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  • 1
    Electronic Resource
    Electronic Resource
    Investigations on turnover of adrenocortical mitochondria (1974)
    Springer
    Cell & tissue research 151 (1974), S. 281-292 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Mitochondria ; ACTH ; DNA-synthesis ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a chronic ACTH administration (up to 12 consecutive days) on the 3H-thymidine uptake by the mitochondrial compartment of rat adrenal zona fasciculata were investigated by high resolution autoradiography, and compared with the changes in volume and number per cell of these organelles induced by the hormonal treatment. Up to the 9th day of treatment there is a significant increase in the tracer incorporation into adrenocortical mitochondria which is coupled with a significant increase in the volume of the organelles. After 12 days of hormone administration a significant decrease in the 3H-thymidine mitochondrial uptake is found, which is associated with a conspicuous increase in the number of mitochondria per cell and a net decrease in their average volume. The data are discussed in the light of evidence indicating that mitochondria possess a genetic apparatus largely independent of nuclear control. It is hypothesized that ACTH controls the growth and proliferation of adrenocortical mitochondria and that the mechanism of this action of ACTH involves stimulation of the mitochondrial DNA synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224539
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  • 2
    Electronic Resource
    Electronic Resource
    Investigations on adrenocortical mitochondria turnover (1974)
    Springer
    Cell & tissue research 150 (1974), S. 79-94 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Mitochondria ; ACTH ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a chronic administration of ACTH (up to 36 consecutive days) on the mitochondria of the zona fasciculata of the rat adrenal cortex were investigated by stereologic techniques. It was found that, while the volume of the mitochondrial compartment significantly increases in relation to the duration of treatment, the size and number of mitochondria display a different pattern. Up to the 9th day of hormone treatment mitochondria significantly increase in volume, whereas their number per cell is only slightly increased. After 12 days of ACTH-treatment there is a tremendous increase in the number of organelles per cell, resulting in a significant decrease in their average volume. After 24 and 36 consecutive days of treatment the number of mitochondria per cell as well as their average volume both show a slight but significantly constant increase. The hypothesis that ACTH controls the processes of growth and division of adrenal mitochondria is discussed in the light of evidence indicating that mitochondria contain a complete genetic apparatus largely independent of nuclear control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220382
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  • 3
    Electronic Resource
    Electronic Resource
    Stereological and functional investigations on isolated adrenocortical cells: Zona fasciculata/reticularis cells of chronically ACTH-treated rats (1989)
    Springer
    Cell & tissue research 258 (1989), S. 43-51 
    Details
    ISSN: 1432-0878
    Keywords: Isolated adrenocortical cells ; ACTH ; Steroidogenesis ; Stereology ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology and function of isolated inner (zona fasciculata/reticularis) adrenocortical cells of rats pretreated with ACTH for 3, 6, 9 or 12 days were investigated. ACTH treatment induced a notable time-dependent enhancement in the steroidogenic capacity (corticosterone production) and growth of inner cells. The volumes of cells, mitochondrial compartment, membrane space [the cellular space occupied by smooth endoplasmic reticulum (SER) membranes] and lipid-droplet compartment, as well as the surface area of mitochondrial cristae and SER tubules, were increased in relation to the duration of ACTH pretreatment, and showed a highly significant positive linear correlation with both basal and stimulated corticosterone production. The acute exposure of isolated cells to ACTH provoked a striking lipid-droplet depletion, the extent of which was linearly and positively correlated with stimulated corticosterone secretion. The hypertrophy of the mitochondrial compartment and SER are interpreted as the morphological counterpart of the enhanced steroidogenic capacity of inner adrenocortical cells, inasmuch as the enzymes of steroid synthesis are located in these two organelles, and it is well known that chronic ACTH exposure stimulates the de novo synthesis of many of them in vivo. The rise in the number of lipid droplets, in which cholesterol is stored, is interpreted as being due to the fact that, under chronic ACTH treatment, the processes leading to cholesterol accumulation in adrenocortical cells (exogenous uptake and endogenous synthesis) exceed those of its utilization in basal steroid secretion. Cholesterol accumulated in lipid droplets as a reserve material may be rapidly utilized after acute ACTH exposure to meet the needs of the enhanced steroidogenic capacity of adrenocortical cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223143
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  • 4
    Electronic Resource
    Electronic Resource
    Correlated morphometric and autoradiographic studies of the effects of corticosterone on adrenocortical cells of intact and hypophysectomized ACTH-treated rats (1970)
    Springer
    Cell & tissue research 111 (1970), S. 90-105 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Corticosterone ; Autoradiography ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of corticosterone on adrenocortical cells of intact and hypophysectomized ACTH-treated rats were investigated by morphometric and autoradiographic methods. The data obtained in these experiments allow us to make the following conclusions: 1 The most important morphological parameter for assessing the activity of a steroid-secreting cell is the quantity of smooth endoplasmic reticulum. 2 The decrement in the smooth reticulum in adrenocortical cells of rats treated with corticosterone is due to an inhibition of the protein synthesis by the hormones themselves. 3 There is in vivo a direct negative feed-back control mechanism at the adrenal level, mediated by an inhibition of the RNA synthesis by the corticosteroid-hormones. 4 The trophism of the mitochondrial fraction of adrenocortical cells is controlled by ACTH. It is possible to hypothesize that ACTH intervenes in the regulation of the mitochondrial RNA and DNA synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00342103
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  • 5
    Electronic Resource
    Electronic Resource
    Effects of a prolonged treatment with aminoglutethimide on the zona fasciculata of rat adrenal cortex: A morphometric investigation (1987)
    Springer
    Cell & tissue research 248 (1987), S. 519-525 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Aminoglutethimide ; Corticosterone ; Morphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a 7-day administration of aminoglutethimide (AG) on the adrenal zona fasciculata were examined in “normal” and dexamethasone/ACTH-treated rats. There was a 70–74% decrease in the concentration of corticosterone in blood, but no conspicuous qualitative changes suggesting cell degeneration occurred. Morphometry showed that AG induced a significant hypertrophy of the zona fasciculata and its parenchymal cells only in “normal” animals, which was due to an increase in the volume of the mitochondrial compartment and to proliferation of the smooth endoplasmic reticulum. This response to AG was considered to be non-specific and mediated by the enhanced secretion of ACTH following the decrease in the blood level of corticosterone. AG administration significantly increased the volume of the lipid-droplet compartment and the number of intramitochondrial lipid-like inclusions in both groups of animals. These changes were interpreted as the morphological counterpart of the AG-induced block of cholesterol utilization in steroid synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216478
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  • 6
    Electronic Resource
    Electronic Resource
    Short- and long-term effects of ACTH on the adrenal zona glomerulosa of the rat (1986)
    Springer
    Cell & tissue research 243 (1986), S. 303-310 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; ACTH ; Steroidogenesis ; Aldosterone escape phenomenon ; Stereology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Short-term ACTH treatment provoked a decrease in volume of the lipid-droplet compartment in rat zona glomerulosa cells, and a rise in plasma and intracellular concentrations of corticosterone and aldosterone. It enhanced activities of 3β-hydroxysteroid dehydrogenase (3βHSD), 11β-hydroxylase (11βOH) and 18-hydroxylase (18OH). Long-term ACTH administration produced a hypertrophy of the zona glomerulosa and its parenchymal cells, a result of the increase in volume of the smooth endoplasmic reticulum and the mitochondrial compartment. The surface area per cell of mitochondrial inner membranes increased; the tubular cristae were transformed into a homogeneous population of vesicles. The plasma and intracellular concentrations of corticosterone further increased, whereas those of aldosterone fell below basal levels (the “aldosterone-escape” phenomenon). The activities of 3βHSD and 11βOH were enhanced, that of 180H decreased. Therefore, ACTH stimulates zona glomerulosa growth and transforms parenchymal elements into zona fasciculata celltypes. Cyanoketone nullified acute ACTH effects on plasma and intracellular concentrations of corticosterone and aldosterone, but did not affect the activities of 11βOH and 18OH. Chronic ACTH treatment produced similar results, although 18OH activity was not suppressed. The mechanism underlying the “aldosterone-escape” phenomenon may thus involve a rise in the intracellular concentration of corticosterone, caused by the enhanced synthesis and activation of 3βHSD and 11βOH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00251044
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  • 7
    Electronic Resource
    Electronic Resource
    Morphometric investigations into the mechanism of the compensatory hypertrophy of the rat adrenal zona fasciculata after unilateral adrenalectomy (1983)
    Springer
    Cell & tissue research 234 (1983), S. 573-578 
    Details
    ISSN: 1432-0878
    Keywords: Adrenalectomy ; Hypophysectomy ; Compensatory adrenal growth ; Rat ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Compensatory hypertrophy of the remaining gland in unilaterally adrenalectomized rats was investigated by morphometric techniques. It was observed that compensatory adrenal growth occurred in both dexamethasone-treated and hypophysectomized rats, receiving maintenance doses of ACTH. However, it was only half that found in intact animals. These results support the view that activation of the hypothalamo-hypophyseal axis is not the unique mechanism underlying adrenal compensatory hypertrophy in the rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218652
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  • 8
    Electronic Resource
    Electronic Resource
    Autoradiographic study of the incorporation of tritiated cholesterol into the zona reticularis of the rat adrenal cortex (1969)
    Springer
    Cell & tissue research 102 (1969), S. 205-213 
    Details
    ISSN: 1432-0878
    Keywords: Rats ; Radioautography ; Cholesterol-3H ; Steroids (biosynthesis) ; Adrenal glands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the zona reticularis of the rat adrenal cortex three types of cells are to be observed: light, dark, and very dark cells. A time study of the incorporation of cholesterol-3H into these elements has been made. The data obtained from autoradiographic study are discussed in relation to the hypothesis that the light cells are elements in active steroido-synthesis, the dark cells are resting elements, and the very dark cells are elements in degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335501
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  • 9
    Electronic Resource
    Electronic Resource
    Investigations into the mechanism of hormone release by rat adrenocortical cells (1978)
    Springer
    Cell & tissue research 189 (1978), S. 403-407 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal gland ; Rat ; Vinblastine ; Corticosterone ; Exocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vinblastine treatment blocks corticosterone release from rat adrenal zona fasciculata without impairing hormone synthesis, and induces the formation of acid phosphatase-positive granular clumps at the juxta-sinusoidal pole of the cells. Autoradiography shows that ACTH administration to vinblastine-treated animals mobilizes the 3H-cholesterol stored in the lipid droplets and leads to a noticeable labelling of the granular clumps. The possible significance of these granules is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209129
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  • 10
    Electronic Resource
    Electronic Resource
    Gestational changes in hamster adrenal cortex: Morphometric and ultrastructural stereologic studies (1989)
    Springer
    Cell & tissue research 256 (1989), S. 241-246 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Pregnancy ; Electron microscopy ; Stereology ; Golden hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the hamster, the weight of the adrenal glands increases during the course of gestation, with the highest value at day 5. In comparison to non-pregnant control animals, there were no changes in the volume of the zona glomerulosa (ZG) and zona fasciculata (ZF), while the volume of the zona reticularis (ZR) increased notably. The average volume of ZG-cells rose at day 5 of pregnancy and thereafter gradually decreased to that of control hamsters. A marked drop in the volume of ZF-cells was seen at days 5 and 10 of pregnancy, whereas at day 15 the cells were larger than in controls. At day 5 of pregnancy, a conspicuous increase in the cell volume was found in ZR, followed by lower values at day 10 and again higher than in control hamsters at day 15. The total number of parenchymal cells in hamster adrenal cortex increased at day 10 of gestation, then underwent a marked decrease, reaching the control value at the final day of pregnancy; this drop was mainly due to a reduction in the number of ZF-cells. The changes in the cell volume were paralleled by rather proportional changes in the volume of the mitochondrial compartment and in the quantity of smooth endoplasmic reticulum. The volume of the lipid-droplet compartment significantly rose in the course of gestation in both ZF- and ZR-cells. The cortisol output by adrenal homogenates gradually decreased during pregnancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218881
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