“A Microsomal Malic Dehydrogenase”

Nature ◽  
1960 ◽  
Vol 185 (4713) ◽  
pp. 582-582
Keyword(s):  
1956 ◽  
Vol 187 (3) ◽  
pp. 427-431 ◽  
Author(s):  
Joseph J. Vitale ◽  
Oscar M. Jankelson ◽  
Patricia Connors ◽  
D. Mark Hegsted ◽  
Norman Zamcheck

Effect of histamine on the activity of succinic oxidase and malic dehydrogenase was studied in guinea pig and human gastric mucosa. Human tissue was obtained through the surgical services of the Boston City Hospital. Control value for the succinic oxidase system of the proximal half of the guinea pig stomach was approximately 480 ( Qo2 (N) (µl O2/mg nitrogen/hr.)). After histamine, this value rose to 550 in 30 minutes with a simultaneous rise in titratable acidity of the stomach contents. Animals fasted for 72 hours had a Qo2 (N) of approximately 500 and after histamine a Qo2 (N) of 700 was observed. Spectrophotometric analysis of succinic dehydrogenase and cytochrome oxidase activities, two of the major components of the succinic oxidase system, revealed that both components are increased following histamine administration. Malic dehydrogenase, however, was not affected by histamine treatment. Succinic dehydrogenase was demonstrated by histochemical localization and was concentrated below the superficial mucous layer where parietal cells were abundant. Succinic oxidase activity of human gastric mucosa was demonstrable only in those specimens containing abundant parietal cells. This study confirms the view that HCl production by parietal cells is associated with aerobic metabolism and is perhaps under enzymatic control. The study suggests that the succinic oxidase system may be involved in the production or secretion of HCl.


1996 ◽  
Vol 82 (1) ◽  
pp. 92-94 ◽  
Author(s):  
C. Cutillas ◽  
P. Arias ◽  
M. Spakulova

1971 ◽  
Vol 68 (4) ◽  
pp. 805-816 ◽  
Author(s):  
M. A. H. Surani ◽  
P. J. Heald

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.


Author(s):  
YASSER HUSSEIN EISSA MOHAMMED ◽  
DEEPIKA HS ◽  
FARES HEZAM AL-OSTOOT ◽  
ZABIULLA ◽  
ANILAKUMAR ◽  
...  

Objective: The objective of the study was to in vitro evaluate of hypolipidemic effect of extracts of medicinal Dracaena cinnabari Balf. f. resin. Methods: About 800 g of dry powder of the resin of dracaena cinnabar was taken in a Soxhlet apparatus and subjected for sequential extraction of solvents from non-polar to polar end (hexane, benzene, diethyl ether, dichloromethane, chloroform, ethyl acetate, acetone, ethanol, methanol, and water); the extract samples were kept at 4°C for further assays. All the extracts were subjected to glucose uptake assay. Results: The ethanol extract showed significant (p<0.05) hypolipidemic effect by decreasing the activity of enzyme such as significant reduction in the pancreatic lipase enzyme, malic dehydrogenase enzyme, and glucose-6-phosphate dehydrogenase enzyme with IC50~13, ~13, and ~14, respectively. This results were similar to the standard drug atorvastatin with IC50~12, ~16, and ~17, respectively. Ethanol extract exhibited significant atherogenic index and percentage protection against hyperlipidemia. The potential biological activity of ethanol extract may be attributed to the highest polarity which needs further investigation.


1961 ◽  
Vol 47 (2) ◽  
pp. 279 ◽  
Author(s):  
Harry D. Baernstein

1978 ◽  
Vol 68 (1) ◽  
pp. 85-97 ◽  
Author(s):  
S. J. Miles

AbstractThe genotypes of chromosomally-identified individuals from natural populations of the known species of the group of Anopheles gambiae Giles were scored for the enzyme protein structural loci coding for adenylate kinase (Adk), α-naphthyl acetate esterase (Est-1, Est-2, Est-3), glutamic-oxaloacetic transaminase (Got), α-glycerophosphate dehydrogenase (αGpd), hexokinase (Hk), isocitric dehydrogenase (Idh), lactic dehydrogenase (Ldh), ‘leucine’ aminopeptidase (Lap-2), malic enzyme (Me), octanol dehydrogenase (Odh), phosphoglucomutase (Pgm-1, Pgm-2), 6-phosphogluconic dehydrogenase (6-Pgd), phosphohexose isomerase (Phi) and superoxide dismutase (Sod), following starch gel electrophoresis. In the material examined, Est-1, Est-2, Est-3, Got, ldh, Lap-2, Odh, Pgm-1, Pgm-2 and Sod were segregating for two or more alleles; unique alleles at the Est-1, Got and Sod loci produced species-specific phenotypes in A. melas (Theo.), species C and species D, respectively. The further sampling of A. merus Dön, populations supported the presence of a unique SOD phenotype by which this species can also be identified. Of the other enzyme systems examined, no activity following electrophoresis was detected for aldolase and fructose-1,6-diphosphatase, and the resolution of acid and alkaline phosphatase, glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, malic dehydrogenase and xanthine dehydrogenase was too poor under the particular electrophoretic conditions for genetic analyses of the enzyme phenotypes.


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