Possible Interaction: Phospholipids and Progesterone

“The systemic (intravenous) administration of phospholipids also weakens the progesterone block and results in a premature evolution of uterine activity.”

“In comparison, the effect of progesterone on total lipids or phospholipids was less marked.”

“While 17 beta-estradiol did not influence this reaction, progesterone suppressed the removal by apoA-I of both cholesterol and phospholipid , with the extent of the inhibition more for cholesterol than phospholipid.”

“However, in 10 out of 11 positively responding to EGF adenocarcinomas progesterone inhibited the EGF-dependent activation of 32P incorporation into the phospholipids already on the 15th min after its addition to the cells.”

“The results obtained suggest that the EGF-dependent activation of intracellular phospholipid turnover is under the negative control of progesterone.”

“ Progesterone in a final concentration of 10(-7) … twofold decrease of 32P incorporation into phospholipids (phosphatidylcholine and phosphoinositides) in 85% of the uterine adenocarcinomas where the progesterone receptor (PR) content was more … and only in 30% of the tumors where the PR content was less than 100 nmol/kg.”

“ PL (5-11 pmol phosphorus/ml) decreased (up to 0.5-times the control) progesterone synthesis, production of superoxide and levels of P450 cholesterol side chain cleavage (P450 scc), 3beta-hydroxysteroid dehydrogenase and COX-2 mRNA.”

“Estradiol increased PL-content, incorporation of (1-14C)-PA into the PL , while progesterone inhibited E-dependent effect, Gonadotrophin-induced ovulation provoked increase in uterine PL-content and remained a stimulatory signal for incorporation of (1-14C)-PA.”

“Prostaglandin E or F2 alpha and alterations in tissue phospholipid composition inhibited progesterone release, and inhibition was independent of the series of prostaglandin produced.”

“This phospholipid preparation, at a concentration of 0.5-1 mg/ml, greatly reduces the inhibition of this enzyme caused by progesterone.”

“ Progesterone induced a transient increase in the incorporation of [3H]methyl groups into phospholipids of Xenopus oocytes followed by a rise in 45Ca2+ uptake.”