Glucose-6-Phosphate Dehydrogenase from Lactating Rat Mammary Gland and R3230AC Adenocarcinoma

Enzyme ◽  
1979 ◽  
Vol 24 (1) ◽  
pp. 48-53 ◽  
Author(s):  
David S. Shreve ◽  
H. Richard Levy
Keyword(s):  
Mammary Gland ◽  
Rat Mammary Gland ◽  
Glucose 6 Phosphate Dehydrogenase

scholarly journals Effect of thyroidectomy on pathways of glucose metabolism in lactating rat mammary gland

1967 ◽  
Vol 105 (2) ◽  
pp. 615-623 ◽  
Author(s):  
Eileen Walters ◽  
Patricia McLean
Keyword(s):  
Mammary Gland ◽  
Glucose Oxidation ◽  
Mammary Tissue ◽  
Control Group ◽  
Phosphogluconate Dehydrogenase ◽  
Lactating Mammary Gland ◽  
Cleavage Enzyme ◽  
Rat Mammary Gland ◽  
Group 3 ◽  
Glucose 6 Phosphate Dehydrogenase

1. Assessment of the overall metabolic changes in lactating mammary gland after thyroidectomy has been made by measurement of the incorporation of 14C from specifically labelled glucose, pyruvate and acetate into 14CO2 and 14C-labelled lipid in the experimental rats and in sham-operated control animals. 2. Thyroidectomy depressed the oxidation of 14C-labelled substrates, an effect still apparent when the control rats were pair-fed with thyroidectomized rats; however, the ratio of oxidation of [1−14C]glucose/oxidation of [6−14C]glucose was unaltered. In parallel with these studies it was revealed that the activities of hexokinase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and NADP-linked isocitrate dehydrogenase were all lower in the thyroidectomized group than in the pair-fed control group. 3. Thyroidectomy also lowered the incorporation of 14C-labelled substrates into 14C-labelled lipid, an effect further studied by measurement of the activities of citrate-cleavage enzyme and acetate thiokinase. Restricting the food intake of the control rats to that of the thyroidectomized group lowered the activity of citrate-cleavage enzyme, but no further depression was observed on thyroidectomy. The oxidized and reduced nicotinamide nucleotide content of mammary tissue was shown to be decreased in the thyroidectomized rats compared with the control rats.

scholarly journals Lactogenesis in the rat. Metabolism of uridine diphosphate galactose by mammary gland

1968 ◽  
Vol 106 (3) ◽  
pp. 743-748 ◽  
Author(s):  
N. J. Kuhn
Keyword(s):  
Mammary Gland ◽  
Synthetase Activity ◽  
Uridine Diphosphate ◽  
Parallel Increase ◽  
Hydrolytic Activities ◽  
Before And After ◽  
Rat Mammary Gland ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Rate Limiting

1. Lactose synthetase activity in the rat mammary gland increases during the last day of pregnancy from an essentially zero value. There is a parallel increase of tissue lactose and of glucose 6-phosphate dehydrogenase activity. 2. Mammary-gland homogenates prepared both before and after parturition hydrolyse the lactose precursors glucose 6-phosphate, glucose 1-phosphate, UDP-glucose, UDP-galactose and also maltose, but not lactose. 3. A role of lactose synthetase as the rate-limiting enzyme for lactose biosynthesis and the possible significance of the hydrolytic activities are discussed with respect to lactogenesis.

Rat mammary gland metabolism relative to epithelial and connective tissue content

1964 ◽  
Vol 207 (3) ◽  
pp. 595-600 ◽  
Author(s):  
E. Douglas Rees ◽  
Amy Eversole
Keyword(s):  
Mammary Gland ◽  
Aerobic Glycolysis ◽  
Mammary Epithelium ◽  
Total Activity ◽  
Mammary Glands ◽  
Epithelial Cell Proliferation ◽  
Epithelial Proliferation ◽  
Pregnancy And Lactation ◽  
Rat Mammary Gland ◽  
Glucose 6 Phosphate Dehydrogenase

The respiration rate of rat mammary gland slices increased directly with the epithelial proliferation induced by pregnancy and lactation. In the absence of glucose the respiration was depressed, particularly in slices with the largest epithelial content. Dinitrophenol (5 x 10–5 m) provided a metabolic distinction between the epithelium of pregnant and lactating mammary glands; it stimulated the respiration of the former and depressed the respiration of the latter. The rate of anaerobic glycolysis (q1acN2) for mammary epithelium was adduced to be 4–5 µl/hr mg dry nonfat tissue and the rate remained in that range during lactation and pregnancy; the rate of aerobic glycolysis increased during pregnancy and decreased during lactation. Alkaline phosphatase activity did not vary directly with the mammary epithelium content and it was suggested that the rate of epithelial cell proliferation (mitoses) and hormonal factors might also be of importance in determining the total activity observed. The increase in glucose 6-phosphate dehydrogenase and 6-phosphogluconic acid dehydrogenase activity during pregnancy and at the onset of lactation was not directly related to the increase in mammary epithelium.

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