Androgenic, anabolic, estrogenic and antiestrogenic effects of desogestrel and lynestrenol: effects on serum proteins and vaginal cytology

Eight healthy (apart from pelvic endometriosis) women were given daily doses of 0.125, 0.250 and 0.500 mg of desogestrel or 5 mg of lynestrenol orally in a randomized order. Duration of each treatment was 6 weeks. Serum was analyzed for sex hormone binding globulin (SHBG), ceruloplasmin, cortisol binding globulin (CBG), thyroxine binding globulin (TBG) and prealbumin using an electroimmunoassay. Serum 17 beta-estradiol (E2) and testosterone (T) were analyzed by radioimmunoassay. Vaginal cytology was studied using the maturation value (MV). E2 levels were depressed by desogestrel and lynestrenol apart from values in two women after 0.125 mg desogestrel. T concentration was suppressed by desogestrel but not by lynestrenol. SHBG concentration and MV were dose-dependently suppressed indicating an antiestrogenic or possibly androgenic effect of desogestrel and lynestrenol. No androgenic or anabolic effects of desogestrel were however seen, e.g. suppression of TBG content or increase in prealbumin levels. For lynestrenol, however, a small but significant increase in prealbumin concentration indicated a weak androgenic/anabolic effect. No estrogenic effects were seen, e.g. increases in ceruloplasmin, CBG levels or in elevations of MV. A depressed SHBG production ability in the hepatocytes during treatment with 19-nortestosterone derivatives is postulated, possibly due to competitive receptor binding.

Serum levels and pharmacokinetics of norethisterone after ingestion of lynestrenol: its relation to dose and stage of the menstrual cycle

The peak concentration, peak time, the area under the serum concentration time curve (AUC) and half-life of serum norethisterone (NET) after a single application of lynestrenol (LYN) to female volunteers demonstrated that 0.7 mg NET is bioequivalent to 1 mg LYN which is rapidly converted to NET. There was a decrease of the peak values and an increase of half-life of NET during the periovulatory and luteal phase which was, however, not significant due to the great individual differences. The shift of the peak time to longer intervals and the increase of half-life of NET after ingestion of higher LYN doses indicate a certain limitation of the metabolic capacity of the liver. One of the volunteers who complained of nausea and vertigo after the administration of 5 mg LYN, showed the highest serum values of NET. The large interindividual variations of the serum levels of synthetic steroids demonstrate a possible risk of contraceptive safety in women with low steroid levels and possibly a coherence between extremely high serum levels of synthetic steroids and side effects.

[Pharmacokinetics of norethindrone and lynestrenol studied by HPLC (author's transl)]

The concentration of norethindrone in plasma samples from subjects receiving norethindrone (norethisterone) and lynestrenol orally was measured by high pressure liquid chromatography (HPLC). Norethindrone is a synthetic gestagen widely used in contraceptive formulations, and lynestrenol is also a synthetic gestagen which is metabolized to norethindrone in humans. But the evaluation of plasma norethindrone levels in subjects receiving lynestrenol has not yet been reported. After the administration of norethindrone, the peak level of norethindrone in the plasma was obtained within 2h, and the peak concentration in the plasma was about 3.5 ng/ml/mg norethindrone. During a period of 2-6hs after the administration of norethindrone, the half life of norethindrone in the plasma was approximately 1.8h, and during the period of 6-24hs, half life was variable. On the other hand, after the administration of lynestrenol, the peak level of norethindrone in the plasma was obtained within 4h, and the peak concentration of norethindrone was about 1.9 ng/ml/mg lynestrenol. During a period of 4-12hs, the half life of norethindrone was about 2.5h. The peak of the norethindrone level after the administration of lynestrenol was lower and appeared later than that after the administration of the same dose of norethindrone. Norethindrone in plasma in subjects receiving lynestrenol could be measured for a longer period than in those receiving the same dose of norethindrone. These results suggest that lynestrenol is stored in fat tissue and is slowly metabolized to norethindrone.

Focal nodular hyperplasia of the liver and contraceptive steroids

A case of Focal Nodular Hyperplasia of the liver in a young woman taking oral contraceptives is described. The parenteral administration of an elevated dosage of progesterone in a concentrated period of time is a remarkable feature of this case. The vascular alterations, which consisted of a marked increase of arterial and venous formations, intimal proliferation, diffused thrombosis, and the presence of large blood spaces recalling "peliosis hepatis" are the most salient microscopic findings. We should not exclude the possibility that these peculiar vascular alterations be the real effect of steroid hormones on a pre-existent hepatic lesion.

The contraceptive effects of a new low-dose combination type oral contraceptive

A study was carried out in 9 women volunteers to investigate the centron of 0.75 mg lynestrenol plus 0.0375 mg ethinyl oestradiol given for 22 days per cycle over a period of 6 cycles. The results of assessments of a number of hormonal, vaginal and cervical parameters showed that this combination has a two-fold effect: a central effect on the pituitary and a peripheral effect on the ovaries and on endometrial development. The findings of an effect on cervical mucus, as with higher dose combinations, were not sufficiently consistent to warrant a claim for a cervical barrier. The preparation appeared to be well tolerated but there was a high incidence of irregular bleeding in the first treatment cycle. In most of the women, however, this had corrected itself by the second cycle.

Comparison of ethinylestradiol and mestranol in sequential-type oral contraceptives in their effects on blood glucose and serum insulin in oral glucose tolerance tests

Forty 3-hour oral glucose tolerance tests (OGTTs) were performed in 10 assumedly healthy female volunteers 19 to 30 years old, each serving four times as her own control. Each subject was taking a sequential type oral contraceptive containing either 50 microgram of ethinylestradiol or 80 microgram of mestranol alternatingly in four consecutive treatment cycles. The OGTTs were performed on the 6th day of each cycle, during pure estrogen medication. Blood glucose and serum insulin values did not differ significantly under either estrogen as tested by the t-test for paired observations. Our results do not support the findings of others that mestranol has a more pronounced or even exclusively adverse effect on glucose tolerance as compared with ethinylestradiol.

[Central and peripheral actions of an oral contraceptive with reduced oestrogen content (author's transl)]

The action spectrum of an oral contraceptive which contained a reduced amount of the oestrogen component (0.04 mg ethinyl-oestradiol and 2.0 mg lynoestrenol) was investigated in 4 volunteer subjects. Serum levels of LH, 17 beta-oestradiol and progesterone were determined by radioimmunoassay and, in addition, the karyopyknotic index and cervical function were studied daily from the 8th day of the cycle. These parameters were determined in a control cycle, in the cycle during administration of the oral contraceptive and in the subsequent treatment-free cycle. Furthermore, the bleeding patterns were studied in 284 treatment cycles of 26 patients. Results of these studies indicate complete contraceptive protection by inhibition of ovulation and by an efficient cervical barrier action already during the first treatment cycle. Withdrawal bleeding was observed 3 to 4 days after ingestion of the last tablet. Spotting was recorded in 11 subjects during the first treatment cycle but was rarely observed during further treatment. Blood loss and bleeding control is comparable to that of other combined oral contraceptives with reduced oestrogen content.

Lack of influence of the phase of estrus cycle or treatment with steroid contraceptive drugs on cholinergic parameters in mouse and rat brain

Acetylcholine and choline levels were found not to fluctuate with the phase of the estrus cycle in the cerebral hemispheres, deincephalon and mesencephalon in the rat and mouse. Choline acetyltransferase activity was not altered in these brain areas in the mouse while in the rat there was a small but significant decrease in the cerebral hemispheres during proestrus (p less than 0.01), and in the mesencephalon during estrus (p less than 0.05), both with respect to diestrus. Chronic 30-day treatment with steroid contraceptive drug combinations (lynestrenol, 5 mg/kg+ mestranol, 0.3 mg/kg; lynestrenol, 2.5 mg/kg+ mestranol, 0.15 mg/kg; norethindrone, 4 mg/kg+ mestranol, 0.2 mg/kg; norethynodrel, 4 mg/kg+ mestranol, 0.06 mg/kg) did not alter cholinergic parameters in the brain areas of these two species except for minor changes in rare instances.

Biochemical effects of treatment with oral contraceptive steroids on the dopaminergic system of the rat

The effects of acute and chronic administration of a combination of lynestrenol-mestrenol, a widely employed contraceptive medication, on the dopaminergic system of the rat forebrain and striatum were investigated to better understand the biochemical basis of the neurological side-effects of steroid contraceptive drugs (SCDs). Both acute and chronic treatment increased the disappearance rate of striatal dopamine (DA) after synthesis blockade with alpha-methyl-p-tyrosine (alpha-MpT). Moreover, the conversion of 3H-tyrosine (3H-T) into 3H-DA was increased in the forebrain and striatum after chronic administration of this steroid combination. In the same animals, the utilization of tyrosine (T) is increased.

Malignant hypertension with irreversible renal failure due to oral contraceptives

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A clinical impression of a combination-type contraceptive: Neo-Lyndiol

One hundred and sixty-five women were treated during a total of 3,281 cycles with Neo-Lyndiol, a combined oral contraceptive containing 2·5 mg lynestrenol and 0·050 mg ethinyloestradiol per tablet. The tablets were taken for 32 days, with six tablet-free days.

No pregnancies were seen and the proportion of patients experiencing irregular bleeding and side-effects was very low and in fact their complaints decreased considerably as medication continued. There was a drop-out rate of only 5·5%, which is exceptionally low.

Neo-Lyndiol proved to be a reliable preparation, controlling the cycle well and causing few side-effects.

Urinary hormone excretion patterns during low-dose progestogen administration

The effects on pituitary-ovarian function of long-term administration of 0·5 mg of lynestrenol and 0·35 mg of norethisterone in continuous daily doses were investigated in 9 female subjects. The parameters employed were the basal body temperature charts and urinary assays of LH, total oestrogen and pregnanediol.

At the start of administration, ovulation was usually inhibited, but as a rule this effect disappeared as administration continued. Corpus luteum function appeared to be reduced.

Clinical evaluation of a new oral contraceptive, 'Pregnon'

'Pregnon', a new oral contraceptive containing 1 mg. lynestrenol and 0.05 mg. ethinyl oestradiol, was administered cyclically to 639 women of fertile age over a total of 9,159 cycles. There were no pregnancies. In most cases the withdrawal bleeding resembled normal menstruation. The incidence of metrorrhagia was relatively low and when it did occur it was usually confined to the early treatment cycles and was of very limited duration. The objective and subjective tolerance was excellent.

Effect of selective lesioning of brain serotonin or catecholamine-containing neurons on the activity of oral steroid contraceptives in rats

The effect of different dosage combinations of lynoestrenol and mestranol were studied in rats that have been subjected to selective lesioning of brain serotonin or catecholamine-containing neurons. Lesions of the midbrain raphe, which cause a marked decrease of serotonin in the forebrain, were without any effect on the estrus cycle, fertility and activity of the steroids under study. An intraventricular injection of 6-hydroxydopamine, which causes a selective decrease of noradrenaline and dopamine in the forebrain, produced a transient effect only on the estrus cycle but did not significantly change the fertility or the activity of the substances investigated. The data indicate that the integrity of monoaminergic neurons in the brain is not an essential condition for the aspects investigated in the present study.