Showing papers by "Henry G. Burger published in 1991"

Serum Gonadotropin, Sex Steroid, and Immunoreactive Inhibin Levels in the First Two Years of Life

Abstract: To characterize the changes in serum immunoreactive inhibin (INH) in the first 2 yr of life, blood samples were obtained from 46 boys (age range, 61-659 days) and 37 girls (76-666 days) undergoing minor surgery for nonendocrine related conditions. Serum levels were compared with those of simultaneously measured FSH, LH, and either testosterone (T) or estradiol (E2). In the boys, the levels of all 4 hormones fell progressively with age up to about 300 days, with a minor fall only in the second year. FSH (0.7-1.4 IU/L) was initially at the lower adult male limit, while LH (3.2-5.0 IU/L) was at the midrange. T levels (2.2-3.3 nmol/L) were in the adult female range, while INH (200-820 U/L) was in the midrange for men. In the youngest girls, FSH levels (12-26 IU/L) were frequently above the upper limit of normal for the adult follicular phase, but fell to approximately 2.0 IU/L after 300 days. LH levels (0.5-3.5 IU/L) were at the lower adult normal limit and changed little with age, while E2 levels in the youngest girls (280-550 pmol/L) were in the midfollicular range, but were generally less than 10 pM at more than 200 days. INH levels (175-260 U/L) were in the low adult range initially, but the majority were undetectable over 200 days. In the boys, significant negative correlations were observed for all 4 hormones with age, while FSH, LH, and T were positively correlated with INH. In the girls, there were weaker negative correlations of the 4 hormones with age, but no significant correlations between the gonadotropins and INH. E2 was strongly correlated with INH. Thus, the previously described early postnatal activation of the hypothalamo-pituitary-gonadal axis involves INH as well as the se steroids and gonadotropins. FSH levels in young girls were strikingly high, and INH levels were much higher in boys than girls. The low INH levels in girls may contribute to the elevated FSH seen during the period of neonatal gonadal activation.

Ovarian sensitization to gonadotrophins by human growth hormone. Persistence of the effect beyond the treated cycle

Abstract: Summary. objective To document the persistence of a sensitizing effect of human growth hormone on the ovarian responsiveness to human menopausal gonadotrophin in anovulatory patients resistant to standard gonadotrophin doses. DESIGN We performed an open study of three patients given 4, 12 or 24 IU recombinant growth hormone on alternate days for 5–7 doses, concomitantly with gonadotrophin, and assessed gonadotrophin dose requirements before, during and after the cycle of growth hormone therapy. patients We studied two with isolated gonadotrophin deficiency and primary amenorrhoea and one with a pituitary tumour and hyperprolactinaemia which normalized with bromocriptine but in whom there was persisting secondary amenorrhoea. measurements We measured body mass Index, FSH, LH, prolactin, growth hormone, insulin-like growth factor I (IGF-I), oestradiol and Inhibin at baseline and growth hormone, IGF-I, oestradiol and inhibin during treatment. In addition we noted the numbers of ampoules (75IU) and the last pre-hCG dose of gonadotrophin used before, during and after growth hormone therapy. results Baseline growth hormone levels were low but IGF-I levels were normal. IGF-I Increased by 20% in the subject given 4 IU growth hormone, and by 50–100% in the other two. Pretreatment dally gonadotrophin dosage of 8–11 ampoules pre-hCG was reduced to 3–6 ampoules during growth hormone and 3–4 post growth hormone. This effect persisted for 4 cycles over 7 months in one subject. conclusion Growth hormone causes persisting ovarian sensitization to gonadotrophin and may produce a substantial lowering of gonadotrophin requirement for ovulation induction in patients with large dosage needs

Circulating levels of inhibin in pregnant women at term: simultaneous disappearance with oestradiol and progesterone after delivery

Abstract: Circulating levels of immunoreactive inhibin (ir-inhibin) and its disappearance after delivery of the placenta were determined in seven pregnant women at term. Serum oestradiol (E2) and progesterone (P4) levels were measured simultaneously and served as comparisons. Fetal contributions of ir-inhibin were assessed by determining concentrations in the umbilical artery (UA) and vein (UV). Relative changes in circulating levels of ir-inhibin, E2, and P4 were compared to levels found in nonpregnant women during the early follicular phase (EFP) and mid-luteal phase (MLP) of the normal menstrual cycle. In pregnant women, ir-inhibin levels at delivery were 15- and 3-fold higher than EFP and MLP values respectively. The disappearance of all three hormones after removal of the placenta followed a bi-exponential curve with an initial, rapid component and a second, slower component. There was a highly significant positive correlation between the disappearance curves of all three placental hormones (r = 0.97, P less than 0.0001). Concentrations of ir-inhibin in the cord blood were about half that in maternal serum and without significant difference between levels in UA and UV.

Inhibin and age in men.

Abstract: Summary. objective Normal elderly men are reported to have decreased testicular function despite elevated gonadotrophin levels. We wished therefore to determine If changes in testicular function occur over the age range 19–80 years. design Single fasting blood samples were obtained between 0800 and 0900 h. patients Working men In a large Industrial company between the ages of 19 and 60 years participated in the study. measurements fsh, serum immunoreactive Inhibin and total testosterone were measured, the latter two as measurements of Sertoll and Leydig cell function respectively. results The mean baseline serum Immunoreactive inhibin level was significantly lower in men from the older age groups, 31–40 years (479 U/I), 41–50 years (439 U/I) and 51–60 years (415 U/I) than in men from the youngest age group, 21–30 years (613 U/I) while serum FSH was higher in men from the older age groups, 41–50 years (3.7 IU/I) and 51–60 years (6.1 IU/I) than In men from the youngest age group, 21–30 years (2.6 IU/I). There appears to be a change in both FSH and inhibin production, consistent with a primary decline In testicular function. There was no significant difference in testosterone levels between the older age group, age 51–60 years and the younger age group, age 21–30 years. However, testosterone levels were significantly lower in the 41–50 year age group, when compared with the 21–30 year, this significance levelling out at about age 45 years. conclusion The data are consistent with the hypothesis that Immunoreactive inhibin reflects Inhibin bioactivity, and that inhibin plays a role in the feedback control of FSH secretion in men.