dinoprost and 25-hydroxycholesterol

To investigate the involvement of 8-iso-PGF(2alpha) and 25-hydroxycholesterol (25-OH-Chol) in the pathophysiology of endometriosis.. Observational case-control study using enzyme immunoassay and high-performance liquid chromatography (HPLC).. Postgraduate Institute of Medical Education and Research.. Forty-five women undergoing laparoscopy (n = 25), laparotomy (n = 19), or tubal ligation (n =1).. Venipuncture and laparoscopic peritoneal fluid (PF) collection.. The levels of 8-iso-PGF(2alpha) were determined both in urine and PF of all the patients using enzyme immunoassay. The levels of 25-OH-Chol were determined by using reversed phase HPLC both in the plasma and PF samples. Oxidative damage to DNA was assessed by agarose gel electrophoresis.. Significantly increased levels of 8-iso-PGF(2alpha) were observed both in urine and PF of women with endometriosis compared with control women. Similarly, higher levels of 25-OH-Chol were observed both in plasma and PF of patients compared with controls and the difference was statistically significant. A clear-cut tailing pattern was observed in DNA of patients with endometriosis, indicating significant DNA damage.. Our observations implicate oxidative stress in the pathophysiology of endometriosis. For the first time, we demonstrate that 8-iso-PGF(2alpha) and oxysterols (the known promoters of steroidogenesis) might be the culprits in this disease.

Topics: Adult; Ascitic Fluid; Biomarkers; Case-Control Studies; Dinoprost; Endometriosis; Female; Humans; Hydroxycholesterols; Young Adult

Prostaglandin F2 alpha (PGF2 alpha) inhibits lipoprotein-stimulated progesterone production by bovine luteal cells in vitro and the objective of this study was to localize the site of action of PGF2 alpha. Cultured bovine luteal cells were treated with PGF2 alpha for seven days, and then with either lipoproteins or 25-hydroxycholesterol in the presence of aminoglutethimide (which inhibits cholesterol side-chain cleavage) for the final 48 h. The effects of PGF2 alpha on progesterone production, cellular cholesterol content, mitochondrial cholesterol content and cholesterol side-chain cleavage activity were determined. As expected, PGF2 alpha inhibited (P less than 0.05) lipoprotein-stimulated progesterone production. However, PGF2 alpha did not inhibit low-density lipoprotein-stimulated, or high density lipoprotein-stimulated, increases in cellular cholesterol (P less than 0.05) or inhibit lipoprotein-induced increases in mitochondrial cholesterol content (P less than 0.05). Additionally, cholesterol content of mitochondria increased (P less than 0.05) in the presence of PGF2 alpha alone. To determine if the PGF2 alpha-induced inhibition of steroidogenesis occurred at, or after, the side-chain cleavage reaction, we treated cells with the readily diffusable sterol, 25-hydroxycholesterol. Prostaglandin F2 alpha did not inhibit 25-hydroxycholesterol-stimulated progesterone production (P less than 0.05). Prostaglandin F2 alpha may therefore exert its luteolytic effect at a site after cholesterol transport to the mitochondria but before cholesterol side-chain cleavage.

Topics: Aminoglutethimide; Animals; Cattle; Cells, Cultured; Cholesterol; Corpus Luteum; Depression, Chemical; Dinoprost; Female; Hydroxycholesterols; Lipoproteins; Luteolysis; Mitochondria; Progesterone

Fetal calf serum is able to activate arachidonic acid release from phospholipids in NRK 49F cells. We showed that this phenomenon can be potentiated by adding oxysterols to the culture medium. The oxysterol effect was dose-dependent and was not observed in the absence of fetal calf serum. Greater amounts of prostaglandin E2 and prostaglandin F2 alpha were released into the medium in the presence of oxysterols without apparent modification of the cyclooxygenase activity. The most effective oxysterols, in descending order, were the following: calcitriol greater than 7 alpha-hydroxycholesterol greater than 7 beta-hydroxycholesterol greater than 25-hydroxycholesterol. Cholesterol and 7-ketocholesterol were unable to activate phospholipase activity. The mechanism of this activation by oxysterols is still unknown.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Animals; Arachidonic Acid; Arachidonic Acids; Blood; Carbon Radioisotopes; Cattle; Cell Line; Chromatography, Thin Layer; Dinoprost; Dinoprostone; Fetal Blood; Hydroxycholesterols; Hydroxyeicosatetraenoic Acids; Kinetics; Phospholipids; Prostaglandin D2; Prostaglandins; Prostaglandins A; Prostaglandins D; Prostaglandins E; Prostaglandins F

Although estradiol is the established luteotropic hormone in the rabbit, the corpus luteum also contains a luteinizing hormone (LH)-activated adenylate cyclase system and cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase, which suggests that LH and cAMP may play a physiological role in regulating luteal progesterone production. The present study examined whether human chorionic gonadotropin (hCG) and cAMP derivatives stimulate progesterone production by dispersed rabbit luteal cells in static and perifusion incubations. Results of this study show that progesterone production by rabbit luteal cells is significantly stimulated (p less than 0.05) by hCG concentrations at or greater than 0.1 IU/ml or by dibutyryl cAMP concentrations at or greater than 5 mM. Both agents produce maximal stimulations of approximately 4-fold. However, neither prostaglandin E2 or F2 alpha at concentrations of 0.1-3.0 micrograms/ml altered progesterone secretion. When luteal cells were incubated with maximal concentrations of hCG and lipoproteins together, the resultant progesterone secretion was additive. This suggests that the effects of hCG and lipoprotein are independent. Both responses could be blocked completely by cycloheximide (10(-4) M), and thus appear to be dependent on protein synthesis. The cholesterol derivative 25-hydroxycholesterol (20 micrograms/ml) partially overcame the steroidogenic block by cycloheximide, suggesting that transport of cholesterol, regardless of its origin, into mitochondria was an essential protein-mediated event in these cells. Inhibition of the side-chain-cleavage enzyme by aminoglutethamide blocked progesterone production by rabbit luteal cells in vitro. Although estradiol may dominate in the regulation of luteal progesterone production physiologically, this study clearly demonstrates that potential mechanisms do exist in the rabbit corpus luteum for cAMP-mediated stimulation of progesterone production in the rabbit.

Topics: Animals; Bucladesine; Cells, Cultured; Cholesterol Side-Chain Cleavage Enzyme; Chorionic Gonadotropin; Corpus Luteum; Cycloheximide; Dinoprost; Dinoprostone; Female; Hydroxycholesterols; Kinetics; Lipoproteins, LDL; Progesterone; Prostaglandins E; Prostaglandins F; Protein Biosynthesis; Rabbits