Involvement of sulfhydryl groups in time-dependent changes of diaphragm acetylcholinesterase activity by monovalent (Na+, Li+) cations.
Acetylcholinesterase (AChE) activity, as a function of time, showed a concentration dependent increase induced by NaCl, followed by a plateau. In the presence of LiCl, the enzyme activity, before its stabilization, presented an increase, followed by a decrease to a minimum value. Sucrose increased the initial rise and the final value of AChE activity and caused no changes, as a function of time, in the absence of cations. Moreover sucrose eliminated AChE activity decrease caused by LiCl. 2-mercaptoethanol induced considerable and steady increase of AChE activity, in the presence or absence of cations or sucrose and no changes, as a function of time. These results show an activating and protecting effect of sucrose on AChE and the possible involvement of sulfhydryl (SH) groups in the time-dependent changes of the enzyme activity induced by Na+ or Li+.
Department of Experimental Physiology, University of Athens, Medical School, Greece.
P
P
Kouniniotou-Krontiri
S
S
Tsakiris
G M
GM
Hadjigeorgiou
D000110:Acetylcholinesterase / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D002412:Cations; D003964:Diaphragm / Q000201:enzymology; D007700:Kinetics; D008094:Lithium / Q000494:pharmacology*; D008623:Mercaptoethanol / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000494:pharmacology*; D013438:Sulfhydryl Compounds / Q000378:metabolism / Q000494:pharmacology*
D002412:Cations; D013438:Sulfhydryl Compounds; D008623:Mercaptoethanol; D008094:Lithium; D012964:Sodium; D000110:Acetylcholinesterase