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Inhibition of ovulation in women by chronic treatment with a stimulatory LRH analogue--a new approach to birth control?

A stimulatory luteinizing hormone-releasing hormone (LRH) analogue D-Ser(TBU)6-EA10-LRH was administered subcutaneously once daily in a dose of 5 microgram to four regularly menstruating women. Treatment was instituted within the first three days of the menstrual bleeding and continued for 22--30 days. Ovulation was inhibited in all the women during the treatment cycle. The treatment resulted in disturbances in the pituitary gonadotropin secretion which presumably led to disordered follicular menuration and anovulation. The maximum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) responses to the LRH analogue were obtained during the first few days of treatment. The gonadotropin responses then rapidly decreased during the prolonged treatment. This change in the pituitary responsiveness probably prevented the release of a normal preovulatory LH surge. After the treatment, all the women resumed normal ovulatory menstrual cycles. The results suggest that it might be possible to use stimulatory LRH analogues for birth control.

Adult↗

Binding of steroids to blastokinin.

The authors studied the binding of steroids with Blastokinin (BKN). They confirm that progesterone is the steroid that has a greater affinity for BKN than estradiol or testosterone; the latter is hardly bound to the protein at all. They also show that the presence of estradiol interferes with the formation phase of the BKN-progesterone complex, while testosterone does not. When the BKN-progesterone complex is already formed, a release of the progesterone occurs only when there is a double concentration of estradiol. The biological importance of this phenomenon is briefly discussed.

Animals↗

[Sex hormone regulation of progesterone and estradiol receptors in the cytosol of human endometrium in normal and pathologic pregnancy].

Hormonal control of progesterone and estradiol receptors was studied in the cytozol of short-lived culture of human endometrium in normal and undeveloping pregnancy. Endometrium was cultivated in the presence of estradiol or progesterone for 16 hours. In cultivation of normal endometrium with estradiol the content of estradiol receptors increased 4-fold in comparison with unstimulated tissue, and of progesteron receptors--3-fold. In cultivation of normal endometrium with progesterone the content of estradiol receptors rose 4--5-fold, and of progesterone receptors--3-fold. In cultivation of pathological endometrium with estradiol or progesterone the number of estradiol receptors was only doubled, and of progesterone receptors--increased only 1 1/2 times, this pointing to a diminished sensitivity of pathological endometrium to the regulating action of sex hormones.

Cells, Cultured↗

Clinics in endocrinology and metabolism. Investigative procedures.

In patients with hypogonadism, the exact cause of the deficient androgenisation is not always clinically apparent. The data presented demonstrate that by means of hormone measurements, basally or after stimulation tests, the exact level of the lesion can usually be determined. This allows a decision with regard to appropriate therapy to be made on the basis of an accurate diagnosis. In many instances basal measurements of pituitary and gonadal hormones are all that is required to decide the level of the lesion. Care in interpreting basal levels is required, however, in view of methodological limitations and of known physiological variations with age, time of day and hour-to-hour fluctuations. If the basal hormone levels are borderline, or if the 'reserve function' of part or all of the hypothalamic-pituitary-gonadal axis needs to be assessed, than the appropriate stimulation test should be performed. The indication for these stimulation procedures and results obtained in different conditions are described and problems of interpretation discussed.

Adult↗

Pituitary and gonadal function during the use of progesterone- or progesterone-estradiol-releasing vaginal rings.

Six women used polysiloxane vaginal rings impregnated with progesterone, or progesterone and estradiol. Nineteen 3-week treatment cycles were studied. Subjects kept records of bleeding. Plasma progesterone, estradiol, and gonadotropins were measured by radioimmunoassay. The patient acceptance was poor. None of the subjects experienced regular withdrawal bleedings during the treatment-free week. Fifty-three percent of the cycles were ovulatory as judged by plasma progesterone, but the plasma concentration of progesterone was low during the luteal phase. However, no pregnancies were discovered during the study period. Several high estradiol peaks were present during the treatment. Plasma LH fluctuated in the range of the normal menstrual cycle. Some suppression of plasma FSH was observed. The combination of estradiol and progesterone in the rings caused stronger suppression of FSH, but no diminution in the rate of ovulations or in disturbances of bleeding were observed in comparison to rings impregnated only with progesterone. Rings released the same amounts of progesterone in vitro and produced plasma concentrations which varied between 0.4 and 1.9 ng/ml.

Adult↗