The Effects of Some Ovulation Inhibitors on the Different Plasma Lipid Fractions

Abstract

A comparison has been made of the effects of three different combined oral contraceptives (Ovulen, Anovlar, and Volidan) on the plasma levels of cholesterol, triglycerides, and total and individual phospholipids. The results indicate a difference in action between Anovlar on the one hand and of Ovulen and Volidan on the other. In three oophorectomized women the effects of one of the estrogenic and two of the progestogenic components of the combined preparations were studied separately. The drugs were given singly or in combinations and it was found that the two progestogens produced different effects as judged from the parameters studied. Norethisterone acetate influenced the plasma lipids in a direction opposite to that induced by the estrogen. These findings suggest that the overall effects on the plasma lipids induced by the various combined oral contraceptives reflect the competitional effects of the estrogenic and progestogenic components.

Effects of an Oral Contraceptive Agent on Plasma Lipids, Plasma Lipoproteins, the Intravenous Fat Tolerance and the Post‐heparin Lipoprotein Lipase Activity

“…The results confirmed earlier studies which have shown increased plasma concentration of cholesterol and triglycerides (1,9,14,15,17,23) and decreased post-heparin lipolytic activity (1 5 ) during treatment with estrogen-containing oral contraceptives. Larsson-Cohn et al (17), employing the same agent as used in the present study, observed a decrease of plasma FFA.…”

“…Oral contraceptive agents may raise the plasma triglyceride level (1,9,14,15,17,23). Hazzard et al (15) found that concomitantly with a raised concentration of plasma triglycerides there was a decrease of the post-heparin lipolytic activity and an increase of the basal plasma level of immunoreactive insulin, These authors discussed the possibility that the raised level of plasma triglycerides might be due to impaired removal from plasma related to the decrease in lipolytic activity.…”

Influence of Nicotinic Acid on Individual Plasma Phospholipids in Hypercholesterolemic Subjects

“…Further investigations in this direction may be indicated, as estrogens have a well-known lipidlowering effect (13,22). 7 he lysolecithin in plasma seems mainly io b: produced from lecithin via the acyl-transferase mechanism described by Glomset (1 6). Possibly also phospholipase A may be of importance (5).…”