scholarly journals CYTOLOGICAL ALTERATIONS RELATED TO STIMULATION OF THE ZONA GLOMERULOSA OF THE ADRENAL GLAND

1965 ◽  
Vol 26 (2) ◽  
pp. 499-521 ◽  
Author(s):  
Filiberto Giacomelli ◽  
Joseph Wiener ◽  
David Spiro
Keyword(s):  
Endoplasmic Reticulum ◽  
Adrenal Gland ◽  
Light And Electron Microscopy ◽  
Zona Glomerulosa ◽  
High Electron ◽  
Dense Bodies ◽  
Large Numbers ◽  
Cytological Alterations ◽  
Parallel Arrays ◽  
Stimulation Of

The structure of the zona glomerulosa of the rat adrenal gland stimulated by sodium restriction has been studied by light and electron microscopy. The major changes observed during the course of the experiment in stimulated glands involve cytoplasmic droplets, mitochondria, and the endoplasmic reticulum. There is a progressive decrease in the number of cytoplasmic droplets of low electron opacity. Numerous, greatly elongated mitochondria containing parallel arrays of tubules are noted. These tubules extend from within the mitochondria through gaps in the mitochondrial-limiting membranes into the cytoplasm. In addition, amorphous intramitochondrial deposits, possibly aldosterone precursors, are seen. Increased amounts of smooth-surfaced endoplasmic reticulum, often showing complex arrangements, are another feature of the stimulated zona glomerulosa. Other alterations include the presence of large numbers of dense bodies as well as cytoplasmic droplets of high electron opacity. These observations are discussed in relation to the biosynthesis of aldosterone.

THE HISTOGENESIS OF THE ADRENAL CORTEX IN THE FOETAL SHEEP

1979 ◽  
Vol 91 (1) ◽  
pp. 134-149 ◽  
Author(s):  
Peter M. Robinson ◽  
Elisabeth J. Rowe ◽  
E. Marelyn Wintour
Keyword(s):  
Endoplasmic Reticulum ◽  
Steroid Hormones ◽  
Adrenal Glands ◽  
Smooth Endoplasmic Reticulum ◽  
Rapid Development ◽  
Light And Electron Microscopy ◽  
Cortical Cell ◽  
Outer Zone ◽  
Zona Glomerulosa ◽  
Zona Fasciculata

ABSTRACT The cortex of sheep foetal adrenal glands from 25 days gestation until newborn (term equals 147 ± 3 days) were examined by light and electron microscopy. Three stages of development are of particular importance in relating structure to function: 1) from 35 to 60 days, 2) from 60 to 120 days and 3) from 120 days to term. Between 35 and 60 days one cortical cell type predominated. It contained mitochondria with lamellar and vesicular cristae, scattered long strands of granular endoplasmic reticulum and only small amounts of smooth endoplasmic reticulum. After about 60 days two zones were apparent in the cortex and chromaffin cells became concentrated in the medulla. After 80 days the outer zone contained cells which resembled mature zona glomerulosa cells and the cells in the inner zone remained like those seen between 35 and 60 days, except they contained even less smooth endoplasmic reticulum. However, after about 90 days a small number of deep inner zone cells contained mitochondria with vesicular cristae which thus resemble mitochondria in the mature zona fasciculata. From about 120 days there was an increase in the number of cells in the inner zone that contained mitochondria with vesicular cristae. These cells also contained substantial quantities of smooth endoplasmic reticulum. At term most inner zone cells have this mature appearance. Thus there is no "foetal cortex" in the sheep analogous to that found in human adrenal development, i. e. there is no prominent zone of cells containing large amounts of smooth endoplasmic reticulum which is present throughout most of the foetal period of development, and which regresses at birth. The structure of the cells present between 35 and 60 days was unexpected because it has been shown previously that sheep foetal adrenals of this age are capable of producing relatively large quantities of steroid hormones. However, the appearance of cells resembling mature zona glomerulosa cells at about 80 days correlates with the previously demonstrated ability of sheep adrenal glands of this age to produce relatively large quantities of aldosterone. The rapid development of numbers of mature cells in the last 3 weeks of gestation correlates with the previously described ability of near term sheep foetal adrenals to produce very large quantities of steroid hormones.

Protoplasmic changes during stomatal development in Funaria

1983 ◽  
Vol 61 (10) ◽  
pp. 2515-2526 ◽  
Author(s):  
Fred D. Sack ◽  
D. J. Paolillo Jr.
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Density ◽  
Pore Formation ◽  
Light And Electron Microscopy ◽  
Polar Regions ◽  
Lipid Bodies ◽  
Stomatal Development ◽  
Funaria Hygrometrica ◽  
Parallel Arrays

Key protoplasmic features of stomatal development in Funaria hygrometrica Hedw. (Musci) were characterized using light and electron microscopy. Endoplasmic reticulum (ER) cisternae are initially rough and often arranged in parallel arrays. During pore formation, the cytoplasm becomes packed with tubular, smooth ER. Older but still functional stomata contain small amounts of primarily cisternal ER. Lipid bodies decrease in electron density when tubular ER appears. Preliminary observations indicate that two large vacuoles occupy the polar regions of open, but not closed, stomata. Intact plasmodesmata occur in developing but not mature walls. Plastid structure, microtubule distribution, and other protoplasmic features are essentially similar to those described in the stomata of other genera.

scholarly journals Effect of adrenomedullin infusion on basal and stimulated aldosterone secretion in conscious sheep with cervical adrenal autotransplants

2000 ◽  
Vol 166 (2) ◽  
pp. 389-399 ◽  
Author(s):  
R Salemi ◽  
JG McDougall ◽  
KJ Hardy ◽  
EM Wintour
Keyword(s):  
Adrenal Gland ◽  
Zona Glomerulosa ◽  
Cortisol Secretion ◽  
Aldosterone Secretion ◽  
Stimulation Experiments ◽  
Gland Function ◽  
Conscious Sheep ◽  
Stimulation Of

In vivo and in vitro studies have shown conflicting effects of adrenomedullin (ADM) on the secretion of steroid hormones from the adrenal gland. While some investigators report no effect of this peptide on the output of various hormones, others have reported both stimulatory and inhibitory roles for ADM. We have shown that basal aldosterone secretion rate (ASR), in conscious sheep with cervical adrenal autotransplants, did not change when ADM was infused directly into the adrenal arterial supply. While not affecting basal ASR, ADM did produce pronounced increases in adrenal blood flow (BF). This elevation of BF in association with ADM infusion was seen in all subsequent experiments. When aldosterone output was acutely stimulated by angiotensin II (AngII), potassium chloride (KCl) and adrenocorticotrophic hormone (ACTH), ADM was seen to drastically reduce the secretion of aldosterone with all agonists studied. After pre-exposure to ADM, all three agonists increased ASR but the magnitude of the responses were somewhat blunted. ADM did not have the same effect on cortisol secretion stimulated by ACTH, suggesting that the ability of this peptide to influence adrenal gland function is limited to the zona glomerulosa. In conditions of chronic elevation of aldosterone levels, such as in Na deficiency, ADM did not display the same inhibitory abilities seen in the acute stimulation experiments. Hence, ADM has been shown to have a direct, inhibitory role on the acute stimulation of aldosterone by AngII, KCl and ACTH while not affecting basal or chronic aldosterone secretion or cortisol secretion stimulated by ACTH.

scholarly journals STIMULATION OF GLUCOSE-6-PHOSPHATASE ACTIVITY IN THE MUCOSAL CELLS OF THE MOUSE INTESTINE

1973 ◽  
Vol 21 (5) ◽  
pp. 426-440 ◽  
Author(s):  
J. S. HUGON ◽  
D. MAESTRACCI ◽  
D. MÉNARD
Keyword(s):  
Endoplasmic Reticulum ◽  
Phosphatase Activity ◽  
Smooth Endoplasmic Reticulum ◽  
Male Mice ◽  
Dense Bodies ◽  
Absorptive Cells ◽  
Mucosal Cells ◽  
Mouse Intestine ◽  
Stimulation Of

Adult Swiss ICR male mice were fed fructose or glucose for several days. Glucose-6-phosphatase activity in the duodenal and jejunal epithelium was measured by biochemical and cytophotometric means, and it was also localized cytochemically. The fructose diet stimulated glucose-6-phosphatase activity within 6 hr of feeding. The enzyme was stimulated more in the absorptive cells of the basal third than in those of the median and apical third of the villi. After 3 days of feeding of fructose, the smooth endoplasmic reticulum hypertrophied and occupied large areas in the absorptive cells. Lipoprotein spherules and polymorphic dense bodies were also observed. No such modifications were seen in glucose-fed animals.

The Fine Structure Of Photoreceptors In Mitopus Morio (Phalangida)

1969 ◽  
Vol 4 (2) ◽  
pp. 327-351
Author(s):  
D. J. CURTIS
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membranes ◽  
Acetylcholinesterase Activity ◽  
Structural Studies ◽  
Hexagonal Array ◽  
Laminated Structure ◽  
Dense Bodies ◽  
Single Lens ◽  
Dioptric Apparatus ◽  
Stimulation Of

Fine structural studies on the eyes of the harvestman Mitopus morio revealed the presence of microvilli in the rhabdom. The microvilli vary in length between 1 µ and 2 µ, are about 800 Å wide, and curved or straight. They derive from the plasma membranes of the four retinula cells which surround the rhabdom. Approximately cylindrical in shape, the rhabdoms are about 40 µ long by about 4-6 µ in cross-diameter. Each rhabdom is situated at the centre of a retinula, and these retinulae are packed in a hexagonal array to form the retina. Distally, rhabdom fusion occurs to form a rhabdom network. The retina lies beneath the dioptric apparatus which consists of a single lens, surmounting a glassy body composed of lentigen cells. The cytoplasmic organelles of the retinula cells include mitochondria, lysosomes, sparse elements of endoplasmic reticulum, vesicular components, prominent Golgi complexes and pigment granules which possess a laminated structure. An important feature of the retinula cell is the presence of many small vesicles, about 0.1 µ in diameter, clustered beneath the rhabdom. Incubation of glutaraldehyde-fixed eyes in a Gomori medium with acetylthiocholine as substrate, coupled with inhibition of controls by 62C47, indicates the presence of a presumed acetylcholinesterase in these vesicles. Similar vesicles also occur in the proximal cytoplasm of the retinula cells. Other larger vesicles, often with a core of whorled membranes, as well as dense bodies, also show acetylthiocholine-splitting activity. This latter activity is not inhibited by 62C47 and is probably the effect of lysosomal non-specific esterase. These bodies also exhibit acid phosphatase activity when incubated in a Gomori medium with β-glycerophosphate as substrate. The presence of acetylcholinesterase activity, as distinct from non-specific esterase, in vesicles closely associated with the rhabdom and in more proximally situated vesicles is significant. It would point to the presence of an acetylcholine/acetylcholinesterase system involved in the generation and/or propagation of the sensory impulse arising from photo-stimulation of the rhabdom.

Copper Localization in Cirrhotic Rat Liver by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 38-39 ◽  
Author(s):  
J. C. Russ ◽  
E. McNatt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Copper Acetate ◽  
Lead Citrate ◽  
Dense Bodies ◽  
Transmission Electron ◽  
Electron Mode ◽  
Scanning Electron

In order to study the retention of copper in cirrhotic liver, rats were made cirrhotic by carbon tetrachloride inhalation twice weekly for three months and fed 0.2% copper acetate ad libidum in drinking water for one month. The liver tissue was fixed in osmium, sectioned approximately 2000 Å thick, and stained with lead citrate. The section was examined in a scanning electron microscope (JEOLCO JSM-2) in the transmission electron mode.Figure 1 shows a typical area that includes a red blood cell in a sinusoid, a disse, and a portion of the cytoplasm of a hepatocyte which contains several mitochondria, peribiliary dense bodies, glycogen granules, and endoplasmic reticulum.

Analysis of the Anterior Secretory Cells of Onchidohs Muricata (Nudibranchia)

1981 ◽  
Vol 39 ◽  
pp. 614-615
Author(s):  
Roy Skidmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Golgi Body ◽  
The Body ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
High Magnification ◽  
Large Numbers ◽  
Membrane Bound ◽  
Sole Of The Foot

The long-necked secretory cells in Onchidoris muricata are distributed in the anterior sole of the foot. These cells are interspersed among ciliated columnar and conical cells as well as short-necked secretory gland cells. The long-necked cells contribute a significant amount of mucoid materials to the slime on which the nudibranch travels. The body of these cells is found in the subepidermal tissues. A long process extends across the basal lamina and in between cells of the epidermis to the surface of the foot. The secretory granules travel along the process and their contents are expelled by exocytosis at the foot surface.The contents of the cell body include the nucleus, some endoplasmic reticulum, and an extensive Golgi body with large numbers of secretory vesicles (Fig. 1). The secretory vesicles are membrane bound and contain a fibrillar matrix. At high magnification the similarity of the contents in the Golgi saccules and the secretory vesicles becomes apparent (Fig. 2).

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

scholarly journals STUDIES ON MICROPEROXISOMES II. A CYTOCHEMICAL METHOD FOR LIGHT AND ELECTRON MICROSCOPY

1972 ◽  
Vol 20 (12) ◽  
pp. 1006-1023 ◽  
Author(s):  
ALEX B. NOVIKOFF ◽  
PHYLLIS M. NOVIKOFF ◽  
CLEVELAND DAVIS ◽  
NELSON QUINTANA
Keyword(s):  
Endoplasmic Reticulum ◽  
Guinea Pig ◽  
Lipid Droplets ◽  
Smooth Endoplasmic Reticulum ◽  
Light And Electron Microscopy ◽  
Distal Tubule ◽  
Striking Difference ◽  
High Concentration ◽  
Electron Microscopic ◽  
Pig Kidney

A modification of the Novikoff-Goldfischer alkaline 3,3'-diaminobenzidine medium for visualizing peroxisomes is described. It makes possible light microscopic as well as electron microscopic studies of a recently described class of peroxisomes, the microperoxisomes. Potassium cyanide (5 x 10–3 M) is included in the medium to inhibit mitochondrial staining, the pH is 9.7 and there is a high concentration of H2O2 (0.05%). Two cell types have been chosen to illustrate the advantages of the new procedure for demonstrating the microperoxisomes: the absorptive cells in the human jejunum and the distal tubule cells in the guinea pig kidney. Suggestive relations of microperoxisomes and lipid are described in the human jejunum. The microperoxisomes are strategically located between smooth endoplasmic reticulum that radiates toward the organelles and contains lipid droplets and "central domains" of highly specialized endoplasmic reticulum which do not show the lipid droplets. The microperoxisomes are also present at the periphery of large lipid-like drops. In the guinea pig kidney tubule there is a striking difference between the thick limb of Henle and distal tubule. The distal tubule has a population of cells with large numbers of microperoxisomes readily visible by light microscopy; these cells are not present in the thick limb of Henle. Other differences between the two are also described.

Sign in / Sign up

Export Citation Format

Share Document