scholarly journals Quantitative studies of pinocytosis. I. Kinetics of uptake of (125I)polyvinylpyrrolidone by rat yolk sac cultured in vitro.

1975 ◽  
Vol 64 (1) ◽  
pp. 113-122 ◽  
Author(s):  
K E Williams ◽  
E M Kidston ◽  
F Beck ◽  
J B Lloyd
Keyword(s):  
Electron Microscopy ◽  
In Vitro Culture ◽  
Quantitative Study ◽  
Light And Electron Microscopy ◽  
Yolk Sac ◽  
Quantitative Studies ◽  
Visceral Yolk Sac ◽  
Kinetics Of Uptake ◽  
Kinetics Of

A method is described for the in vitro culture of 17.5-day rat visceral yolk sac. Tissue survival was good as judged by light and electron microscopy. The rate of pinocytic uptake of 125I-labeled polyvinylpyrrolidone by the tissue was constant both within and between experiments. Within the concentration range 0.15-24 mug/ml, the 125I-labeled polyvinylpyrrolidone neither stimulated nor inhibited pinocytosis. The system offers many advantages in the quantitative study of the physical basis of pinocytosis.

scholarly journals Quantitative studies of pinocytosis. II. Kinetics of protein uptake and digestion by rat yolk sac cultured in vitro.

1975 ◽  
Vol 64 (1) ◽  
pp. 123-134 ◽  
Author(s):  
K E Williams ◽  
E M Kidston ◽  
F Beck ◽  
J B Lloyd
Keyword(s):  
Plasma Membrane ◽  
Initial Period ◽  
Yolk Sac ◽  
Membrane Receptors ◽  
Protein Uptake ◽  
Quantitative Studies ◽  
Intracellular Digestion ◽  
Visceral Yolk Sac ◽  
Plasma Membrane Receptors

Pinocytic uptake of 125I-labeled bovine serum albumin by 17.5-day rat visceral yolk sac cultured in vitro has been examined. Uptake was followed by intracellular digestion and, after an initial period, the content of radioactivity in the tissue itself remained constant during the incubation. Radiolabel was returned to the culture medium predominantly as (125I)iodotyrosine; exocytosis of undigested protein did not occur. The rate of uptake of labeled protein, which was constant within an experiment and reproducible between experiments, was much higher than that of a nondigestible macromolecule, 125I-labeled polyvinylpyrrolidone. The higher rate of uptake was a consequence of the protein entering the cells chiefly by adsorption to the plasma membrane being internalized; 125I-labeled albumin did not stimualte, nor did 125I-labeled polyvinylpyrrolidone inhibit pinocytosis. Different preparations of 125I-labeled albumin had characteristically different rates of uptake, probably reflecting differences in affinity for plasma membrane receptors. The physiological significance of the findings is discussed.

Differentiation potentiality of rat visceral yolk sac in organ culture

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 127-136
Author(s):  
Y. L. Lu ◽  
H. Sobis ◽  
L. Van Hove ◽  
M. Vandeputte
Keyword(s):  
Organ Culture ◽  
In Vitro Culture ◽  
Yolk Sac ◽  
Trophoblast Cells ◽  
Differentiated Cells ◽  
Visceral Yolk Sac ◽  
Poorly Differentiated

Visceral yolk sacs removed at day 12 of pregnancy in the rat were kept in organ culture for as long as 28 days. During this in vitro culture, proliferation of the endoderm and the mesoderm as well as of poorly differentiated cells was observed. The latter displayed neither the characteristics of endodermal nor mesodermal cells and their presence was frequently associated with the development of giant trophoblast cells. The hypothesis is proposed that these trophoblast cells originate from these poorly differentiated cells that acquire in vivo and in vitro the potentiality to differentiate.

Development of an in vitro Model for the Study of the Response of Equine Tendon Fibroblasts to Injury and Medication

1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren
Keyword(s):  
Electron Microscopy ◽  
Extracellular Matrix ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Tendon Healing ◽  
Matrix Proteins ◽  
Isolated Cells ◽  
Superficial Digital Flexor Tendon ◽  
Vitro Model

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.

A Method of Maintaining Parenchymal Cells from Adult Rat Liver In Vitro

1972 ◽  
Vol 11 (1) ◽  
pp. 249-260
Author(s):  
J. ALWEN ◽  
JENNIFER J. GALLHAI-ATCHARD
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Protein Synthesis ◽  
Light And Electron Microscopy ◽  
Rat Hepatocytes ◽  
Adult Rat ◽  
Adult Rat Hepatocytes ◽  
Rna And Protein Synthesis ◽  
Parenchymal Cells

A method for preparing suspensions of adult rat hepatocytes suitable for maintenance in vitro is described. Cultures were established from the cell suspensions by the squash technique. Cells were examined by light and electron microscopy; histochemically for glycogen, bile, lipid and glucose-6-phosphatase; and by autoradiography for DNA, RNA and protein synthesis. Hepatocytes could be maintained in vitro for at least 3 days and began to aggregate after 1 day. Uridine and leucine were incorporated, but not thymidine. Cultures consisted mainly of hepatocytes, though reticulo-endothelial cells were sometimes present.

Cytasters induced within unfertilized sea-urchin eggs

1983 ◽  
Vol 61 (1) ◽  
pp. 175-189
Author(s):  
R. Kuriyama ◽  
G.G. Borisy
Keyword(s):  
Electron Microscopy ◽  
Sea Urchin ◽  
Sea Water ◽  
Light And Electron Microscopy ◽  
Sea Urchin Eggs ◽  
Microtubule Organizing Centres ◽  
Treatment Step

Conditions that induce the formation of asters in unfertilized sea-urchin eggs have been investigated. Monasters were formed by treatment of eggs with acidic or basic sea-water, or procaine- or thymol-containing sea-water. A second treatment step, incubation with D2O-containing, ethanol-containing or hypertonic sea-water induced multiple cytasters. The number and size of cytasters varied according to the concentration of agents and duration of the first and second treatments, and also upon the species of eggs and the season in which the eggs were obtained. Generally, a longer second treatment or a higher concentration of the second medium resulted in a higher number of cytasters per egg. Asters were isolated and then examined by light and electron microscopy. Isolated monasters apparently lacked centrioles, whereas cytasters obtained from eggs undergoing the two-step treatment contained one or more centrioles. Up to eight centrioles were seen in a single aster; the centrioles appeared to have been produced during the second incubation. Centrospheres prepared from isolated asters retained the capacity to nucleate the formation of microtubules in vitro as assayed by light and electron microscopy. Many microtubules radiated from the centre of isolated asters, whether they contained centrioles or not. This observation is consistent with many other reports that microtubule-organizing centres need not contain centrioles.

Effect of yolk-sac antibody on rat embryos grown in culture

Development ◽  
1972 ◽  
Vol 27 (3) ◽  
pp. 543-553
Author(s):  
D. A. T. New ◽  
R. L. Brent
Keyword(s):  
Direct Contact ◽  
Culture Medium ◽  
Gamma Globulin ◽  
Yolk Sac ◽  
Amniotic Cavity ◽  
Pregnant Rats ◽  
Rat Embryos ◽  
Visceral Yolk Sac ◽  
Primary Action

Rat embryos, explanted with their embryonic membranes during the early stages of organogenesis ( days gestation), were grown in culture in roller tubes. Yolk-sac antibody (sheep anti rat yolk-sac gamma globulin), known to be teratogenic when injected into pregnant rats, was added to the culture medium. At concentrations of 0·1 mg/ml or more the antibody caused gross retardation of growth and differentiation. Injection of antibody into the amniotic cavity so that it had direct contact with the embryo, or between the amnion and yolk sac so that it was in contact with the mesodermal surface of the yolk sac, had little or no effect on development of the embryo or its membranes. These in vitro experiments indicate that yolk-sac antibody has an effect on development independent of any immunological reaction of the mother, and the primary action is probably on the visceral yolk-sac endoderm.

scholarly journals Kinetics of BoHV-1 Dissemination in an in Vitro Culture of Bovine Upper Respiratory Tract Mucosa Explants

ILAR Journal ◽  
2012 ◽  
Vol 53 (1) ◽  
pp. E43-E54 ◽  
Author(s):  
L. Steukers ◽  
A. P. Vandekerckhove ◽  
W. Van den Broeck ◽  
S. Glorieux ◽  
H. J. Nauwynck
Keyword(s):  
Respiratory Tract ◽  
In Vitro Culture ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Kinetics Of
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