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Biomedical subjects

G Leyendecker

Publications and source records attributed to G Leyendecker.

At least 91 records · Page 5Linked to original sources
PubMed1975

The role of testosterone in the feedback control of male FSH and LH secretion.

Intramuscular administration of 250 mg testosterone oenanthate per week over a period of 21 weeks treatment rapidly and sustainedly suppressed serum LH as well as FSH levels in seven normal males, while serum testosterone rose by a factor of approximately two. These together with other data provide increasing evidence for a feedback control of FSH secretion by gonadal steroids in the male in addition to the already described but as yet undefined tubular testicular factor.

Adult↗
PubMed1975

[LH, FSH and ovarian steroids in serum during normal menstrual cycles and cycles with corpus luteum insufficiency in the human female (author's transl)].

LH, FSH, estradiol-17beta, progesterone, 20alpha-dihydroprogesterone, 17alpha-hydroxyprogesterone, delta4-androstenedione and testosterone are determined by radioimmunoassay in serum daily during 11 menstrual cycles. Three of them had to be considered as cycles with corpus luteum insufficiency on the basis of basal body temperature, length of the luteal phase and the pattern of progesterone concentration in serum. One woman conceived during the investigated cycle. The present concepts of the regulation of ovulation are discussed on the basis of the chronological relationshp of changing endocrine parameters in serum during the cycles. The analysis of the hormone concentrations in serum during the cycles with corpus luteum insufficiency supports the view that corpus luteum insufficiency could be caused by an insufficient stimulation of the growing follicle, but other ethiological factors have also to be considered.

Adult↗
PubMed1975

Effect of long-term testosterone oenanthate administration on male reproductive function: clinical evaluation, serum FSH, LH, testosterone, and seminal fluid analyses in normal men.

The effect of long-term testosterone administration on male reproductive function has been investigated in seven healthy young men age 20 to 27 years. Testosterone oenanthate (TOe) was administered in doses of 250 mg per week for 21 weeks. No toxic side-effects were observed. Libido, sexual potency, frequency of sexual intercourse and body hair development generally remained unaffected, but there was a reversible mean weight gain of 3.6 kg during TOe administration. Seminal fluid parameters and radioimmunoassayable serum FSH, LH, testosterone, and androstenedione levels were monitored before, during, and after TOe administration. The serum testosterone rose approximately by a factor of two, while the serum FSH and LH were rapidly suppressed after the initiation of the TOe therapy. The mean sperm concentration fell to values below three million spermatozoa per ml, and changes in sperm motility, the percentage of normal sperm morphology, and seminal fructose concentrations generally paralleled those of the mean sperm concentrations. In contrast, the mean seminal fluid volume and serum androstenedione levels did not change significantly during TOe administration. The mean sperm concentration showed a marked recovery 13 to 16 weeks after TOe withdrawal, but sperm counts remained below pre-treatment levels in three out of seven subjects 25 to 28 weeks after discontinuation of TOe.

Adult↗
PubMed1975

[Estradiol-17beta, estrone, LH and FSH in serum after administration of estradiol-17beta, estradiolbenzoate, estradiol-valeriate and estradiol-undecylate in the female (author's transl)].

Estradiol-17beta, estradiol-benzoate, estradiol-valerianate, and estradiol-undecylate were injected intravenously and intramuscularly to postmenopausal woman and to female castrates. Equal doses were used corresponding to 20 mg of free estradiol-17beta. Estradiol-17beta, estrone, FSH and LH were measured in serum by radioimmunoassay before and after application of the hormone and the estradiol esters. Thus the depot effect of the different esters could be compared.

Adult↗