Pattern of methionine adenosyltransferase isoenzyme expression during rat liver regeneration after partial hepatectomy.
The present report investigates the pattern of expression of liver-specific and extrahepatic methionine adenosyltransferase (MAT) isoenzymes in regenerating rat liver after partial hepatectomy. The results show that there is a switch in the expression of these isoenzymes that is coincident with maximal cell proliferation in the remaining liver lobes. Extrahepatic MAT levels increase about three times 4 h after hepatectomy, reaching a maximum 36 h later. This is accompanied by a rapid and transient increase in total MAT activity and levels of related metabolites S-adenosyl-L-methionine and S-adenosyl-L-homocysteine. Liver-specific MAT levels are reversibly down-regulated within 24-48 h post surgery. Our results indicate that MAT isoenzyme expression is tightly regulated during liver regeneration after two-third hepatectomy. The implications of these observations for evaluation of the degree of liver regeneration are briefly discussed.
Frago
L M
LM
Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Cientifícas, Madrid, Spain.
Giménez
A
A
Rodriguez
E N
EN
Varela-Nieto
I
I
D000818:Animals; D004789:Enzyme Activation / Q000235:genetics / Q000502:physiology; D006498:Hepatectomy; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008099:Liver / Q000201:enzymology / Q000502:physiology; D008115:Liver Regeneration; D008297:Male; D008716:Methionine Adenosyltransferase / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D007527:Isoenzymes; D012333:RNA, Messenger; D008716:Methionine Adenosyltransferase