Stimulation of embryogenesis in Citrus tissue culture by galactose

1978 ◽  
Vol 65 (5) ◽  
pp. 261-262 ◽  
Author(s):  
J. Kochba ◽  
P. Spiegel-Roy ◽  
S. Saad ◽  
H. Neumann
Keyword(s):  
Tissue Culture ◽  
Citrus Tissue Culture ◽  
Stimulation Of

H+ stimulation of cell-mediated bone resorption in tissue culture

1987 ◽  
Vol 253 (1) ◽  
pp. E90-E98 ◽  
Author(s):  
P. Goldhaber ◽  
L. Rabadjija
Keyword(s):  
Tissue Culture ◽  
Calcium Release ◽  
Bone Destruction ◽  
Calcium Content ◽  
Organic Matrix ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
The Media ◽  
Neonatal Mouse Calvaria ◽  
Stimulation Of

The addition of protons in the form of hydrochloric acid (10.5, 17.2, or 26.6 meq/l resulting in an initial media pH of 7.28, 7.15, and 6.94, respectively) to neonatal mouse calvaria maintained in a chemically defined medium in tissue culture for 1 wk increased calcium release in a dose-response fashion. The same amounts of protons added to the media of devitalized calvaria caused no increase in calcium release into the medium. The net cell-mediated calcium release resulting from the addition of 26.6 meq/l of protons amounted to approximately 50% of the initial calvarial calcium content. Hydroxyproline determinations revealed that active resorption was taking place, wherein both mineral and organic matrix are removed simultaneously. Histological examination of the extensively resorbed calvaria demonstrated the presence of numerous osteoclasts in different stages of bone destruction. The addition of indomethacin (100 ng/ml) strongly inhibited the increase in calcium release by added protons, suggesting that prostaglandin synthesis is involved in the phenomenon. The addition of thyrocalcitonin also inhibited proton-induced calcium release, providing additional evidence that the calcium release from cultures exposed to added protons involved osteoclastic activity.

scholarly journals THE INDUCTION OF MELANIZATION IN GOLDFISH SCALES WITH ACTH, IN VITRO

1963 ◽  
Vol 18 (1) ◽  
pp. 181-194 ◽  
Author(s):  
Alden V. Loud ◽  
Yutaka Mishima
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Silver Nitrate ◽  
Light And Electron Microscopy ◽  
Subcellular Structure ◽  
Acth Stimulation ◽  
Cytoplasmic Bodies ◽  
Silver Nitrate Staining ◽  
Stimulation Of

The induction of melanization in xanthic goldfish scales with ACTH in vitro has been studied by light and electron microscopy utilizing ammoniated silver nitrate staining of premelanin and melanin. The melanized cells (melanophores and melanocytes) and the yellow pigmented cells (lipophores and the newly described lipocytes) were found to possess many similarities at the levels of cellular and subcellular structure. The latter cells contain characteristic cytoplasmic bodies which react positively to the premelanin stain. Changes accompanying ACTH stimulation of goldfish scales in tissue culture suggest that these bodies in the lipocytes and lipophores can become melanized. Electron micrographs illustrate the intermediate staining of newly formed melanin granules in an induced melanocyte and the appearance of a transitional melanolipophore. It is postulated that ACTH can promote the association of the enzyme tyrosinase with the preformed structure of unmelanized granules.

Characterization of insulin glycation in insulin-secreting cells maintained in tissue culture

1997 ◽  
Vol 152 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Y H A Abdel-Wahab ◽  
F P M O'Harte ◽  
C R Barnett ◽  
P R Flatt
Keyword(s):  
Tissue Culture ◽  
Secretory Activity ◽  
Protein Glycation ◽  
Subsequent Exposure ◽  
Insulin Secreting Cells ◽  
Per Se ◽  
Stimulation Of

Abstract Characteristics of cellular insulin glycation were examined in the pancreatic B-cell line, BRIN-BD11. The extent of insulin glycation increased stepwise during 72 h of culture at 5·6–33·3 mmol/l glucose, attaining levels up to 27%. Glycation of insulin at 33·3 mmol/l glucose was rapid, reaching maximal values within 2 h, and not readily reversible during 2 to 24 h of subsequent exposure to 5·6 mmol/l glucose. Glycated insulin was readily secreted by BRIN-BD11 cells upon active stimulation with glucose and other secretagogues. Cellular insulin glycation was decreased by 66–80% by inhibitors of protein glycation, vitamin C, aminoguanidine or acetylsalicylic acid. Modulation of insulin-secretory activity of BRIN-BD11 cells by co-culture at high glucose with diazoxide, l-alanine or glibenclamide indicated that long-term stimulation of secretion was associated with a decrease in the extent of insulin glycation. Glycation of insulin in vitro was substantially less extensive than in BRIN-BD11 cells, although glucose-6-phosphate and glyceraldehyde-3-phosphate were 1·4- to 2·0-fold more reactive than glucose per se. These observations indicate that insulin is readily glycated and secreted from insulin-secreting cells under hyperglycaemic conditions in culture. Journal of Endocrinology (1997) 152, 59–67

Estradiol Stimulation of Glycine Incorporation by Human Endometrium in Tissue Culture

Science ◽  
1961 ◽  
Vol 134 (3494) ◽  
pp. 1986-1987 ◽  
Author(s):  
G. L. Robertson ◽  
D. D. Hagerman ◽  
G. S. Richardson ◽  
C. A. Villee
Keyword(s):  
Tissue Culture ◽  
Human Endometrium ◽  
Estradiol Stimulation ◽  
Stimulation Of

scholarly journals ON THE MECHANISMS OF BONE RESORPTION

1968 ◽  
Vol 39 (3) ◽  
pp. 676-697 ◽  
Author(s):  
Gilbert Vaes
Keyword(s):  
Tissue Culture ◽  
Alkaline Phosphatase ◽  
Protein Synthesis ◽  
Bone Resorption ◽  
Bone Mineral ◽  
Lysosomal Enzymes ◽  
Organic Matrix ◽  
Acid Hydrolases ◽  
New Synthesis ◽  
Stimulation Of

Bone resorption, characterized by the solubilization of both the mineral and the organic components of the osseous matrix, was obtained in tissue culture under the action of parathyroid hormone (PTH). It was accompanied by the excretion of six lysosomal acid hydrolases, which was in good correlation with the progress of the resorption evaluated by the release of phosphate, calcium 45 or hydroxyproline from the explants; there was no increased excretion of two nonlysosomal enzymes, alkaline phosphatase, and catalase. Balance studies and experiments with inhibitors of protein synthesis indicated that the intracellular stores of the acid hydrolases excreted were maintained by new synthesis. The release was not due to a direct disruption of the lysosomal membrane by PTH; it is presumed to result from an exocytosis of the whole lysosomal content and to involve mechanisms similar to those controlling the secretion of this content into digestive vacuoles. The resorbing explants acidified their culture fluids at a faster rate and released more lactate and citrate than the controls; this release was in good correlation, in the PTH-treated cultures, with the resorption of the bone mineral, but the amount of citrate released was considerably smaller than that of lactate. The acid released could account for the resorption of the mineral. It is proposed, as a working hypothesis, that the acid hydrolases of the lysosomes are active in the resorption of the organic matrix of bone and that acid, originating possibly from the stimulation of glycolysis, cares for the concomitant solubilization of bone mineral while also favoring the hydrolytic action of the lysosomal enzymes.

OESTRADIOL STIMULATION OF PROLACTING RELEASE FROM CANINE PITUITARY IN CULTURE

1976 ◽  
Vol 82 (3) ◽  
pp. 706-709 ◽  
Author(s):  
Gwyneth E. Jones ◽  
A. R. Boyns
Keyword(s):  
Tissue Culture ◽  
Luteinizing Hormone ◽  
Prolactin Release ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Thyrotrophic Hormone ◽  
Lh Rh ◽  
Stimulation Of

ABSTRACT Anterior canine pituitaries were maintained in tissue culture for 8 days, and the immunoreactive prolactin released, was measured by a heterologous radioimmunoassay for canine prolactin. Luteinizing hormone-releasing hormone (LH-RH) and thyrotrophic hormone-releasing hormone (TRH) did not affect prolactin release, while theophylline and oestradiol-17β stimulated the release of canine prolactin.

Citrus tissue culture: regulation of stylar abscission in excised pistils

1980 ◽  
Vol 58 (11) ◽  
pp. 1257-1261 ◽  
Author(s):  
John W. Einset ◽  
Anne Cheng ◽  
Hamid Elhag
Keyword(s):  
Tissue Culture ◽  
Cell Division ◽  
Dichlorophenoxyacetic Acid ◽  
Navel Orange ◽  
Test Medium ◽  
Fresh Weight ◽  
Valencia Orange ◽  
Washington Navel ◽  
Citrus Tissue Culture ◽  
2,4 Dichlorophenoxyacetic Acid

Lemon pistil explants were obtained by cutting just above the region of the hypogynous disc (A type explant) or at the base of the pistil (B type explant) and cultured on test medium containing Murashige and Skoog salts, 50 g sucrose/L, 100 mg myo-inositol/L, 5 mg thiamine–HCl/L, and 0.5 mg kinetin/L, plus or minus supplements. Under appropriate conditions an abscission zone formed and styles abscised after 6–8 days of culture; in the field stylar abscission occurred 12–15 days postanthesis. Abscission in A type explants was markedly inhibited by 9 μM 2,4-dichlorophenoxyacetic acid but was unaffected by indole-3-acetic, 1-naphthaleneacetic, gibberellic, abscisic, caffeic, or p-coumaric acids. The response to 2,4-dichlorophenoxyacetic acid was reduced in B type explants. In an atmosphere containing 35–200 ppm ethylene, cell division occurred in the zone of stylar abscission producing a proliferating callus, and the content of cellulase increased from 0.6 to 53.7 enzyme units/g fresh weight compared with fresh explants. Stylar abscission was inhibited by 2,4-dichlorophenoxyacetic acid in A type explants of Washington navel orange, Valencia orange, and mandarin pistils, but not of grapefruit pistils. B type explants of Washington navel orange and mandarin pistils were less responsive to 2,4-dichlorophenoxyacetic acid.

scholarly journals Citrus Tissue Culture

1978 ◽  
Vol 62 (6) ◽  
pp. 885-888 ◽  
Author(s):  
John W. Einset
Keyword(s):  
Tissue Culture ◽  
Citrus Tissue Culture
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