Biochemical parameters in various sections of bovine corpora lutea graviditatis during the course of pregnancy

The enzyme activities of glutathione peroxidase (GPO) with cumenehydroperoxide (cumene-OOH) and H2O2 as substrates, glutathione-S-transferase (GSH-S-T) with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate, phosphofructokinase (PFK) and succinate dehydrogenase (SuDH) were determined for months 1 through 9 of pregnancy in the basal and peripheral sections of the corpora lutea graviditatis of Holstein-Frisean cows. The concentration of reduced glutathione (GSH) was simultaneously measured in these tissue sections. Substantial topographical differences were apparent in the enzyme activities. GPO and GSH-S-T showed activity differences during the course of pregnancy. During the 2nd month of pregnancy, minimal values for the activity of cytoplasmic GPO were observed in the basal areas. The cytoplasmic GPO in the peripheral areas displayed a contrasting dynamic with maximal values during the 6th month. GSH-S-T activities in basal and peripheral tissues appeared similar. GPO activities with H2O2 as substrate, likewise, displayed similar courses of activity in both tissue localizations. SuDH was more active in the peripheral than in the basal area. The activity of PFK displayed just the reverse course. The concentration of GSH in the peripheral area was not higher than in basal area.