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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sammo plant which is traditionally used in Egypt for the treatment of diabetes mellitus, was administered at low and high levels (4% and 8% respectively at the expense of starch) to adult male alloxanized albino rats, to study its effect on energy metabolism. Adenosine-5-triphosphate (ATP) in the brain (B), liver (L) and kidneys (K) organs of alloxanized rats was significantly lowered compared with the negative control. On the other hand, adenosine-5-diphosphate (ADP) and adenosine-5-monophosphate (AMP) contents in the same organs were elevated markedly. In this connection myokinase activity in cytoplasmic and mitochondrial fractions of B, L and K organs was stimulated at control. Also, the activities of some fundamental enzymes of the oxidative pentose phosphate pathway i.e. glucose-6-phosphate dehydrogenase (G-6-PD) and 6-phospho-gluconate dehydrogenase (6-PGD) in cytoplasmic and mitochondrial fractions of the same organs were markedly increased. Administration of Sammo at low and high levels reduced the consumption of ATP in B, L and K organs relative to positive control. Whereas, ADP and AMP contents were relatively reduced. Also, myokinase activity in the same organs were relatively inhibited. The activity of G-6-PD and 6-PGD in cytoplasmic and mitochondrial fractions of the same organs were also decreased relative to the positive control.
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PMID:The effect of sammo administration on some fundamental enzymes of pentose phosphate pathway and energy metabolites of alloxanized rats. 157 54

Streptozotocin diabetes induces a 4-fold increase in the maximal velocity of inner medullary aldose reductase as determined in vitro but increases sorbitol synthesis in intact inner medullary collecting duct (IMCD) cells only 1.3-fold. In order to resolve this discrepancy we investigated the importance of intracellular factors in controlling the role of cellular sorbitol synthesis. These factors include glucose concentration, sorbitol concentration, the activity of the NADPH-regenerating pentose phosphate pathway, intracellular NADP and NADPH content, and intracellular reduced (GSH) and oxidized glutathione (GSSG). It was found that the apparent Km of cellular sorbitol production for glucose was identical in control and diabetic rats (56 +/- 18 vs. 59 +/- 14 mmol/l D-glucose), whereas Vmax increased by 31% in diabetes. In inner medullary collecting duct cells of diabetic rats containing 146 +/- 5 mumol sorbitol/g protein, sorbitol synthesis was slightly lower (-15%), compared to cells which had been sorbitol-depleted prior to the experiment (87 +/- 4 mumol sorbitol/g protein). However, no inhibitory effect of sorbitol (up to 200 mmol/l) was observed on aldose reductase activity in vitro. In diabetic rats the content of NADPH was about 32% lower than in the control rats (3.8 +/- 0.3 vs. 5.6 +/- 0.4 mumol/g protein) and the ratio of NADPH/NADP was decreased from 25.6 +/- 5.1 to 8.6 +/- 1.7. In homogenates of the inner medulla the activity of 6-phospho-gluconate dehydrogenase (EC 1.1.1.43) was identical in both experimental groups, so the pentose phosphate shunt seems to be unaltered. GSH content in diabetic rats was also diminished (4.02 +/- 0.67 mumol/g protein vs. 7.41 +/- 0.5 mumol/g protein) and the GSH/GSSG ratio fell from 92.6 to 57.4. In enzyme tests in vitro an apparent Km of 7.3 +/- 1.9 mumol/l of the aldose reductase for NADPH was found; NADP acted as competitive inhibitor with an apparent K(i) of 183 +/- 31 mumol/l. Aldose reductase activity was also found to be strongly inhibited by the SH-group reagent p-chloromercurybenzoesulfonate (apparent K(i) = 0.85 x 10(-6) mol/l). Combining the results obtained on the properties of the aldose reductase in vitro and the observation made in the intact cells, the investigators suggest that the decrease in NADPH/NADP ratio, as well as changes in the redox state in the cells of diabetic animals, can play a significant role in the control of sorbitol synthesis.
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PMID:Control of sorbitol metabolism in renal inner medulla of diabetic rats: regulation by substrate, cosubstrate and products of the aldose reductase reaction. 824 Dec 88