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

The effects of three Class I antiarrhythmic agents, quinidine (Class 1A), lidocaine (Class 1B) and encainide (Class 1C) on the Mg2(+)-dependent, Na+/K+ activated adenosine triphosphatase were compared with those of ouabain in microsomal preparations of the guinea pig heart. Lidocaine and quinidine inhibited the ATP-hydrolysis by the Na(+)-K(+)-ATPase in a concentration-dependent fashion similar to that of ouabain. The concentrations for half maximal inhibition of the enzyme activity were 4.1 +/- 0.7 mM for lidocaine and 0.46 +/- 0.12 mM for quinidine. Encainide exhibited stimulatory tendency at pharmacological concentrations, enhancing the enzyme activity by 2.5% at 1.0 microM and 25% at 1.0 mM. These results show that the Class I antiarrhythmic drugs may influence the Na(+)-K(+)-ATPase activity in different ways.
 ...
PMID:Effects of quinidine, lidocaine and encainide on guinea pig myocardial Na(+)-K(+)-ATPase activity. 216 76

Subcellular vesicles present in brain microsomal fraction take up calcium by an ATP-dependent process which is probably one of the mechanisms involved in the regulation of free calcium ions concentratioon in the cytosol of nerve cells. The experiments described in this paper were designed to test the effect of local anesthetics on this transport system since it is known that cytoplasmic calcium concentration interferes with nerve excitability and conduction and transmitter release. It was found that tetracaine increases the rate of calcium uptake in the range of 0.5 to 3 mM and inhibits calcium uptake in the range of 4 to 7 mM. Lidocaine and procaine increase calcium uptake in the range of 5 to 30 mM and inhibit calcium uptake in the range of 40 to 70 mM. The effects of local anesthetics were also tested on th ATP hydrolysis coupled with calcium uptake and on the ATP in equilibrium Pi exchange which represents the reverse reaction of this transport system. It was found that three local anesthetics inhibit ATP in equilibrium Pi exchange in concentrations which increase calcium uptake and inhibit ATP hydrolysis in concentrations which inhibit calcium uptake. These findings indicate that the enhancement of calcium uptake by the lower concentrations of local anesthetics is due to a decrease of the reverse reaction, whereas inhibition of calcium uptake by the higher concentrations of local anesthetics is due to the blockage of the transport adenosine triphosphatase.
 ...
PMID:The mode of action of local anesthetics on the calcium pump of brain. 740 Sep 68