Influence of estradiol and gestagens on oxidative stress in the rat uterus.
OBJECTIVE
We studied the effect of ovariectomy, estradiol (E2), and E2 + medroxyprogesterone (MPA) on the Wistar rat uterus.


METHODS
We used 15 adult female rats. The study was divided into the following four stages: (a) extirpation of the upper half of the left hemi-uterus (basal state) and ovariectomy; (b) animals were maintained for 15 days without treatment, performance of a new laparotomy, and extirpation of the remaining left hemi-uterus (OVX state); (c) beginning of E2 replacement therapy (ERT) (8 microg/day) for 15 days, followed by extirpation of the upper half of the right hemi-uterus (ERT state); and (d) the administration of E2 was continued, and oral treatment with MPA was begun (20 microg/day) to last for a further 15 days. At the end of the combined hormone replacement therapy (HRT) the remaining right hemi-uterus was extirpated (HRT state). At the end of each intervention, the plasma concentrations of E2 and PRG were measured.


CONCLUSIONS
The ovariectomy significantly reduced the malonaldehyde (MDA) levels (P < 0.0008) and catalase activity (P < 0.0006). The ERT very significantly (P < 0.0033) raised the catalase and MDA levels; these significance levels were maintained after the Bonferroni method was applied (overall error 5%). The HRT reduced the levels of MDA and catalase, but not significantly after the Bonferroni test was applied.Conclusions. Uterine oxidative stress is increased by E2, resulting in a significant increase in MDA. This may be modulated in part by the catalase activity. Although it cannot be confirmed categorically, MPA seems to intervene by decreasing the said oxidative stress.
Gómez-Zubeldia
M A
MA
Department of Nursing, School of Medicine, University of Extremadura, Avenida Elvas s/n, 06071 Badajoz, Spain.
Corrales
S
S
Arbués
J
J
Nogales
A G
AG
Millán
J C
JC
D000818:Animals; D002374:Catalase / Q000378:metabolism; D004347:Drug Interactions; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D008525:Medroxyprogesterone / Q000494:pharmacology*; D010052:Ovariectomy; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*
D004958:Estradiol; D008315:Malondialdehyde; D002374:Catalase; D008525:Medroxyprogesterone