Autoradiographic study of cell renewal in fundic mucosa of fasting dogs

Willems, Glenda; Vansteenkiste, Y.; Verbeustel, Suzanne

doi:10.1159/000143671

Cited by 27 publications

(12 citation statements)

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“…In the same experiments, we observed a definite labelling of chief cells after one 3H-thymidine pulse, and afterwards, evidence of division in these cells. The fact that R ubin et al [60] were unable to distinguish intermediate forms between immature progenitor cells and chief cells and that other authors had described the ability of chief cells to synthetize DNA [27,29,50,65] further supports the hypothesis that in adult animals, chief cells have an autonomous turnover which is independent of that occurring in the middle part of the gland. The other two epithelial cell types probably originate from mother cells situated in the latter area.…”

Section: Origin Of the Mucosal Cellsmentioning

confidence: 85%

“…In slowly-proliferating tissues as in the fundus of fasting dogs [65], the second wave of labelled mitosis is considerably delayed and might not be observed within the 24 h following injection of 3H-thymidine. If Tc cannot be measured directly on the latter curve, it is theoretically possible to calculate its value, knowing the length of the S-phase (Ts) and the LI.…”

Section: Cell Cycle Timementioning

confidence: 97%

“…For similar reasons, the basal segment of the glands, including differentiated chief and parietal cells must be eliminated from the total count. We proposed to delineate the area of maximal proliferation in normal fundic glands by taking as a fixed reference point the limit between mucous neck and foveolar cells [65]. After PAS reaction, the former can be easily distinguished from the latter by the pink foamy appearance of their intra cellular mucus [60,61], especially in man and dog [22].…”

Section: Kinetic Parametersmentioning

confidence: 99%

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Cell Renewal in the Gastric Mucosa

Willems¹

1972

Digestion

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The mechanisms controlling cell division in the stomach are still unknown. Among the procedures available for determining kinetic parameters in the mucosa, autoradiographic methods with ³H-thymidine are the most widely used. As yet, they have allowed observation of two basic control factors in the gastric mucosa: A tissue specific inhibitory substance of mitotic activity called ‘gastric chalone’ and a stimulating hormone released after food ingestion, which is most probably gastrin. Other possible factors are now to be further investigated.

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Section: Origin Of the Mucosal Cellsmentioning

confidence: 85%

Section: Cell Cycle Timementioning

confidence: 97%

Section: Kinetic Parametersmentioning

confidence: 99%

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Cell Renewal in the Gastric Mucosa

Willems¹

1972

Digestion

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“…It has been demonstrated that fasting de creases the mitotic rate in the gastric mucosa [11,36], indicating a lower cell proliferation in the tissue. In the present investigation, when the rate of cell proliferation in the gas tric mucosa was assessed by measuring the activity of thymidine kinase and DNA poly merase in the tissue, marked diminutions in the activity of both enzymes were observed after 1-4 days of starvation ( fig.…”

Section: Discussionmentioning

confidence: 99%

“…However, since the observa tion was made after administration of a large dose of tryptophan, the physiological significance of dietary tryptophan in main taining the structural and functional proper ties of the stomach could not be evaluated with confidence. Recently, we have ob served that whereas fasting by itself lowers the activity of a number of intestinal diges tive enzymes, refeeding of a complete but not tryptophan-free diet reverses the situa tion [17], Fasting by itself lowers gastric mucosal cell proliferation as evidenced by the de creased mitotic rate and 3H-thymidine up take [11,36]. However, the biochemical changes associated with these have not been studied in detail.…”

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confidence: 99%

Effects of Fasting and Subsequent Feeding of a Complete or Tryptophan-Free Diet on the Activity of DNA-Synthesizing Enzymes and Protein Synthesis in Gastric Mucosa of Rats

Nandi Majumdar

1982

Ann Nutr Metab

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Effects of fasting for 1–4 days and subsequent feeding of 4-day fasted rats with a complete or tryptophan-free liquid diet (40 kcal/day) for 1–4 days on the activity of thymidine kinase and DNA polymerase and protein synthesis were investigated in gastric mucosa. Rats maintained on ad libitum chow pellets served as control. Starvation for 1–4 days diminished gastric mucosal thymidine kinase and DNA polymerase activities, which attained their respective lowest levels of 53 and 65% of the fed control (chow-fed) after 2 days. Refeeding the complete diet for 1 day increased thymidine kinase activity to 87% of the fed control; it increased slightly thereafter. The tryptophan-free diet was ineffective in stimulating gastric mucosal thymidine kinase for up to 3 days, but after 4 days on the diet the enzyme activity was increased to 78% of the fed control level. On the other hand, DNA polymerase activity began to increase after 1 day on the tryptophan-free diet and reached the fed control level after 4 days. The complete diet caused an initial reduction (for up to 2 days) in DNA polymerase activity, but after 3 days it rose to the level of the fed control. The ability of gastric mucosal polyribosomes to synthesize endogenous mRNA-directed protein in a cell-free system was decreased by 44 % after 4 days of fasting. Whereas refeeding of the complete diet for 4 days enhanced protein synthesis to 75 % of the fed control level, the tryptophan-free diet was found to be ineffective. The protein to polyphenylalanine ratio, which represents a ratio of poly-somes to monosomes, was also decreased by 42% after 4 days of fasting, but could be returned to the fed control level by the complete diet and not by the tryptophan-free diet. It is concluded that the presence of tryptophan in the dietary mixture is important for initiation of cellular proliferative activity and for resumption of protein synthesis in the gastric mucosa of fasted rats.

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Glycoprotein synthesis in the mucous cells of the vascularly perfused rat stomach. II. Differentiating mucous cells

et al. 1979

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Labeled leucine, serine, galactose, glucosamine and sulphate were administered to rat stomachs in a perfusion system. Sections of the gastric fundus were studied by light microscopic autoradiography. Five categories of mucous cells were distinguished and their glycoprotein synthetic activity was measured in autoradiographs by counting silver grains over each category. During their differentiation, while migrating from the isthmus of the fundic glands to the free luminal surface, the surface mucous cells (SMC) showed an increase in incorporation of all precursors used. Differences between the incorporation patterns of the various precursors, in cells of different ages, suggest that structural development runs ahead of functional activity, and that the latter continues up to the very moment the cell is shed from the surface. Sulphate was incorporated at a considerably lower rate by the SMC of the free surface than by the foveolar SMC, in which by cytochemical staining strongly acidic glycoproteins were shown. Since the mucous neck cells incorporated all precursors at a low rate, these cells apparently do not play an important role in gastric mucus synthesis. They did not incorporate sulphate, which is consistent with histochemical observations.

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Autoradiographic study of cell renewal in fundic mucosa of fasting dogs

Cited by 27 publications

References 1 publication

Cell Renewal in the Gastric Mucosa

Cell Renewal in the Gastric Mucosa

Effects of Fasting and Subsequent Feeding of a Complete or Tryptophan-Free Diet on the Activity of DNA-Synthesizing Enzymes and Protein Synthesis in Gastric Mucosa of Rats

Glycoprotein synthesis in the mucous cells of the vascularly perfused rat stomach. II. Differentiating mucous cells

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