title: Isatin (2,3-dioxoindole): a competitive inhibitor of Na(+)-dependent lysine uptake in rat instestine.
abstract: Isatin (2,3-dioxoindole) competitively inhibited (27-40%) Na(+)-dependent L-lysine uptake in rat intestine. The value of Kt was increased from 3.04 mM in control to 5.88 mM in presence of 10 mM isatin. Effect of isatin on the Na(+)-independent amino acid uptake was insignificant (12-18%). The inhibitory constant (Ki) was 2.8 mM under these conditions. The observed inhibition was unaffected by -SH group reacting agents. Isatin (1-10 mM) inhibited Na+, K(+)-ATPase activity in intestine in vitro, the maximum inhibition (66%) being at 10 mM isatin concentration. But the drug had no effect on enzyme activity under in vivo conditions.
authors.affiliation: Department of Biochemistry, Panjab University, Chandigarh, India.
authors.forename: M L
authors.initials: ML
authors.lastname: Gargari
authors.forename: R C
authors.initials: RC
authors.lastname: Bansal
authors.forename: S N
authors.initials: SN
authors.lastname: Mahmood
authors.forename: A
authors.initials: A
authors.lastname: Mahmood
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D007413:Intestinal Mucosa / Q000378:metabolism*; D007510:Isatin / Q000494:pharmacology*; D007700:Kinetics; D008239:Lysine / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013439:Sulfhydryl Reagents / Q000494:pharmacology
chemical_list: D013439:Sulfhydryl Reagents; D007510:Isatin; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D008239:Lysine