16 Glucose-6-Phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase Activities in Coelenterates

1971 ◽  
pp. 169-176
Author(s):  
Dennis A. Powers
Keyword(s):  
Phosphogluconate Dehydrogenase ◽  
Glucose 6 Phosphate Dehydrogenase

CHANGES IN ENZYMES OF CARBOHYDRATE METABOLISM IN RAT UTERUS DURING EARLY PREGNANCY

1971 ◽  
Vol 68 (4) ◽  
pp. 805-816 ◽  
Author(s):  
M. A. H. Surani ◽  
P. J. Heald
Keyword(s):  
Energy Requirement ◽  
Lipid Synthesis ◽  
Dry Weight ◽  
Glycolytic Enzymes ◽  
Rat Uterus ◽  
Malic Dehydrogenase ◽  
Phosphogluconate Dehydrogenase ◽  
Tissue Changes ◽  
Implantation Sites ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT The enzymes phosphofructokinase (PFK), pyruvate kinase (PK), isocitric dehydrogenase (ICDH), malic dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G-6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) have been measured in rat uterus during the first 9 days of pregnancy. It was found that after implantation on day 6, the activities of PFK and PK (the key glycolytic enzymes) increased in terms of dry weight — and in terms of protein in the implantation sites, but decreased in non-implanted tissue. The pentose shunt enzymes changed similarly to those of the glycolytic enzymes. ICDH activity increased in the non-implanted tissue and decreased in the implanted tissue. Changes in malic dehydrogenase were extremely variable and did not show a consistent pattern. Administration of Actinomycin D on day 6 of pregnancy abolished the increase in PK and PFK in the implantation sites and indeed led to a major decrease in activity. This implies that the increased PK and PFK in the implantation sites, arise from a DNA dependent RNA directed synthesis of new enzyme protein. The results are discussed in relation to the energy requirement of the decidualising tissue and the need for increased pentose for RNA synthesis. It is suggested that the extra NADPH resulting from the pentose shunt is involved in increased lipid synthesis.

EINFLUSS VON CYCLUS UND EXOGENER HORMONZUFUHR AUF STOFFWECHSELVORGÄNGE DES RATTENUTERUS

1967 ◽  
Vol 56 (2) ◽  
pp. 231-243 ◽  
Author(s):  
H. Schmidt ◽  
I. Noack ◽  
H. Walther ◽  
K. D. Voigt
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Leucine Aminopeptidase ◽  
Intraperitoneal Administration ◽  
Exogenous Hormone ◽  
Rat Uterus ◽  
Normal Cycle ◽  
Phosphogluconate Dehydrogenase ◽  
Dna And Rna ◽  
Hormone Administration ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT The first significant increase of weight, RNA and protein was observed in the uterus of spayed rats twelve hours after the intraperitoneal administration of a single dose of 1 μg oestradiol. There was no significant increase of DNA. At the same time the activities of glucose-6-phosphate dehydrogenase, fructose-1,6-diphosphate aldolase, isocitrate dehydrogenase and leucine aminopeptidase had increased significantly. Twentyfour hours after the injection the augmented values began to decline. Three injections of 1 μg oestradiol, given at 24 hour intervals obtained similar changes, the only difference being that these changes were more marked and that a DNA increase was also observed. The augmentation of protein, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and fructose-1,6-diphosphate aldolase content of cells induced by repeated oestradiol injections was inhibited partly by 1 mg progesterone when administered together with the last dose of oestradiol. During the normal oestrus cycle of the rat uterus an increase of uterine weight, DNA and RNA content and also of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and 1,6-diphosphate aldolase activities was observed, whereas isocitrate dehydrogenase, malate dehydrogenase and leucine aminopeptidase did not change significantly. It would appear that the changes after exogenous hormone administration reflect those of the normal cycle as regards both their extent and timing. The importance of these findings in connection with hormone-induced pathways of uterine metabolism is discussed.

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