Environmental influences on the metabolism and composition of cultured cells

Paul, John

doi:10.1002/jez.1401420122

Cited by 51 publications

(13 citation statements)

References 33 publications

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“…of the cells show pinocytosis in vivo, but the number can be increased in vitro by growing the cells flattened out as monolayers on glass, implying that in this case pinocytosis occurs more readily in flattened than in spherical cells. The lack of uptake of fluorescent-labelled insulin by hamster kidney normal and tumour cells and mouse ascites tumour cells is interesting, in view of the claims that this hormone promotes pinocytosis (Paul, 1959) and stimulates metabolism and growth of cells in tissue culture. There are three possible explanations which might be considered.…”

Section: Discussionmentioning

confidence: 99%

“…There are three possible explanations which might be considered. In the first place, the cell types chosen, unlike the HeLa cells used by Paul (1959), might be refractory to insulin. Alternatively, insulin may exert its effect in the cell types we have studied by a localized action at the cell surface, without actually entering the cytoplasm.…”

Section: Discussionmentioning

confidence: 99%

“…Insulin (Boots) was also chosen because, although much work has been done on the effects of this hormone on cells in vitro and in vivo, the actual site of action of insulin remains obscure. We also wished to check on the claims that insulin promotes pinocytosis (Paul, 1959).…”

Section: Choice Of Proteinmentioning

confidence: 99%

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The Cellular Uptake of Proteins Labelled With Fluorescent Dyes

Cormack

Ambrose

1962

Journal of the Royal Microscopical Society

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SYNOPSIS The use of the direct fluorescent‐labelling technique as a method for demonstrating the uptake of proteins by living cells is evaluated. This technique has been applied to the uptake of wheat‐germ “lipase” and insulin by a selection of normal and malignant cell types. Some enzymatic activity of the “lipase”, which shows aliesterase activity, has been shown to remain after the labelling procedure. It was taken up in relatively large amounts by pinocytosis, and accumulated on the cell membrane of normal cells. Insulin did not appear to be taken up by pinocytosis.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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The Cellular Uptake of Proteins Labelled With Fluorescent Dyes

Cormack

Ambrose

1962

Journal of the Royal Microscopical Society

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“…The metabolic effects of insulin have been studied, using fresh chick embryo and L cells (188). Carbohydrate metabolism was stimulated, with a rise in glucose utilization and lactate production, while pyruvate levels in the medium fell, Stimulation of synthetic processes was found to be erratic, especially with fresh explants.…”

Section: Methods Used I N Assessing the Beneficial A N D Adverse Effementioning

confidence: 98%

“…Failure was attributed to differing sensitivities of cell types (those used here being hamster kidney, both normal and tumor and Landschiitz ascites cells) since Paul (188) had noted a greatly increased rate of pinocytosis (k., uptake) in HeLa cells. This he conjectured to be due to either more energy made available to the cell by insulin for this kind of activity or a direct action of insulin on the cell membrane.…”

Section: Methods Used I N Assessing the Beneficial A N D Adverse Effementioning

confidence: 98%

Tissue Culture in the Study of the Effects of Drugs

Dawson

Dryden

1967

Journal of Pharmaceutical Sciences

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Glucose and lactic acid trends in suspension cultures of two established mammalian cell strains in chemically defined media

Bryant

1970

Biotech & Bioengineering

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SummaryIn replicated 30 to a m 1 suspension cultures of rapidly proliferating monkey kidney cells of a comparatively fragile strain, the rates of glucose utilization and lactic acid accumulation averaged about -100 micrograms and 110 micrograms per 106 cells per day respectively, with average molar La/G1 ratios of 0.48. These two rates of glucose utilization and lactic acid accumulation were about 4 x and 1Ox as high as the corresponding rates in comparable cultures of the hardier strain 2071-L mouse fibroblasts under the same conditions, with average molar La/G1 ratios of 0.16. In comparable but nonproliferating suspension cultures of the same strain of monkey kidney cells, during about 3 weeks the rates were extremely high, with about 710 micrograms glucose utilized and 445 micrograms lactic acid accumulated per 106 cells per day, with average molar La/G1 ratios of 1.37. The rates of glucose uptake and lactic acid accumulation were higher in the nonproliferating cultures aerated with 570 CO, in air than in those aerated with 10% CO, in air. This difference was aasociated with pH, which was higher in the former group.It was concluded that with this fragile strain of monkey kidney cells ( 1 ) in nonproliferating cultures the cells were metabolizing actively but with a marked tendency to higher La/Gl ratios, ( 2 ) in the proliferating cultures the high rates of glucose utilization and lactic acid accumulation were definitely not directly correlated with the rate of growth, and (3) in none of the cultures was the amount of glucose remaining in the fluid at fluid changes so low as to have been a limiting factor.Information in the literature concerning glucose utilization and lactic acid production by cells in vitro is voluminous and in some respects contradictory. 430 JAY C. BRYANTIn the present study the rates were unexpectedly high for the monkey kidney cells, particularly those in the otherwise apparently inactive nonproliferating cultures. The data seem to be unique, in that an established strain of cells in chemically defined medium in suspension cultures has been characterized for these metabolic parameters in both proliferating cultures and in equivalent nonproliferating cultures under directly comparable conditions. The concept waa developed that since these monkey kidney cells are obviously more fragile than the other cells examined, the complex physical stresses imposed upon these cells in agitated cultures can be modified and lessened in order to permit growth. Lessening of such mechanical stress waa brought about in several ways, of which only the smaller flask size seemed to be a t least partly effective. Increasing eit,her the concentration or the viscosity type of Methocel waa not effective.

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Environmental influences on the metabolism and composition of cultured cells

Cited by 51 publications

References 33 publications

The Cellular Uptake of Proteins Labelled With Fluorescent Dyes

The Cellular Uptake of Proteins Labelled With Fluorescent Dyes

Tissue Culture in the Study of the Effects of Drugs

Glucose and lactic acid trends in suspension cultures of two established mammalian cell strains in chemically defined media

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