An increased concentration of acid-soluble thiols appear ?:o be involved ha ce~ div:mio~ and ha turnout formation {1 ]. This cou.]d be re]a~ed w~th oxidation--ied,uc£~on of glulathSone w,h]ch ~s probably a steadysta~e dependent, ira par~, on glnta~one zeductas~ and glutathione perox~dase activities ~2-4].The present communication compares the activities of these enzymes in rat hepatomous ]h, er, 5nduced by diethy!nitros~.mine [5], with control ra~ liver and show~ that GSSG reductase ]s increased and GSH peioxi,dase ~ decreased iv the l~er of ram treated with dieflay]nJtrosamine. 5"he e£feet is sex independent.
Materials and methods
J. MaterialsAll the chemicals used w :re of the purest grade available. GSH, GSSG, NADPH and yeast glntaflfione reductase were obtained from C.F. Boehfinger and Soehne GmbH, Mann:heim, Germany. All the other reagents u~ed were supF]~ed by British Drug Houses, L~d., Poole, Dorset, ,Great Britain.
Animals and diemWistar rats were from the Sheffield University Anianal House colony and were fed ad lib~um with Ox~od die~ 86 (Herbert C. Style~ Ltd., Bew dley, Worts.).
Dielh)qnitzosffrai~e indue;ion of hver turnoutswa~ carried out adding die~y]ni*rozam :no to ~he dfin~ng wate~ (50 rng/!~) of 20 rats (l 0 males and 10 females) for about 4 months. After th :; t~ne ~e animals started dy'mg and for this reason the remaining treated rats and the control rats were killed at once for the exp~.r:..arutal measurements. The l_vers were removed an~ after pleparation of microscopic section for ]bght microscopy they were kept in the deep freeze. In/he Ik, ers of the rats treated va~ diethy]niires ,amine there were large amounts of aaedp~a~t~c fo=i and a few areas of necroMs w)fich were absent in V.he controls. The average w~aght of the control rats was 390 -+ 25 g for males and 252 +-% 23 g for females and that of the treated rats was 2~0 4---30 g and 1~;0 ---17 g, respecdwely. Thus the treated rats were on average about 70% of the weight of control ra~.
Male rats weighing