Lipid peroxidation in the peritoneal fluid of infertile women with peritoneal endometriosis.

OBJECTIVE: To assess the level of lipid peroxidation in the peritoneal fluid of infertile women with peritoneal endometriosis and of fertile disease-free controls. STUDY DESIGN: Level of lipid peroxidation (malondialdeyde, malondialdeyde with copper addition, and cholest-3,5-dien-7-one) was measured in the peritoneal fluid obtained from 21 women with endometriosis-related infertility and from 21 fertile women having tubal ligation. RESULTS: : The level of lipid peroxidation did not differ significantly (P > 0.05) according to the stage of endometriosis. The level of lipid peroxidation (malondialdeyde, malondialdeyde with the addition of copper, and cholest-3,5-dien-7-one) did not differ significantly (P > 0.05) between patients with endometriosis-related infertility (0.07 nmol/ml, 0.34 nmol/ml, 0.24 microg/ml, respectively) and disease-free controls (0.04 nmol/ml, 0.21 nmol/ml, 0.25 microg/ml, respectively). CONCLUSION: The level of lipid peroxidation did not differ between women with endometriosis-related infertility and fertile disease-free controls, suggesting that increased reactive oxygen species may not be one of the factors responsible for compromised fertility in patients with endometriosis.

Estrogen replacement therapy and cardioprotection: mechanisms and controversies.

Epidemiological and case-controlled studies suggest that estrogen replacement therapy might be beneficial in terms of primary prevention of coronary heart disease (CHD). This beneficial effect of estrogens was initially considered to be due to the reduction of low density lipoproteins (LDL) and to increases in high density lipoproteins (HDL). Recent studies have shown that estrogens protect against oxidative stress and decrease LDL oxidation. Estrogens have direct effects on the arterial tissue and modulate vascular reactivity through nitric oxide and prostaglandin synthesis. While many of the effects of estrogen on vascular tissue are believed to be mediated by estrogen receptors alpha and beta, there is evidence for 'immediate non-genomic' effects. The role of HDL in interacting with 17beta-estradiol including its esterification and transfer of esterified estrogens to LDL is beginning to be elucidated. Despite the suggested positive effects of estrogens, two recent placebo-controlled clinical trials in women with CHD did not detect any beneficial effects on overall coronary events with estrogen therapy. In fact, there was an increase in CHD events in some women. Mutations in thrombogenic genes (factor V Leiden, prothrombin mutation, etc.) in a subset of women may play a role in this unexpected finding. Thus, the cardioprotective effect of estrogens appears to be more complicated than originally thought and requires more research.

Estrogen replacement therapy and cardioprotection: mechanisms and controversies

Epidemiological and case-controlled studies suggest that estrogen replacement therapy might be beneficial in terms of primary prevention of coronary heart disease (CHD). This beneficial effect of estrogens was initially considered to be due to the reduction of low density lipoproteins (LDL) and to increases in high density lipoproteins (HDL). Recent studies have shown that estrogens protect against oxidative stress and decrease LDL oxidation. Estrogens have direct effects on the arterial tissue and modulate vascular reactivity through nitric oxide and prostaglandin synthesis. While many of the effects of estrogen on vascular tissue are believed to be mediated by estrogen receptors alpha and ß, there is evidence for `immediate non-genomic' effects. The role of HDL in interacting with 17ß-estradiol including its esterification and transfer of esterified estrogens to LDL is beginning to be elucidated. Despite the suggested positive effects of estrogens, two recent placebo-controlled clinical trials in women with CHD did not detect any beneficial effects on overall coronary events with estrogen therapy. In fact, there was an increase in CHD events in some women. Mutations in thrombogenic genes (factor V Leiden, prothrombin mutation, etc.) in a subset of women may play a role in this unexpected finding. Thus, the cardioprotective effect of estrogens appears to be more complicated than originally thought and requires more research

A novel property of an aqueous guaraná extract (Paullinia cupana): inhibition of platelet aggregation in vitro and in vivo

Aqueous extracts of guaraná were studied in terms of effects on the aggregation of human and rabbit platelets. Guaraná extracts have anti-aggregatory and de-aggregatory actions on platelet aggragation induced by ADP or arachidonate but not by collagen. The active material was shown to be water soluble and heat resistant and appeared to be different from salicylates, nicotinic acid or known xanthines. Guaraná extracts inhibited platelet aggregation in rabbits following either intravenous or oral administration