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Biomedical subjects

W Rohde

Publications and source records attributed to W Rohde.

At least 217 records · Page 12Linked to original sources

Total and free testosterone and total and free 17 beta-oestradiol in normally menstruating women.

Estimations of plasma total and free testosterone (T) as well as of total and free 17beta-oestradiol (E2) have been performed in 6 normal women throughout the menstrual cycle. The plasma total T levels showed a small but significant cyclical variations, with significantly increased values around the midcycle (p less than 0.001). The pattern of free T during the cycle was similar to total T. Regarding total plasma E2, two typical peaks occurred, which were also observed in plasma free E2. Changes in testosterone-17beta-oestradiol binding globulin have not been detected throughout the menstrual cycle.

Estradiol↗

On the evocability of a positive oestrogen feedback action on LH secretion in transsexual men and women.

In transsexual men with homosexual behaviour and intact testicular function, as well as in homosexual men with normal gender identity, following a negative oestrogen feedback effect a delayed positive oestrogen feedback action on LH secretion was evoked. By contrast, in transsexual men with hypo- or asexuality and intact testes or hypergonadotrophic hypo- or agonadism, as well as in heterosexual men with normal gender identity, a negative oestrogen feedback effect was not followed by a positive feedback action on LH release. In transsexual women with homosexual behaviour and oligo- and/or hypomenorrhoea, only a weak or at best moderate positive oestrogen feedback action on LH release was evocable, similarly as in castrated and oestrogen-primed heterosexual men. By contrast, in a transsexual woman with bisexual behaviour and eumenorrhoea, a strong positive oestrogen feedback action on LH secretion was evocable, as well as in heterosexual women with normal gender identity.

Brain↗

A neuroendocrine predisposition for homosexuality in men.

In male rats, androgen deficiency during a critical hypothalamic organizational period was shown to give rise to a predominantly female-differentiated brain, homosexual behavior, and demonstration of a positive estrogen feedback effect. A positive estrogen feedback effect was also induced in intact homosexual men in contrast to intact heterosexual and bisexual men. Thus in 21 homosexual men an intravenous injection of 20 mg Presomen (Premarin) produced a significant decrease of serum LH levels followed by an increase above initial LH values. In 20 heterosexual and in five bisexual men, by contrast, intravenous estrogen administration, while producing a significant decrease of the serum LH level, was not followed by an increase above the initial LH values. Using a radioimmunoassay, plasma testosterone levels and 24-hr urinary excretions of unconjugated testosterone of adult homosexual men were found to be in the normal range as observed in heterosexual men. This finding suggests that homosexual men possess a predominantly female-differentiated brain which may be activated to homosexual behavior by normal or approximately normal androgen levels in adulthood.

Androgens↗

Radioimmunoassay for aldosterone in plasma without chromatography.

A radioimmunoassay without chromatography is described for the determination of plasma aldosterone. The high sensitivity of the method renders possible the detection of about 1 pg aldosterone/ml. The high specificity of the antialdosterone sera (rabbit) may be due to the procedure used for the preparation of aldosterone-21-hemisuccinate and to the intensive purification of the aldosterone-albumin conjugate. The validity of the method was tested by determination of plasma aldosterone in normal subjects and in patients suffering from primary hyperaldosteronism or Addison's disease. In cases of urgent diagnosis, the incubation period was reduced from 16 hours to 1 hour. The elimination of the chromatographic step makes the method suitable for clinical routine work and automatization.

Addison Disease↗

On the evocability of a positive oestrogen feedback action on LH secretion in female and male rats.

Following a single injection of oestradiol benzoate (15 mug/100 g body weight) postpubertally castrated and oestrogen-primed female rats showed a distinct surge of LH secretion, while castrated and androgen-primed females displayed a diminished and delayed surge of LH secretion. On the other hand, postpubertally castrated and oestrogen-primed male rats exhibited only a slight, but significant surge of LH secretion, whereas castrated and androgen-primed males did not display any surge of LH secretion following oestrogen injection. In view of these findings the evocability of a positive oestrogen feedback action on LH secretion is dependent on the sex hormone level during the critical hypothalamic differentiation phase and the functional (priming) phase as well.

Age Factors↗

Studies on the mechanism of the ovulation-inhibiting effect of 19-norsteroids in cyclic rats.

Experiments performed in cyclic female rats demonstrated an equal ovulation-inhibiting activity of the 19-norgestagens norethynodrel, lynestrenol and norethisterone acetate after injection in oestrus and metoestrus, and after daily administration from oestrus to pro-oestrus. The results furthermore show that, after application of the minimal ovulation-inhibiting doses during oestrus and metoestrus, these substances 1. induce an increase in prolactin secretion, 2., with the exception of norethisterone acetate, possess a hypophysial site of action, 3. are able to induce deciduoma formation following traumatization of the uterus, and 4. maintain the reactivity of the cyclic corpora lutea to the injection of prolactin. The findings suggest that the prolactin-releasing and luteotrophic action of the progestagens studied may form an essential part of the mechanisms that are responsible for the inhibition of ovulation observed in rats after administration over one cycle.

Animals↗

Evocability of a slight positive oestrogen feedback action on LH secretion in castrated and oestrogen-primed men.

Orchidectomized heterosexual men suffering from prostatic cancer with suppressed serum LH values by oestrogen priming exhibited a slight, but significant surge of LH secretion following oestrogen injection. In contrast, orchidectomized and oestrogen-primed heterosexual men with unsuppressed serum LH levels as well as intact heterosexual men did not display any positive oestrogen feedback action on LH secretion, as it was observed in intact homosexual men.

Aged↗

An apparently direct inhibitory effect of oestrogen on the human testis.

In men suffering from prostatic cancer, i.v. administration of 12 g diethylstilboestrol diphosphate within 20 days resulted in a decrease of the LH serum level to about 50% (P less than 0.05), whereas the total testosterone level decreased to less than 5% (P less than 0.001) and the apparently free testosterone level to less than 2% of the initial values (P less than 0.001). Hence, the "systemic antiandrogenic effect" of oestrogen can be explained (1) by indirect inhibition of testicular androgen secretion via diminution of hypophyseal gonadotrophin secretion, (2) by direct inhibition of testicular androgen secretion and (3) by elevation of the capacity of testosterone binding beta-globulin.

Aged↗