scholarly journals Microfilament-mediated surface change in starfish oocytes in response to 1-methyladenine: implications for identifying the pathway and receptor sites for maturation-inducing hormones.

1981 ◽  
Vol 90 (2) ◽  
pp. 362-371 ◽  
Author(s):  
T E Schroeder
Keyword(s):  
Follicle Cell ◽  
Early Response ◽  
Follicle Cells ◽  
Pisaster Ochraceus ◽  
Receptor Sites ◽  
Equivalent Number ◽  
Cell Processes ◽  
First Time ◽  
Stimulation Of

Oocytes of the starfish Pisaster ochraceus exhibit an early response to 1-methyladenine (the maturation-inducing hormone), which is described for the first time. In this response approximately 6,500 spikelike surface projections, much larger than microvilli, emerge transiently from oocytes stripped of their follicle cells and then treated with the hormone in vitro. Each spike contains a prominent bundle of microfilaments, possibly composed of actin. The distribution of spikes when follicle cells are only partially removed and the morphological details of the normal junctional association between follicle cells and oocytes suggest that 1-methyladenine-sensitive sites (receptor sites) can be identified with the approximately 6,500 postjunctional specializations that are part of the oocyte surface. This finding in turn is employed to construct a set of hypotheses concerning the route that 1-methyladenine normally takes from the follicle cells to an oocyte during stimulation of maturation; it is postulated that, for each oocyte, 1-methyladenine is transported along approximately 6,500 thin follicle-cell processes, it is transmitted across the junctional gaps of an equivalent number of junctions between follicle cells and an oocyte, and then interacts with the postjunctional sites where 1-methyladenine receptors are thought to be clustered. Comparative aspects of this mode of intercellular communication are discussed.

TREATMENT OF MUCOCUTANEOUS CANDIDIASIS WITH TRANSFER FACTOR

PEDIATRICS ◽  
1974 ◽  
Vol 53 (1) ◽  
pp. 63-70
Author(s):  
Ralph D. Feigin ◽  
Penelope G. Shackelford ◽  
Seth Eisen ◽  
Lynn E. Spitler ◽  
Larry K. Pickering ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Skin Test ◽  
Migration Inhibitory Factor ◽  
Transfer Factor ◽  
Chronic Mucocutaneous Candidiasis ◽  
Myeloperoxidase Activity ◽  
Mucocutaneous Candidiasis ◽  
Receptor Sites ◽  
Stimulation Of

Evaluation of a patient with chronic mucocutaneous candidiasis revealed that the patient lacked delayed hypersensitivity to candida and other skin test antigens and the patient's lymphocytes could not be stimulated in vitro with candida antigen. Phytohemagglutinin stimulation of lymphocytes in vitro was normal. Candidacidal function and myeloperoxidase activity of the patient's leukocytes were normal. The patient's lymphocytes produced migration inhibitory factor in response to candida antigen and the monocyte receptor sites for IgG were intact. Repeated treatments with amphotericin B, alone or with 5-fluorocytosine, were followed by immediate relapse. Four doses of transfer factor were administered and when coupled with amphotericin B on two occasions prompted remissions of 6 and 4 months, respectively.

scholarly journals STEROID INHIBITION OF PROTEIN INCORPORATION BY ISOLATED AMPHIBIAN OOCYTES

1974 ◽  
Vol 61 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Allen W. Schuetz ◽  
Robin A. Wallace ◽  
James N. Dumont
Keyword(s):  
Rana Pipiens ◽  
Follicle Cells ◽  
Blood Protein ◽  
Short Treatment ◽  
Nuclear Maturation ◽  
Desoxycorticosterone Acetate ◽  
Protein Incorporation ◽  
The Relationship ◽  
Stimulation Of

The relationship between blood protein (vitellogenin) incorporation and nuclear maturation was studied in individual amphibian oocytes after in vitro exposure to desoxycorticosterone acetate (DOCA). Isolated Rana pipiens oocytes were incubated in vitro with radioactively labeled oocyte yolk precursor ([3H]vitellogenin) obtained from estrogenized Xenopus laevis. Incorporation of labeled vitellogenin into the oocytes continued over a 24-h period. Oocytes simultaneously exposed to DOCA and to labeled vitellogenin exhibited both inhibition of vitellogenin incorporation and stimulation of nuclear maturation and cortical changes. Inhibition of vitellogenin incorporation was observed after approximately 9 h of incubation and was correlated with the time of nuclear breakdown. Preincubation of oocytes in steroid for 9 h essentially terminated vitellogenin incorporation. Incorporation of vitellogenin occurred after removal of follicle cells from the oocyte by a short treatment with EDTA. These results demonstrate the macromolecular vitellogenin transport system remains operative in oocytes which can undergo nuclear maturation and that the steroid DOCA can affect its function. Evidence suggests that the mechanism of steroid inhibition is in part the result of inhibition of the micropinocytotic process in the oocyte cortex.

The stimulation of sodium transport by aldosterone

1971 ◽  
Vol 262 (842) ◽  
pp. 323-332 ◽  
Keyword(s):  
Protein Synthesis ◽  
Active Transport ◽  
Sodium Transport ◽  
Apical Plasma Membrane ◽  
Transport Pathway ◽  
Receptor Sites ◽  
Rna And Protein Synthesis ◽  
Inhibitor Of Protein Synthesis ◽  
Stimulation Of

Aldosterone, the major sodium retaining hormone in man, will stimulate active transport of sodium across the urinary bladder of the toad, Bufo marinus in vitro , at physiological concentrations of the hormone.The in vitro action of aldosterone is mimicked by steroid hormones with known mineralocorticoid properties and it is competitively inhibited by other analogues, e.g. spironolactone and cortisone. Aldosterone is bound to physiological receptor sites within the transporting epithelial cells, chiefly within the nuclei, and is displaced from these binding sites specifically by structural analogues including other mineralocorticoids. Effects of aldosterone are dependent upon availability of metabolizable substrates to support the active transport of sodium. Although the stimulation of sodium transport by aldosterone can be specifically inhibited by actinomycin D, an inhibitor of RNA synthesis, and by puromycin, an inhibitor of protein synthesis, direct evidence of stimulation of new RNA and protein synthesis during the latent period with physiological concentrations of aldosterone is still lacking. It is possible, however, that the amounts of RNA and protein that are involved are too small to be detected by available techniques. Evidence is summarized which leads us to conclude that the increased sodium transport induced by aldosterone is the consequence of a reduced resistance of the apical plasma membrane of the transporting epithelia to the entry of sodium into the transport pathway.

scholarly journals beta-Naphthoflavone abolishes interrenal sensitivity to ACTH stimulation in rainbow trout

1998 ◽  
Vol 157 (1) ◽  
pp. 63-70 ◽  
Author(s):  
JM Wilson ◽  
MM Vijayan ◽  
CJ Kennedy ◽  
GK Iwama ◽  
TW Moon
Keyword(s):  
Cytochrome P450 ◽  
Rainbow Trout ◽  
Acth Stimulation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Treated Fish ◽  
First Time ◽  
Hepatic Cytochrome ◽  
Stimulation Of

We report for the first time that beta-naphthoflavone (BNF) abolishes ACTH stimulation of cortisol production in rainbow trout (Oncorhynchus mykiss). There was significantly higher hepatic cytochrome P450 content and ethoxyresorufin O-de-ethylase and uridine-5'-diphosphoglucuronic acid transferase activities in BNF-treated fish than in sham-treated controls. BNF did not significantly affect either plasma turnover or tissue distribution of [3H]cortisol-derived radioactivity. Hepatic membrane fluidity and hepatocyte capacity for cortisol uptake were not altered by BNF as compared with the sham-treated fish. These results taken together suggest that BNF does not affect cortisol-clearance mechanisms in trout. A 3 min handling disturbance period elicited a plasma cortisol response in the sham-treated fish; however, the response in the BNF-treated fish was muted and significantly lower than in the sham fish. This in vivo response corroborates the lack of interrenal sensitivity to ACTH in vitro in the BNF-treated fish, suggesting that BNF affects the ACTH pathway in trout. Our results suggest the possibility that cytochrome P450-inducing compounds may affect cortisol dynamics by decreasing interrenal responsiveness to ACTH stimulation in fish, thereby impairing the physiological responses that are necessary for the animal to cope with the stressor.

UPTAKE OF ALDOSTERONE BY HUMAN SKIN AND STIMULATION OF RNA SYNTHESIS IN THE SWEAT GLAND IN VITRO

1969 ◽  
Vol 45 (2) ◽  
pp. 231-NP ◽  
Author(s):  
K. DIXON ◽  
V. SCHWARZ
Keyword(s):  
Human Skin ◽  
Sweat Gland ◽  
Rna Synthesis ◽  
Sweat Duct ◽  
Large Excess ◽  
Receptor Sites ◽  
Presence And Absence ◽  
Stimulation Of

SUMMARY Autoradiography of human skin, after incubation with tritiated aldosterone or pregnenolone, showed both steroids to be concentrated in all types of cells. Binding of [3H]aldosterone in skin was investigated in the presence and absence of a large excess of unlabelled hormone. The capacity of the cells to bind aldosterone in a manner suggesting attachment to receptor sites was estimated to be 5 × 10-13 moles/g. The rate of RNA synthesis was measured in the various cells of the sweat gland: it was shown to be significantly increased by aldosterone. This stimulation was observed in the inner and outer cells of the sweat duct and probably also in the secretory tubule.

A gonadotrophin-releasing hormone (GnRH) antagonist inhibits GnRH- but not LH-induced meiosis in follicle-enclosed rat oocytes in vitro

1982 ◽  
Vol 101 (2) ◽  
pp. 264-267 ◽  
Author(s):  
C. Ekholm ◽  
T. Hillensjö ◽  
W. J. Le Maire ◽  
C. Magnusson ◽  
C. S. Sheela Rani
Keyword(s):  
Gnrh Agonist ◽  
Gnrh Antagonist ◽  
Similar Response ◽  
Releasing Hormone ◽  
Lactate Accumulation ◽  
Receptor Sites ◽  
Gonadotrophin Releasing Hormone ◽  
Stimulation Of

Abstract. Previous studies have shown that gonadotrophin-releasing hormone (GnRH) can induce resumption of meiosis in follicle-enclosed rat oocytes. In the present study a GnRH antagonistic analogue ([d-pGlul, d-Phe2,-d-Trp3,6]LRF) was found to effectively abolish the stimulatory effect of a GnRH agonist upon resumption of meiosis and lactate accumulation in isolated pre-ovulatory rat follicles but the have no effect on LH stimulation of these parameters. It is concluded that although LH and GnRH can evoke a similar response they act through separate receptor sites and that it is unlikely that GnRH mediates the effect of LH on meiosis or glycolysis.

Extrafollicular mediation of oocyte maturation by radial nerve factor in starfish Pisaster ochraceus

Zygote ◽  
2000 ◽  
Vol 8 (4) ◽  
pp. 359-368 ◽  
Author(s):  
Allen W. Schuetz
Keyword(s):  
Oocyte Maturation ◽  
Radial Nerve ◽  
Actinomycin D ◽  
Ovarian Tissue ◽  
Germinal Vesicle ◽  
Follicle Cells ◽  
Pisaster Ochraceus ◽  
Ovarian Wall

In starfish ovaries follicle cells that envelop each oocyte are thought to mediate the production of a maturation inducing substance (MIS), identified as 1-methyladenine, that induces maturation and spawning of oocytes after exposure to a gonadotropic substance secreted by the radial nerve (RNF). Studies were carried out to assess the possible role of extrafollicular cells within the ovarian wall in mediating this signal transduction process in the ovary of Pisaster ochraceus. Oocyte maturation and spawning occurred following the addition of RNF to intact ovarian tissue in vitro whereas no maturation occurred following the addition of RNF to germinal vesicle (GV) oocytes or GV oocytes surrounded by follicle cells. In contrast, oocyte maturation occurred when small ovarian wall fragments, lacking mature follicles, were incubated with GV oocytes and RNF. Neither actinomycin D nor cycloheximide altered RNF induction of oocyte maturation in the presence of the ovarian wall tissue whereas preheating (boiling water for 5 min) the tissue obliterated its response to RNF. Non-ovarian tissues failed to produce MIS in response to RNF. Results suggest that ovarian components other than the follicle cells that envelop fully grown immature oocyte are responsive to RNF and represent a significant and previously unrecognised intra-ovarian source of MIS.

Culture Techniques and Potential Research Applications of Human Hair Follicle Cells In Vitro

1985 ◽  
Vol 13 (1) ◽  
pp. 8-37
Author(s):  
A.J.M. Vermorken
Keyword(s):  
Epithelial Cells ◽  
Hair Follicle ◽  
Human Hair ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Human Hair Follicle ◽  
Culture Techniques ◽  
Ready Availability ◽  
Skin Biopsies

Since 1980, when human hair follicle cells were cultured in vitro for the first time, a whole series of techniques have been developed that render hair follicle keratinocytes as easy to handle in culture as fibroblasts. As a consequence, one can conclude that the need for a method providing for the routine cultivation of easily obtainable human primary epithelial cells has now been met, and it may be expected that more and more workers will use hair follicle keratinocytes for studies that specifically require human epithelial cells. The ease of culture and the ready availability of material may encourage workers to consider human hair follicle cell culture before either animal models or cultures of cells derived from invasive skin biopsies.

scholarly journals Distribution of yolk polypeptides in the follicle cells during the differentiation of the follicular epithelium in Sarcophaga bullata egg follicles

Development ◽  
1987 ◽  
Vol 101 (1) ◽  
pp. 33-43
Author(s):  
J. Geysen ◽  
J. Cardoen ◽  
A. De Loof
Keyword(s):  
Rna Synthesis ◽  
Follicle Cell ◽  
In Vitro Translation ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Current Pattern ◽  
Sarcophaga Bullata ◽  
Polypeptide Synthesis ◽  
Egg Follicles

In S. bullata, the ovaries contribute to the synthesis of yolk polypeptides. A specific antiserum for yolk polypeptides was used to visualize the presence of yolk polypeptides in the follicle cells during their differentiation. After vitellogenesis has started, all follicle cells contain yolk polypeptides. The squamous follicle cells covering the nurse cells and the border cells lose yolk polypeptides before mid-vitellogenesis, whereas the follicle cells over the oocyte contain yolk polypeptides until after late vitellogenesis. All follicle cells are immunonegative afterwards. In vitro translation of poly(A)+ RNA demonstrated that the presence of yolk polypeptide mRNA correlates well with follicle cell immunopositivity for yolk polypeptides. This suggests that the follicle cells synthesize the ovarian yolk polypeptides. Differences in cellular and nuclear morphology, total and poly(A)+ RNA synthesis and the rate of yolk polypeptide synthesis were shown to be correlated with the presence or absence of yolk polypeptides in the differentiating follicular epithelium. The possible relationship between these different aspects of follicle cell differentiation, follicle cell polyploidy and the extracellular current pattern around follicles are discussed.

The effect of androgen on wool follicles and keratin production in Hetian sheep

2021 ◽  
Vol 81 (3) ◽  
pp. 526-536
Author(s):  
H. Y. Wang ◽  
S. W. Li ◽  
T. H. Wu ◽  
Z. H. Wu ◽  
J. X. Guo
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Cell Apoptosis ◽  
Follicle Cell ◽  
Gene Expression Level ◽  
Expression Level ◽  
Follicle Cells ◽  
Wool Follicle ◽  
Immunofluorescence Labeling

Abstract To investigate the optimal androgen concentration for culturing Hetian sheep wool follicle and to detect effects of androgen concentration on wool follicle cell proliferation and apoptosis using immunofluorescence labeling and real-time quantitative fluorescence determinations of wool keratin-associated protein gene expression levels. Wool follicles were isolated by microdissection and wool follicles and skin pieces were cultured in various concentrations of dihydrotestosterone (DHT) in culture medium. Next, daily lengthwise growth measurements of wool follicles were obtained using a microscopic micrometer. Cultured Hetian wool follicles were stained using the SACPIC method to reveal wool follicle structure, while sheep skin slices were used to observe cell proliferation by immunostaining and cell apoptosis using the TUNEL method. At the molecular biological level, keratin-associated protein (Kap) gene expression was studied using wool follicles cultured for various numbers of days in vitro. Effects of androgen concentrations on Hetian wool follicle growth and development were experimentally studied. EdU proliferation assays revealed that androgen promoted cell proliferation within wool follicle dermal papillae. TUNEL apoptosis detection demonstrated that androgen treatment could delay cell apoptosis. Quantitative reverse transcription polymerase chain reaction (qPCR) results demonstrated that gene expression level patterns of Hetian mountain sheep super-high sulfur protein. Kap1.1, KIF1.2, Kap2.12 and Kap4.2 gene expression level of the mountainous experimental group was significantly higher than plains Hetian sheep. An androgen concentration of 100 nM can promote the growth of Hetian wool follicle cells in vitro, resulting in overexpression of some genes of the Kap family.

Sign in / Sign up

Export Citation Format

Share Document