Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Potassium-stimulated p-nitrophenylphosphatase (K+-pNPPase) activity was investigated in rat somatosensory cortex where 64-88% of enzymatic activity survived 5-10 min of fixation with 3% formaldehyde in 0.1 M cacodylate buffer, pH 7.4. Potassium-stimulated activity was inhibited by 1-10 mM ouabain. Levamisole (1.7 mM) inhibited brain alkaline phosphatase activity, facilitating the detection of K+-pNPPase activity. Strontium (10-20 mM) inhibited enzymatic activity by 38-75%. In parallel histochemical studies reaction product was found in strata, with cortical layers 2, 3, 4 and the outer portion of 5 containing the heaviest deposits. Highly reactive, vertically oriented, large diameter fibers were seen as groups between the outer portion of layer 5 and the pail surface. These fibers apparently arborize in the superficial layers. Smaller fibers were also positive and were oriented in various planes. The highest density of smaller, positive fibers occurred in layers 2 through 5. All positive fibers appeared to be axons or dendrites. Reaction product was not heavily concentrated in neuron perikarya or in glial elements. Sections did not contain reaction product when incubated in media lacking K+ or containing ouabain. The convergence of data from parallel histochemical and biochemical approaches supports the conclusion that the reactivity localized in the cerebral cortex represented the site of K+-pNPPase, a known component of the Na+,K+-adenosine triphosphatase complex. Neuronal processes demonstrated the highest enzymatic activity and may be most important in the active transport of Na+ and K+ in somatosensory cortex.
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PMID:Histochemical localization of potassium-stimulated P-nitrophenylphosphatase activity in the somatosensory cortex of the rat. 18 89

To show adenylate cyclase (AC) activity in rat calvaria, it is necessary first to decalcify the specimen. In hard tissues, several enzymes (adenosine triphosphatase (ATPase), alkaline phosphatase (APase), adenylate cyclase (AC) and perhaps pyrophosphatase (PPiase) are able to degrade adenosine triphosphate (ATP). The presence of sodium fluoride (NaF) in the incubation medium reduces the quantity of precipitate formed, compared to that observed using a NaF-free incubation medium. Levamisole, used under the same conditions, gives similar results. Possibly NaF inhibits pyrophosphohydrolase and/or phosphatases which mask the AC activity. Adenylylimidophosphate (AMP-PNP), which is a specific AC substrate, confirms the results obtained with ATP. AC activity is demonstrated cytochemically in the osteoblast and preosteoblast membranes, at the junction between two osteoblasts and along the cytoplasmic processes of the osteoblast which penetrate into the osteoid matrix. The osteocytes never show a precipitate, except those which present some osteoblastic features and then only on the membrane facing the osteogenic layer. An intracellular reaction is also evident and is discussed. Parathyroid hormone (PTH) does not reveal new sites of AC activity but increases the quantity of precipitate observed.
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PMID:An attempt at localizing adenylate cyclase in rat calvaria. Influence of sodium fluoride and parathyroid hormone. 700 93