Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
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Drug
Enzyme
Compound
Query: UMLS:C0023890 (
cirrhosis
)
42,195
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Microsomal Na+,K+-ATPase isolated from the renal cortex of rats with CCL4-induced
cirrhosis
(
CIR
) showed a higher specific activity than the enzyme obtained from control rats (COR). Kinetic studies showed a lower K0.5 for ATP (0.08 +/- 0.03 vs. 0.24 +/- 0.04 mM; p less than 0.05), a lower Na+ activation constant (9.6 +/- 1.5 vs. 19.0 +/- 1.7 mM; p less than 0.05), and a higher K+ activation constant (1.2 +/- 0.1 vs. 0.6 +/- 0.1 mM; p less than 0.05) for
CIR
. The optimal pH of the enzyme was 0.5 units higher in
CIR
than COR. The fluorescence of eosin-treated enzymes indicated a higher ratio of E1/E2 forms of Na+,K+-ATPase in
CIR
. The K+-activated
p-nitrophenylphosphatase
(pNPPase) activity of the enzyme was lower in
CIR
than COR rats (1.5 +/- 0.1 vs. 2.2 +/- 0.1 mU/mg; p less than 0.05). Dialysing (24 h) COR microsomes reproduced most of the changes observed in
CIR
enzymes (kinetics, optimal pH, and eosin fluorescence). Lyophilized dialysate of COR, but not of
CIR
microsomes, inhibits Na+,K+-ATPase activity. These results suggest that a dialysable inhibitor modifies the Na+,K+-ATPase activity in the kidney of COR which is almost absent in that of
CIR
. The absence of this factor may lead to the overall inability to excrete Na+ in the cirrhotic state.
...
PMID:Absence of an endogenous regulator of Na+,K+-ATPase activity in the tissues of cirrhotic rats. 283 57
