1 proteins were found to be expressed in a cell-type-specific manner. The most pronounced cell-type expression pattern was found for HSPA2 protein. In the case of stratified squamous epithelia of the skin and esophagus, as well as in ciliated pseudostratified columnar epithelium lining respiratory tract, the HSPA2 positive cells were located in the basal layer. In the colon, small intestine and bronchus epithelia HSPA2 was detected in goblet cells. In adrenal gland cortex HSPA2 expression was limited to cells of zona reticularis. The presented results clearly show that certain human tissues constitutively express varying levels of HSPA1 and HSPA2 proteins in a highly differentiated way. Thus, our study can help designing experimental models suitable for cell- and tissue-type-specific functional differences between HSPA2 and HSPA1 proteins in human tissues.Electronic supplementary materialThe online version of this article (doi:10.1007/s00418-011-0791-5) contains supplementary material, which is available to authorized users.

Histological Structure of the Adrenal Gland of the Bottlenose Dolphin (Tursiops truncatus) and the Striped Dolphin (Stenella coeruleoalba) from the Adriatic Sea

The structure of the adrenal gland was studied in 11 bottlenose dolphins (Tursiops truncatus), and five striped dolphins (Stenella coeruleoalba). These species are legally protected in Croatia. All examined animals died of natural causes and were found stranded along eastern Adriatic coast. In both species the adrenal gland consists of a cortex and a medulla; the cortex is divided into three zones. Whereas in the bottlenose dolphin, there is a zona arcuata which contains columnar cells arranged in the form of arches; in the striped dolphin this zone is replaced by zona glomerulosa containing rounded clusters of polygonal cells. In both species, the zona fasciculata consists of radially oriented cords of polygonal cells, whereas in zona reticularis cells are arranged in branching and anastomosing cords. The adrenal medulla in both species contains dark, epinephrine-secreting cells and light norepinephrine-secreting cells. Epinephrine-secreting cells are localized in the outer part of the medulla, whereas norepinephrine-secreting cells are found in the inner part, arranged in clusters and surrounded by septa of thin connective tissue. The gland is surrounded by a thick connective-tissue capsule, from where thick trabeculae extend towards the interior. In the bottlenose dolphin, group of cells resembling both medullar and cortical cells can be seen within the capsule; whereas only groups of cells resembling cortical cells are found within the capsule of the striped dolphin. In the bottlenose dolphin invagination of the adrenal cortex into the medulla is obvious as well as medullary protrusions extending through cortex to the connective tissue capsule.

Heterogeneous levels of oxidative phosphorylation enzymes in rat adrenal glands

Mitochondria are organelles that produce ATP and reactive oxygen species, which are thought to be responsible for a decline in physiological function with aging. In this study, we morphologically and biochemically examined mitochondria in the rat adrenal gland. Immunohistochemistry showed that the rank order for intensity of immunolabelling for complex IV was zona reticularis > zona fasciculata ⪢ adrenal medulla, whereas for complex V α and β subunits, it was zona fasciculata > zona reticularis and adrenal medulla. The immunolabelling for complex I was homogeneous in the adrenal gland. The difference in immunolabelling between complexes I and IV indicates that the ratio of levels of complex I to that of complex IV in the zona reticularis was smaller than that in the zona fasciculata and the adrenal medulla. Electron microscopy revealed that aging rats had zona reticularis cells with many lysosomes and irregular nuclei. The result suggests that the level of proteins involved in oxidative phosphorylation is coordinated within the complex, but differs between the complexes. This might be responsible for degeneration of zona reticularis cells with aging.

Sex differences in adrenocortical structure and function. XXI. The effects of gonadectomy and testosterone or estradiol replacement on mitotic activity of the rat adrenal cortex.

The study was designed to investigate the mitotic activity of adrenal cortex in the adult male and female rats and to explain the effects of gonadal hormones on proliferation of rat adrenocortical cells. Mitotic index in individual zones of the adrenal cortex as well as a total number of mitoses on the "equatorial" sections of the gland were estimated in dexamethasone and colchicine pretreated control, gonadectomized and gonadectomized-gonadal hormone replaced rats. If compared with males, mitotic index of the zona reticularis (ZR) cells was higher in females, however, there was no difference in the remaining zones of the cortex. Neither orchiectomy nor testosterone had an effect on mitotic index of the zona glomerulosa (ZG) and zona fasciculata (ZF) cells. In the ZR, orchiectomy increased this index, an effect reversed by testosterone. Neither ovariectomy nor estradiol administration had an effect on mitotic index of the ZG and ZF, while in the ZR estradiol lowered this index if compared with control and gonadectomized rats. Total number of mitoses per "equatorial" section of the gland was similar in male and female rats. Orchiectomy increased this value, an effect reversed by testosterone. On the other hand, neither ovariectomy nor estradiol had an effect on the total number of mitoses per section of the adrenal gland.

Evaluation of Ki-67 antigen expression in the zona reticularis of the adrenal cortex of female rats in persistent estrus

Hyperandrogenism and chronic anovulation are basic characteristics of polycystic ovary syndrome (PCOS), and androgens from the adrenal glands play an important role in the hyperandrogenism. Our aim was to evaluate the proliferative activity in the zona reticularis cells of the adrenal cortex of female rats in persistent estrus, a model developed to mimic PCOS. Forty-four female Wistar-Hannover rats were randomly divided into two groups: control (n = 17) and animals which received 1.25 mg testosterone propionate s.c. on the second day of life (n = 27). At 90 days of age, after confirmation of persistent estrus, the animals were sacrificed, and the adrenal glands were removed and fixed in 10% buffered formalin to investigate Ki-67 antigen (marker of proliferation) expression by immunohistochemical analysis. Student's t-test and Levene's test were used in the statistical analysis. The mean percentage of Ki-67-stained nuclei per 1000 cells in the zona reticularis of the adrenal cortex was 15.58 +/- 1.14 (SEM) and 51.59 +/- 1.81 in the control and persistent estrus animals, respectively (P < 0.001). Proliferative activity in the zona reticularis cells of the adrenal cortex of the androgenized female rats was significantly greater than that of the control animals.