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Biomedical subjects

H van Kessel

Publications and source records attributed to H van Kessel.

At least 37 records · Page 2Linked to original sources
PubMed1984

Estrogen positive feedback on LH secretion in transsexuality.

In order to test the hypothesis whether there is variation in hormonal levels or response to hormonal manipulation that could permit a distinction between heterosexuals and transsexuals, we designed the following protocol: Six male-to-female (m-to-f) transsexuals, six heterosexual control females and six female-to-male (f-to-m) transsexuals were given estradiol benzoate (E2B) (4.5 micrograms/kg/12 hr) for five days. In the female population, E2B treatment was initiated on day 5 of the menstrual cycle. In all the subjects blood luteinizing hormone (LH) and follicle stimulating hormone (FSH), estradiol-17 beta (E2) and testosterone (T) levels were measured twice daily. Additionally, LH and FSH responses to LHRH (100 micrograms iv) stimulation prior to and on day 5 of the E2B treatment were evaluated. In the m-to-f transsexuals, T levels decreased sharply and progressively during estrogen treatment, along with a fall in LH and FSH levels. The magnitude of the LH and FSH responses to LHRH stimulation also decreased following estrogen administration. In the heterosexual female controls and in the f-to-m transsexuals, estrogen administration increased LH levels to a minimum of 100% above initial values from day 3 onwards. Interestingly, the magnitude of the LH increase in the f-to-m transsexuals was greater than that of the heterosexual female controls. In both groups, LHRH stimulation resulted in a greater LH response compared to that prior to estrogen treatment. Our present observations, based on blood hormonal levels and responses to hormonal manipulations do not permit a distinction between heterosexual females and f-to-m transsexuals. There was no convincing evidence for the existence of a positive estrogen feedback on LH secretion in m-to-f transsexuals. These results contradict some of the reported hypotheses concerning hormonal alterations in these individuals.

Adolescent↗
PubMed1984

Prolactin secretion in the human male is increased by endogenous oestrogens and decreased by exogenous/endogenous androgens.

There is evidence that prolactin may be involved in testicular steroidogenesis, and we have therefore investigated whether there is feedback regulation of androgens/oestrogens on prolactin secretion in the human male. To assess this we have measured basal and TRH-stimulated prolactin levels in: Six eugonadal men before and after 2 weeks' administration of the aromatase inhibitor delta'-testolactone, which led to a fall in oestradiol levels with unchanged levels of testosterone. In these patients, prolactin levels decreased. Six eugonadal subjects before and after 6 weeks' administration of dihydrotestosterone undecanoate. In these subjects, prolactin levels decreased. Six agonadal subjects, tested after 12 weeks' treatment with dihydrotestosterone undecanoate and compared to: Six agonadal subjects who received no sex steroid treatment. Again, it was found that dihydrotestosterone treatment decreased prolactin levels in patients from Group C. Six eugonadal subjects were also studied before and after 6 weeks' administration of the androgen receptor antagonist, spironolactone, and this treatment increased Prl secretion. It is concluded that in the human male, endogenous oestrogens increase prolactin secretion whilst exogenous/endogenous androgens decrease prolactin secretion.

Adult↗
PubMed1984

Somatostatin inhibits prolactin release from the lactotroph primed with oestrogen and cyproterone acetate in man.

The present study investigated the effect of administration of somatostatin (SRIF) on the release of prolactin in men. No effect was observed when SRIF was administered to eugonadal men. Release of prolactin was inhibited, however, when SRIF was administered to oestrogen-treated agonadal subjects (male-to-female trans-sexuals) and to an even greater degree when subjects had been pretreated with a combination of oestrogen and cyproterone acetate. This is consistent with findings in the rat. Thus in man, as in the rat, SRIF can inhibit prolactin secretion, but only after treatment with oestrogen.

Adult↗
PubMed1983

Oestrogens induce an LH surge in a prepubertal patient with 45,X gonadal dysgenesis under prolonged pulsatile LRH administration.

A nine year old prepubertal patient with 45,X gonadal dysgenesis received pulsatile LRH administration for 3 weeks, every 90 min 10 micrograms iv. In the first week LH and FSH levels increased from prepubertal levels into the castrate range. Under 2.5 micrograms ethinyloestradiol (EE) LH levelled off for 3 days, followed by an LH surge. FSH showed an ethinyloestradiol dose-dependent decrease. These data suggest that: 1) pulsatile LRH administration may help to distinguish prepubertally those Turner patients with potential ovarian function from those without; 2) oestrogens exert both a negative and positive feedback action at the pituitary level in the LRH treated human; 3) the pituitary does not need 'pubertal maturation' for developing positive feedback to oestrogens. This supports the notion that pubertal maturation is confined to suprapituitary changes.

Child↗
PubMed1983

Induction of ovulation by prolonged pulsatile administration of luteinizing hormone releasing hormone (LRH) in patients with clomiphene resistant polycystic ovary-like disease.

Induction of ovulation with pulsatile administration of LRH by automatic portable infusion pump for 74 and 147 consecutive days in 2 patients with clomiphene resistant PCO-like disease is described. The patients exhibited 6 ovulatory cycles. One patient conceived during the fourth cycle. During the treatment a unilocular cyst, probably a lutein cyst, developed in one patient, but subsequently disappeared spontaneously under uninterrupted therapy. No chemical hyperstimulation was observed. Follicular phases lasted for 32 and 13 days in patient I and for 19, 25, 14 and 22 days in patient II. Luteal phases lasted for 16 and 15 days in patient I and for 17, 18 and 15 days, respectively in patient II. Total urinary oestrogen and pregnanediol excretion did not differ from that seen in normal cycles. LH baseline and peak values and LH responses declined to normal levels accompanied by a normalization of the LH/FSH ratio during pulsatile LRH treatment in both patients. The first pre-ovulatory episode occurred already after partial normalization of the LH/FSH ratio. The endocrinology of the second LRH induced cycles of patients I and II was not different from cycles similarly induced in hypogonadotrophic patients. We conclude that ovulation induction with pulsatile LRH administration in patients with clomiphene resistant PCO-like disease is possible. Our findings give hope that this mode of treatment may not only be effective, but may prove to be safer than ovulation induction with menopausal gonadotrophins in patients with clomiphene resistant PCO-like disease.

Adult↗
PubMed1981

Pregnancy after prolonged pulsatile administration of luteinizing hormone-releasing hormone in a patient with clomiphene-resistant secondary amenorrhea.

Induction of ovulation with LRH, self-administered by the patient (20 microgram every 2 h, iv) from 0700-2300 h continuously for 90 days, is described. Three ovulatory cycles resulted, and the patient conceived during the third cycle. The morning serum LH and FSH concentrations showed a pattern similar to that seen in normal cycles. Total urinary estrogen and pregnanediol excretion did not differ from those in normal cycles. This observation shows that the described mode of treatment is feasible and can result in normal intrauterine pregnancy.

Amenorrhea↗