Possible Interaction: Hydrogen Peroxide and Progesterone

“ Progesterone production by luteinized granulosa cells was significantly inhibited by H2O2.”

“This study indicated that H2O2 inhibited PG production by GCs via cAMP pathway, protein kinase C (PKC) and the activities of intracellular calcium, P450scc and StAR protein.”

“Here we report that progesterone and various synthetic steroids with progestin potencies (norethisterone acetate, MPA, and Tibolone) counteract cell growth induced by hydrogen peroxide (H(2)O(2)), through a potent induction of catalase activities, in breast cancer cells and normal human epithelial breast cells.”

“After exposure to hydrogen peroxide , cells grown with oestradiol alone or with both oestradiol and progesterone showed significantly decreased viability compared to cells grown in medium without added hormones.”

“On the basis of the results obtained, we propose that the inhibition of progesterone biosynthesis by naturally occurring hydroperoxides may contribute to the development of preeclampsia.”

“This suggests that inhibition of progesterone synthesis from cholesterol by hydroperoxide may be ascribed to its effect on the desmolase activity of cytochrome P-450SCC in placental mitochondria.”

“ H2O2 treatment (1.0-100 microM) of mid and late luteal cell cultures elicited a dose-dependent decrease in basal progesterone production.”

“However, treatment of mid luteal cells with a low concentration of H2O2 (0.01 microM) significantly stimulated progesterone secretion (P < 0.05).”

“In addition, H2O2 (100 microM) markedly inhibited human chorionic gonadotropin (hCG)-stimulated progesterone and estradiol secretion.”

“ Progesterone and estradiol production stimulated by dibutyryl cAMP were significantly inhibited by H2O2 (P < 0.05).”

“The addition of H2O2 (0.1-100 microM) to hCG-stimulated luteal cell cultures elicited a decrease in cAMP concentration (P < 0.05) and in the specific binding of radiolabeled hCG by luteal cells.”

“ H2O2 dose-dependently inhibited progesterone production (ED50, 50-100 microM) in the absence or presence of hCG and blocked hCG-stimulated cAMP accumulation.”

“Inhibition of progesterone synthesis by H2O2 was near maximal within 5 min, whereas inhibition of cAMP accumulation was not evident until 60 min.”

“ Progesterone production stimulated by 8-bromo-cAMP, 22-hydroxycholesterol, and pregnenolone was inhibited by H2O2 as was androstenedione-dependent estradiol production.”

“These findings indicate that H2O2 blocked progesterone synthesis by inhibition of cholesterol side-chain cleavage cytochrome P450, 3 beta-hydroxysteroid dehydrogenase, aromatase, and/or 17 beta-hydroxysteroid dehydrogenase.”

“ Progesterone at placental tissue concentrations (5-20 micrograms/ml) markedly increases in vitro PMA-stimulated O-2 and H2O2 production by human cultured monocytes.”

“Exogenous GSH decreased the content of H2O2 of culture medium pretreated by progesterone combined with H2O2 or progesterone alone.”

“Further study demonstrated that progesterone increased H2O2 concentration of culture medium which may contribute to NO synthesis.”

“It is shown, that progesterone in hormonal concentrations boosts biosynthesis of NO and H2O2 , in comparison with estrone, both in real time of signalling events in the cells (5-30 s), and at long-term action (1-3 h) more effectively.”