Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Freshly isolated rabbit proximal tubules (PT), confluent primary rabbit proximal tubule cultures (PTC) and LLC-PK1 cells were characterised. Brushborder enzyme activities were lower in PTC than in LLC-PK1: ratios were 0.026 for alkaline phosphatase (AP), 0.458 for alanine aminopeptidase (AAP) and 0.514 for gamma-glutamyl transpeptidase (GGT). PT/PTC ratios were 79.7 for AP, 7.96 for AAP and 3.45 for GGT. Specific activities of hexokinase (HK) and lactate dehydrogenase (LDH) were high in cultured cells as compared to PT: PT/PTC ratios were 0.063 and 0.033, while PTC/LLC-PK1 ratios were 0.406 and 1.19 for HK and LDH respectively. PTC/LLC-PK1 ratios were 2.21 for Na/K ATPase, 2.07 for succinate dehydrogenase, 1.12 for cathepsin B, 0.607 for N-acetyl-beta-D-glucosaminidase and 8.98 for glutathione-S-transferase. Adenylate cyclase response to parathormone (PTH), was similar in PTC and PT, but stimulated/basal ratios were higher in PT than in PTC. LLC-PK1 cells were stimulated by thyrocalcitonin (SCT), arginin-vasopressin (AVP) and PTH; stimulated/basal ratios ranked AVP greater than PTH greater than SCT. Differences between both types of cultures affect the choice of in vitro model for nephrotoxicity studies.
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PMID:Adenylate cyclase responses and biochemical characterization of primary rabbit proximal tubular cell cultures and LLC-PK1 cells. 228 70

This study describes a method for the separation of distal cell populations based on the sequestration of proximal cells on immunoadsorbent columns (CNBr-activated Sepharose 6MB) bound with three brush-border monoclonal antibodies (S6-Mab). A high yield of isolated cell suspension from rabbit kidney cortex was prepared by mechanical dissociation after perfusion and incubation of the kidneys with 10(-3) M EDTA. The sequestration of the proximal cells was achieved in two sequential chromatographic steps. About 92% of the applied cells were first retained on an S6-Mab column after a 60-min stationary stage and the unbound cells were submitted by direct flow to a second S6-Mab column. In such conditions, 8 X 10(6) cells were recovered when starting with 331 X 10(6) cortical cells. The efficiency of the proximal cell depletion process was confirmed by an 80% decrease in brush-border enzymes, a very low phosphoenolpyruvate carboxykinase activity, and absence of cells bearing long microvilli, as ascertained by electron microscopy. This immunodepleted cell population presented the enzymatical characteristics of cells from the more distal segments. As compared with the initial cell suspension, these cells exhibited higher hexokinase (2.3 times), succinate dehydrogenase (1.5 times), and Na+-K+-ATPase (2.6 times) activities. In addition, adenylate cyclase activities remained sensitive to parathormone, arginine vasopressin, and isoproterenol. The functional capacity of these immunodepleted cells was assessed by an almost complete exclusion of eosin dye, a low Na+ and high K+ intracellular content, and a high respiratory rate of oxygen consumption. In conclusion, this immunoselective process makes it possible to obtain subpopulations of renal cortical cells possessing the main characteristics of the distal, connecting, and collecting cells for physiological and metabolic studies.
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PMID:Indirect immunoselection of late distal cell populations from rabbit kidney cortex. 351 19

Skeletal muscle biopsies were performed on 12 healthy sedentary subjects and on 22 non-dyalized chronic renal failure patients (CRF) on a free diet and after overnight fasting. Parathormone, glucagon and insulin were determined at the same time of biopsies. CRF patients showed significantly low ATP and creatine phosphate levels. Regarding enzyme activities, a high hexokinase Vmax was found, while the pyruvate kinase activity was lower than in the control group. For the tricarboxylic acid cycle, citrate synthase, succinate dehydrogenase and malate dehydrogenase activities were higher; total NADH cytochrome c reductase activity was also high, while cytochrome oxidase activity was slightly lower. Both alanine aminotransferase and aspartate aminotransferase activities were considerably high in comparison with the control group. In conclusion, our study revealed a hypermetabolic TCA cycle, but impaired oxidative phosphorylation, which partly explained the reduced ATP concentration. Excessive protein intake and hormonal derangements may play a role in these metabolic changes.
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PMID:Altered muscle energy metabolism in post-absorptive patients with chronic renal failure. 924 94